| Message ID | 20220120001621.705352-2-jsd@semihalf.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | i2c-designware: Add support for AMD PSP semaphore | expand |
Hi, On 1/20/22 01:16, Jan Dabros wrote: > All accesses to controller's registers should be protected on > probe, disable and xfer paths. This is needed for i2c bus controllers > that are shared with but not controller by kernel. > > Signed-off-by: Jan Dabros <jsd@semihalf.com> Thanks, patch looks good to me: Reviewed-by: Hans de Goede <hdegoede@redhat.com> Regards, Hans > --- > drivers/i2c/busses/i2c-designware-common.c | 12 ++++++++++++ > drivers/i2c/busses/i2c-designware-master.c | 6 ++++++ > 2 files changed, 18 insertions(+) > > diff --git a/drivers/i2c/busses/i2c-designware-common.c b/drivers/i2c/busses/i2c-designware-common.c > index bf2a4920638a..9f8574320eb2 100644 > --- a/drivers/i2c/busses/i2c-designware-common.c > +++ b/drivers/i2c/busses/i2c-designware-common.c > @@ -578,7 +578,12 @@ int i2c_dw_set_fifo_size(struct dw_i2c_dev *dev) > * Try to detect the FIFO depth if not set by interface driver, > * the depth could be from 2 to 256 from HW spec. > */ > + ret = i2c_dw_acquire_lock(dev); > + if (ret) > + return ret; > + > ret = regmap_read(dev->map, DW_IC_COMP_PARAM_1, ¶m); > + i2c_dw_release_lock(dev); > if (ret) > return ret; > > @@ -607,6 +612,11 @@ u32 i2c_dw_func(struct i2c_adapter *adap) > void i2c_dw_disable(struct dw_i2c_dev *dev) > { > u32 dummy; > + int ret; > + > + ret = i2c_dw_acquire_lock(dev); > + if (ret) > + return; > > /* Disable controller */ > __i2c_dw_disable(dev); > @@ -614,6 +624,8 @@ void i2c_dw_disable(struct dw_i2c_dev *dev) > /* Disable all interrupts */ > regmap_write(dev->map, DW_IC_INTR_MASK, 0); > regmap_read(dev->map, DW_IC_CLR_INTR, &dummy); > + > + i2c_dw_release_lock(dev); > } > > void i2c_dw_disable_int(struct dw_i2c_dev *dev) > diff --git a/drivers/i2c/busses/i2c-designware-master.c b/drivers/i2c/busses/i2c-designware-master.c > index 9177463c2cbb..1a4b23556db3 100644 > --- a/drivers/i2c/busses/i2c-designware-master.c > +++ b/drivers/i2c/busses/i2c-designware-master.c > @@ -905,7 +905,13 @@ int i2c_dw_probe_master(struct dw_i2c_dev *dev) > irq_flags = IRQF_SHARED | IRQF_COND_SUSPEND; > } > > + ret = i2c_dw_acquire_lock(dev); > + if (ret) > + return ret; > + > i2c_dw_disable_int(dev); > + i2c_dw_release_lock(dev); > + > ret = devm_request_irq(dev->dev, dev->irq, i2c_dw_isr, irq_flags, > dev_name(dev->dev), dev); > if (ret) { >
Hi, Adding proper Andy's email address (and removing wrong one) in the whole patchset. Sorry for noise! Best Regards, Jan pt., 28 sty 2022 o 15:48 Jan Dabros <jsd@semihalf.com> napisał(a): > > Implement an I2C controller sharing mechanism between the host (kernel) > and PSP co-processor on some platforms equipped with AMD Cezanne SoC. > > On these platforms we need to implement "software" i2c arbitration. > Default arbitration owner is PSP and kernel asks for acquire as well > as inform about release of the i2c bus via mailbox mechanism. > > +---------+ > <- ACQUIRE | | > +---------| CPU |\ > | | | \ +----------+ SDA > | +---------+ \ | |------- > MAILBOX +--> | I2C-DW | SCL > | +---------+ | |------- > | | | +----------+ > +---------| PSP | > <- ACK | | > +---------+ > > +---------+ > <- RELEASE | | > +---------| CPU | > | | | +----------+ SDA > | +---------+ | |------- > MAILBOX +--> | I2C-DW | SCL > | +---------+ / | |------- > | | | / +----------+ > +---------| PSP |/ > <- ACK | | > +---------+ > > The solution is similar to i2c-designware-baytrail.c implementation, where > we are using a generic i2c-designware-* driver with a small "wrapper". > > In contrary to baytrail semaphore implementation, beside internal > acquire_lock() and release_lock() methods we are also applying quirks to > lock_bus() and unlock_bus() global adapter methods. With this in place > all i2c clients drivers may lock i2c bus for a desired number of i2c > transactions (e.g. write-wait-read) without being aware of that such bus > is shared with another entity. > > Modify i2c_dw_probe_lock_support() to select correct semaphore > implementation at runtime, since now we have more than one available. > > Configure new matching ACPI ID "AMDI0019" and register > ARBITRATION_SEMAPHORE flag in order to distinguish setup with PSP > arbitration. > > Add myself as a reviewer for I2C DesignWare in order to help with reviewing > and testing possible changes touching new i2c-designware-amdpsp.c module. > > Signed-off-by: Jan Dabros <jsd@semihalf.com> > Reported-by: kernel test robot <lkp@intel.com> > Reported-by: kernel test robot <lkp@intel.com> > --- > MAINTAINERS | 1 + > drivers/acpi/acpi_apd.c | 7 +- > drivers/i2c/busses/Kconfig | 11 + > drivers/i2c/busses/Makefile | 1 + > drivers/i2c/busses/i2c-designware-amdpsp.c | 373 +++++++++++++++++++ > drivers/i2c/busses/i2c-designware-baytrail.c | 10 +- > drivers/i2c/busses/i2c-designware-core.h | 18 +- > drivers/i2c/busses/i2c-designware-platdrv.c | 61 +++ > 8 files changed, 471 insertions(+), 11 deletions(-) > create mode 100644 drivers/i2c/busses/i2c-designware-amdpsp.c > > diff --git a/MAINTAINERS b/MAINTAINERS > index f41088418aae..e0a7e05c5a41 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -18666,6 +18666,7 @@ SYNOPSYS DESIGNWARE I2C DRIVER > M: Jarkko Nikula <jarkko.nikula@linux.intel.com> > R: Andy Shevchenko <andriy.shevchenko@linux.intel.com> > R: Mika Westerberg <mika.westerberg@linux.intel.com> > +R: Jan Dabros <jsd@semihalf.com> > L: linux-i2c@vger.kernel.org > S: Maintained > F: drivers/i2c/busses/i2c-designware-* > diff --git a/drivers/acpi/acpi_apd.c b/drivers/acpi/acpi_apd.c > index e7934ba79b02..ad245bbd965e 100644 > --- a/drivers/acpi/acpi_apd.c > +++ b/drivers/acpi/acpi_apd.c > @@ -232,12 +232,13 @@ static const struct acpi_device_id acpi_apd_device_ids[] = { > /* Generic apd devices */ > #ifdef CONFIG_X86_AMD_PLATFORM_DEVICE > { "AMD0010", APD_ADDR(cz_i2c_desc) }, > - { "AMDI0010", APD_ADDR(wt_i2c_desc) }, > { "AMD0020", APD_ADDR(cz_uart_desc) }, > - { "AMDI0020", APD_ADDR(cz_uart_desc) }, > - { "AMDI0022", APD_ADDR(cz_uart_desc) }, > { "AMD0030", }, > { "AMD0040", APD_ADDR(fch_misc_desc)}, > + { "AMDI0010", APD_ADDR(wt_i2c_desc) }, > + { "AMDI0019", APD_ADDR(wt_i2c_desc) }, > + { "AMDI0020", APD_ADDR(cz_uart_desc) }, > + { "AMDI0022", APD_ADDR(cz_uart_desc) }, > { "HYGO0010", APD_ADDR(wt_i2c_desc) }, > #endif > #ifdef CONFIG_ARM64 > diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig > index 42da31c1ab70..3ba9e7f9366e 100644 > --- a/drivers/i2c/busses/Kconfig > +++ b/drivers/i2c/busses/Kconfig > @@ -553,6 +553,17 @@ config I2C_DESIGNWARE_PLATFORM > This driver can also be built as a module. If so, the module > will be called i2c-designware-platform. > > +config I2C_DESIGNWARE_AMDPSP > + bool "AMD PSP I2C semaphore support" > + depends on X86_64 > + depends on ACPI > + depends on I2C_DESIGNWARE_PLATFORM > + help > + This driver enables managed host access to the selected I2C bus shared > + between AMD CPU and AMD PSP. > + > + You should say Y if running on an AMD system equipped with the PSP. > + > config I2C_DESIGNWARE_BAYTRAIL > bool "Intel Baytrail I2C semaphore support" > depends on ACPI > diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile > index 1d00dce77098..752f47be3fc1 100644 > --- a/drivers/i2c/busses/Makefile > +++ b/drivers/i2c/busses/Makefile > @@ -54,6 +54,7 @@ i2c-designware-core-y += i2c-designware-master.o > i2c-designware-core-$(CONFIG_I2C_DESIGNWARE_SLAVE) += i2c-designware-slave.o > obj-$(CONFIG_I2C_DESIGNWARE_PLATFORM) += i2c-designware-platform.o > i2c-designware-platform-y := i2c-designware-platdrv.o > +i2c-designware-platform-$(CONFIG_I2C_DESIGNWARE_AMDPSP) += i2c-designware-amdpsp.o > i2c-designware-platform-$(CONFIG_I2C_DESIGNWARE_BAYTRAIL) += i2c-designware-baytrail.o > obj-$(CONFIG_I2C_DESIGNWARE_PCI) += i2c-designware-pci.o > i2c-designware-pci-y := i2c-designware-pcidrv.o > diff --git a/drivers/i2c/busses/i2c-designware-amdpsp.c b/drivers/i2c/busses/i2c-designware-amdpsp.c > new file mode 100644 > index 000000000000..9b600ca54f7c > --- /dev/null > +++ b/drivers/i2c/busses/i2c-designware-amdpsp.c > @@ -0,0 +1,373 @@ > +// SPDX-License-Identifier: GPL-2.0 > + > +#include <linux/bitfield.h> > +#include <linux/i2c.h> > +#include <linux/io-64-nonatomic-lo-hi.h> > +#include <linux/psp-sev.h> > +#include <linux/types.h> > + > +#include <asm/msr.h> > + > +#include "i2c-designware-core.h" > + > +#define MSR_AMD_PSP_ADDR 0xc00110a2 > +#define PSP_MBOX_OFFSET 0x10570 > +#define PSP_CMD_TIMEOUT_MS 500 > + > +#define PSP_I2C_REQ_BUS_CMD 0x64 > +#define PSP_I2C_REQ_RETRY_CNT 10 > +#define PSP_I2C_REQ_RETRY_DELAY_USEC (50 * 1000) > +#define PSP_I2C_REQ_STS_OK 0x0 > +#define PSP_I2C_REQ_STS_BUS_BUSY 0x1 > +#define PSP_I2C_REQ_STS_INV_PARAM 0x3 > + > +#define PSP_MBOX_FIELDS_STS GENMASK(15, 0) > +#define PSP_MBOX_FIELDS_CMD GENMASK(23, 16) > +#define PSP_MBOX_FIELDS_RESERVED GENMASK(29, 24) > +#define PSP_MBOX_FIELDS_RECOVERY BIT(30) > +#define PSP_MBOX_FIELDS_READY BIT(31) > + > +struct psp_req_buffer_hdr { > + u32 total_size; > + u32 status; > +}; > + > +enum psp_i2c_req_type { > + PSP_I2C_REQ_ACQUIRE, > + PSP_I2C_REQ_RELEASE, > + PSP_I2C_REQ_MAX > +}; > + > +struct psp_i2c_req { > + struct psp_req_buffer_hdr hdr; > + enum psp_i2c_req_type type; > +} __aligned(32); > + > +struct psp_mbox { > + u32 cmd_fields; > + phys_addr_t i2c_req_addr; > +} __packed; > + > +static DEFINE_MUTEX(psp_i2c_access_mutex); > +static unsigned long psp_i2c_sem_acquired; > +static void __iomem *mbox_iomem; > +static u32 psp_i2c_access_count; > +static bool psp_i2c_mbox_fail; > +static struct device *psp_i2c_dev; > + > +/* > + * Implementation of PSP-x86 i2c-arbitration mailbox introduced for AMD Cezanne > + * family of SoCs. > + */ > + > +static int psp_get_mbox_addr(unsigned long *mbox_addr) > +{ > + unsigned long long psp_mmio; > + > + if (rdmsrl_safe(MSR_AMD_PSP_ADDR, &psp_mmio)) > + return -EIO; > + > + *mbox_addr = (unsigned long)(psp_mmio + PSP_MBOX_OFFSET); > + > + return 0; > +} > + > +static int psp_mbox_probe(void) > +{ > + unsigned long mbox_addr; > + int ret; > + > + ret = psp_get_mbox_addr(&mbox_addr); > + if (ret) > + return ret; > + > + mbox_iomem = ioremap(mbox_addr, sizeof(struct psp_mbox)); > + if (!mbox_iomem) > + return -ENOMEM; > + > + return 0; > +} > + > + > +/* Recovery field should be equal 0 to start sending commands */ > +static int psp_check_mbox_recovery(struct psp_mbox __iomem *mbox) > +{ > + u32 tmp; > + > + tmp = readl(&mbox->cmd_fields); > + > + return FIELD_GET(PSP_MBOX_FIELDS_RECOVERY, tmp); > +} > + > +static int psp_wait_cmd(struct psp_mbox __iomem *mbox) > +{ > + u32 tmp, expected; > + > + /* Expect mbox_cmd to be cleared and ready bit to be set by PSP */ > + expected = FIELD_PREP(PSP_MBOX_FIELDS_READY, 1); > + > + return readl_poll_timeout(&mbox->cmd_fields, tmp, (tmp == expected), > + 0, 1000 * PSP_CMD_TIMEOUT_MS); > +} > + > +/* Status equal to 0 means that PSP succeed processing command */ > +static int psp_check_mbox_sts(struct psp_mbox __iomem *mbox) > +{ > + u32 cmd_reg; > + > + cmd_reg = readl(&mbox->cmd_fields); > + > + return FIELD_GET(PSP_MBOX_FIELDS_STS, cmd_reg); > +} > + > +static int psp_send_cmd(struct psp_i2c_req *req) > +{ > + struct psp_mbox __iomem *mbox = (struct psp_mbox __iomem *)mbox_iomem; > + phys_addr_t req_addr; > + u32 cmd_reg; > + > + if (psp_check_mbox_recovery(mbox)) > + return -EIO; > + > + if (psp_wait_cmd(mbox)) > + return -EBUSY; > + > + /* > + * Fill mailbox with address of command-response buffer, which will be > + * used for sending i2c requests as well as reading status returned by > + * PSP. Use physical address of buffer, since PSP will map this region. > + */ > + req_addr = __psp_pa((void *)req); > + writeq(req_addr, &mbox->i2c_req_addr); > + > + /* Write command register to trigger processing */ > + cmd_reg = FIELD_PREP(PSP_MBOX_FIELDS_CMD, PSP_I2C_REQ_BUS_CMD); > + writel(cmd_reg, &mbox->cmd_fields); > + > + if (psp_wait_cmd(mbox)) > + return -ETIMEDOUT; > + > + if (psp_check_mbox_sts(mbox)) > + return -EIO; > + > + return 0; > +} > + > +/* Helper to verify status returned by PSP */ > +static int check_i2c_req_sts(struct psp_i2c_req *req) > +{ > + int status; > + > + status = readl(&req->hdr.status); > + > + switch (status) { > + case PSP_I2C_REQ_STS_OK: > + return 0; > + case PSP_I2C_REQ_STS_BUS_BUSY: > + return -EBUSY; > + case PSP_I2C_REQ_STS_INV_PARAM: > + default: > + return -EIO; > + }; > +} > + > +static int psp_send_check_i2c_req(struct psp_i2c_req *req) > +{ > + if (psp_send_cmd(req)) > + return -EIO; > + > + return check_i2c_req_sts(req); > +} > + > +static int psp_send_i2c_req(enum psp_i2c_req_type i2c_req_type) > +{ > + struct psp_i2c_req *req; > + unsigned long start; > + int status, ret; > + > + /* Allocate command-response buffer */ > + req = kzalloc(sizeof(*req), GFP_KERNEL); > + if (!req) > + return -ENOMEM; > + > + req->hdr.total_size = sizeof(*req); > + req->type = i2c_req_type; > + > + start = jiffies; > + ret = read_poll_timeout(psp_send_check_i2c_req, status, > + (status != -EBUSY), > + PSP_I2C_REQ_RETRY_DELAY_USEC, > + PSP_I2C_REQ_RETRY_CNT * PSP_I2C_REQ_RETRY_DELAY_USEC, > + 0, req); > + if (ret) > + goto cleanup; > + > + if (status) { > + ret = status; > + goto cleanup; > + } > + > + dev_dbg(psp_i2c_dev, "Request accepted by PSP after %ums\n", > + jiffies_to_msecs(jiffies - start)); > + > +cleanup: > + kfree(req); > + return ret; > +} > + > +static int psp_acquire_i2c_bus(void) > +{ > + int status; > + > + mutex_lock(&psp_i2c_access_mutex); > + > + /* Return early if mailbox malfunctioned */ > + if (psp_i2c_mbox_fail) > + goto cleanup; > + > + /* > + * Simply increment usage counter and return if PSP semaphore was > + * already taken by kernel. > + */ > + if (psp_i2c_access_count > 0) { > + psp_i2c_access_count++; > + goto cleanup; > + }; > + > + status = psp_send_i2c_req(PSP_I2C_REQ_ACQUIRE); > + if (status) { > + if (status == -ETIMEDOUT) > + dev_err(psp_i2c_dev, "Timed out waiting for PSP to release I2C bus\n"); > + else > + dev_err(psp_i2c_dev, "PSP communication error\n"); > + > + dev_err(psp_i2c_dev, "Assume i2c bus is for exclusive host usage\n"); > + psp_i2c_mbox_fail = true; > + goto cleanup; > + } > + > + psp_i2c_sem_acquired = jiffies; > + psp_i2c_access_count++; > + > +cleanup: > + mutex_unlock(&psp_i2c_access_mutex); > + return 0; > +} > + > +static void psp_release_i2c_bus(void) > +{ > + int status; > + > + mutex_lock(&psp_i2c_access_mutex); > + > + /* Return early if mailbox was malfunctional */ > + if (psp_i2c_mbox_fail) > + goto cleanup; > + > + /* > + * If we are last owner of PSP semaphore, need to release aribtration > + * via mailbox. > + */ > + psp_i2c_access_count--; > + if (psp_i2c_access_count > 0) > + goto cleanup; > + > + /* Send a release command to PSP */ > + status = psp_send_i2c_req(PSP_I2C_REQ_RELEASE); > + if (status) { > + if (status == -ETIMEDOUT) > + dev_err(psp_i2c_dev, "Timed out waiting for PSP to acquire I2C bus\n"); > + else > + dev_err(psp_i2c_dev, "PSP communication error\n"); > + > + dev_err(psp_i2c_dev, "Assume i2c bus is for exclusive host usage\n"); > + psp_i2c_mbox_fail = true; > + goto cleanup; > + } > + > + dev_dbg(psp_i2c_dev, "PSP semaphore held for %ums\n", > + jiffies_to_msecs(jiffies - psp_i2c_sem_acquired)); > + > +cleanup: > + mutex_unlock(&psp_i2c_access_mutex); > +} > + > +/* > + * Locking methods are based on the default implementation from > + * drivers/i2c/i2c-core-base.c, but with psp acquire and release operations > + * added. With this in place we can ensure that i2c clients on the bus shared > + * with psp are able to lock HW access to the bus for arbitrary number of > + * operations - that is e.g. write-wait-read. > + */ > +static void i2c_adapter_dw_psp_lock_bus(struct i2c_adapter *adapter, > + unsigned int flags) > +{ > + psp_acquire_i2c_bus(); > + rt_mutex_lock_nested(&adapter->bus_lock, i2c_adapter_depth(adapter)); > +} > + > +static int i2c_adapter_dw_psp_trylock_bus(struct i2c_adapter *adapter, > + unsigned int flags) > +{ > + int ret; > + > + ret = rt_mutex_trylock(&adapter->bus_lock); > + if (ret) > + return ret; > + > + psp_acquire_i2c_bus(); > + > + return ret; > +} > + > +static void i2c_adapter_dw_psp_unlock_bus(struct i2c_adapter *adapter, > + unsigned int flags) > +{ > + psp_release_i2c_bus(); > + rt_mutex_unlock(&adapter->bus_lock); > +} > + > +static const struct i2c_lock_operations i2c_dw_psp_lock_ops = { > + .lock_bus = i2c_adapter_dw_psp_lock_bus, > + .trylock_bus = i2c_adapter_dw_psp_trylock_bus, > + .unlock_bus = i2c_adapter_dw_psp_unlock_bus, > +}; > + > +int i2c_dw_amdpsp_probe_lock_support(struct dw_i2c_dev *dev) > +{ > + int ret; > + > + if (!dev || !dev->dev) > + return -ENODEV; > + > + if (!(dev->flags & ARBITRATION_SEMAPHORE)) > + return -ENODEV; > + > + /* Allow to bind only one instance of a driver */ > + if (psp_i2c_dev) > + return -EEXIST; > + > + psp_i2c_dev = dev->dev; > + > + ret = psp_mbox_probe(); > + if (ret) > + return ret; > + > + dev_info(psp_i2c_dev, "I2C bus managed by AMD PSP\n"); > + > + /* > + * Install global locking callbacks for adapter as well as internal i2c > + * controller locks. > + */ > + dev->adapter.lock_ops = &i2c_dw_psp_lock_ops; > + dev->acquire_lock = psp_acquire_i2c_bus; > + dev->release_lock = psp_release_i2c_bus; > + > + return 0; > +} > + > +/* Unmap area used as a mailbox with PSP */ > +void i2c_dw_amdpsp_remove_lock_support(struct dw_i2c_dev *dev) > +{ > + iounmap(mbox_iomem); > +} > diff --git a/drivers/i2c/busses/i2c-designware-baytrail.c b/drivers/i2c/busses/i2c-designware-baytrail.c > index c6a7a00e1d52..0c674542dd99 100644 > --- a/drivers/i2c/busses/i2c-designware-baytrail.c > +++ b/drivers/i2c/busses/i2c-designware-baytrail.c > @@ -12,25 +12,25 @@ > > #include "i2c-designware-core.h" > > -int i2c_dw_probe_lock_support(struct dw_i2c_dev *dev) > +int i2c_dw_baytrail_probe_lock_support(struct dw_i2c_dev *dev) > { > acpi_status status; > unsigned long long shared_host = 0; > acpi_handle handle; > > if (!dev || !dev->dev) > - return 0; > + return -ENODEV; > > handle = ACPI_HANDLE(dev->dev); > if (!handle) > - return 0; > + return -ENODEV; > > status = acpi_evaluate_integer(handle, "_SEM", NULL, &shared_host); > if (ACPI_FAILURE(status)) > - return 0; > + return -ENODEV; > > if (!shared_host) > - return 0; > + return -ENODEV; > > if (!iosf_mbi_available()) > return -EPROBE_DEFER; > diff --git a/drivers/i2c/busses/i2c-designware-core.h b/drivers/i2c/busses/i2c-designware-core.h > index 4b26cba40139..1d65212fddbd 100644 > --- a/drivers/i2c/busses/i2c-designware-core.h > +++ b/drivers/i2c/busses/i2c-designware-core.h > @@ -227,6 +227,8 @@ struct reset_control; > * @hs_lcnt: high speed LCNT value > * @acquire_lock: function to acquire a hardware lock on the bus > * @release_lock: function to release a hardware lock on the bus > + * @semaphore_idx: Index of table with semaphore type attached to the bus. It's > + * -1 if there is no semaphore. > * @shared_with_punit: true if this bus is shared with the SoCs PUNIT > * @disable: function to disable the controller > * @disable_int: function to disable all interrupts > @@ -285,6 +287,7 @@ struct dw_i2c_dev { > u16 hs_lcnt; > int (*acquire_lock)(void); > void (*release_lock)(void); > + int semaphore_idx; > bool shared_with_punit; > void (*disable)(struct dw_i2c_dev *dev); > void (*disable_int)(struct dw_i2c_dev *dev); > @@ -297,6 +300,7 @@ struct dw_i2c_dev { > > #define ACCESS_INTR_MASK BIT(0) > #define ACCESS_NO_IRQ_SUSPEND BIT(1) > +#define ARBITRATION_SEMAPHORE BIT(2) > > #define MODEL_MSCC_OCELOT BIT(8) > #define MODEL_BAIKAL_BT1 BIT(9) > @@ -310,6 +314,11 @@ struct dw_i2c_dev { > #define AMD_UCSI_INTR_REG 0x474 > #define AMD_UCSI_INTR_EN 0xd > > +struct i2c_dw_semaphore_callbacks { > + int (*probe)(struct dw_i2c_dev *dev); > + void (*remove)(struct dw_i2c_dev *dev); > +}; > + > int i2c_dw_init_regmap(struct dw_i2c_dev *dev); > u32 i2c_dw_scl_hcnt(u32 ic_clk, u32 tSYMBOL, u32 tf, int cond, int offset); > u32 i2c_dw_scl_lcnt(u32 ic_clk, u32 tLOW, u32 tf, int offset); > @@ -370,9 +379,12 @@ static inline void i2c_dw_configure(struct dw_i2c_dev *dev) > } > > #if IS_ENABLED(CONFIG_I2C_DESIGNWARE_BAYTRAIL) > -extern int i2c_dw_probe_lock_support(struct dw_i2c_dev *dev); > -#else > -static inline int i2c_dw_probe_lock_support(struct dw_i2c_dev *dev) { return 0; } > +int i2c_dw_baytrail_probe_lock_support(struct dw_i2c_dev *dev); > +#endif > + > +#if IS_ENABLED(CONFIG_I2C_DESIGNWARE_AMDPSP) > +int i2c_dw_amdpsp_probe_lock_support(struct dw_i2c_dev *dev); > +void i2c_dw_amdpsp_remove_lock_support(struct dw_i2c_dev *dev); > #endif > > int i2c_dw_validate_speed(struct dw_i2c_dev *dev); > diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c > index 2bd81abc86f6..7cb555d6c2e8 100644 > --- a/drivers/i2c/busses/i2c-designware-platdrv.c > +++ b/drivers/i2c/busses/i2c-designware-platdrv.c > @@ -50,6 +50,7 @@ static const struct acpi_device_id dw_i2c_acpi_match[] = { > { "808622C1", ACCESS_NO_IRQ_SUSPEND }, > { "AMD0010", ACCESS_INTR_MASK }, > { "AMDI0010", ACCESS_INTR_MASK }, > + { "AMDI0019", ACCESS_INTR_MASK | ARBITRATION_SEMAPHORE }, > { "AMDI0510", 0 }, > { "APMC0D0F", 0 }, > { "HISI02A1", 0 }, > @@ -204,6 +205,64 @@ static const struct dmi_system_id dw_i2c_hwmon_class_dmi[] = { > { } /* terminate list */ > }; > > +static const struct i2c_dw_semaphore_callbacks i2c_dw_semaphore_cb_table[] = { > +#ifdef CONFIG_I2C_DESIGNWARE_BAYTRAIL > + { > + .probe = i2c_dw_baytrail_probe_lock_support, > + }, > +#endif > +#ifdef CONFIG_I2C_DESIGNWARE_AMDPSP > + { > + .probe = i2c_dw_amdpsp_probe_lock_support, > + .remove = i2c_dw_amdpsp_remove_lock_support, > + }, > +#endif > + {} > +}; > + > +static int i2c_dw_probe_lock_support(struct dw_i2c_dev *dev) > +{ > + const struct i2c_dw_semaphore_callbacks *ptr; > + int i = 0; > + int ret; > + > + ptr = i2c_dw_semaphore_cb_table; > + > + dev->semaphore_idx = -1; > + > + while (ptr->probe) { > + ret = ptr->probe(dev); > + if (ret) { > + /* > + * If there is no semaphore device attached to this > + * controller, we shouldn't abort general i2c_controller > + * probe. > + */ > + if (ret == -ENODEV) { > + i++; > + ptr++; > + continue; > + } else { > + return ret; > + } > + } > + > + dev->semaphore_idx = i; > + break; > + } > + > + return 0; > +} > + > +static void i2c_dw_remove_lock_support(struct dw_i2c_dev *dev) > +{ > + if (dev->semaphore_idx < 0) > + return; > + > + if (i2c_dw_semaphore_cb_table[dev->semaphore_idx].remove) > + i2c_dw_semaphore_cb_table[dev->semaphore_idx].remove(dev); > +} > + > static int dw_i2c_plat_probe(struct platform_device *pdev) > { > struct i2c_adapter *adap; > @@ -334,6 +393,8 @@ static int dw_i2c_plat_remove(struct platform_device *pdev) > pm_runtime_put_sync(&pdev->dev); > dw_i2c_plat_pm_cleanup(dev); > > + i2c_dw_remove_lock_support(dev); > + > reset_control_assert(dev->rst); > > return 0; > -- > 2.35.0.rc0.227.g00780c9af4-goog >
On Fri, Jan 28, 2022 at 03:59:40PM +0100, Jan Dąbroś wrote: > Hi, > > Adding proper Andy's email address (and removing wrong one) in the > whole patchset. Sorry for noise! Thanks! > pt., 28 sty 2022 o 15:48 Jan Dabros <jsd@semihalf.com> napisał(a): > > > > Implement an I2C controller sharing mechanism between the host (kernel) > > and PSP co-processor on some platforms equipped with AMD Cezanne SoC. > > > > On these platforms we need to implement "software" i2c arbitration. > > Default arbitration owner is PSP and kernel asks for acquire as well > > as inform about release of the i2c bus via mailbox mechanism. > > > > +---------+ > > <- ACQUIRE | | > > +---------| CPU |\ > > | | | \ +----------+ SDA > > | +---------+ \ | |------- > > MAILBOX +--> | I2C-DW | SCL > > | +---------+ | |------- > > | | | +----------+ > > +---------| PSP | > > <- ACK | | > > +---------+ > > > > +---------+ > > <- RELEASE | | > > +---------| CPU | > > | | | +----------+ SDA > > | +---------+ | |------- > > MAILBOX +--> | I2C-DW | SCL > > | +---------+ / | |------- > > | | | / +----------+ > > +---------| PSP |/ > > <- ACK | | > > +---------+ > > > > The solution is similar to i2c-designware-baytrail.c implementation, where > > we are using a generic i2c-designware-* driver with a small "wrapper". > > > > In contrary to baytrail semaphore implementation, beside internal > > acquire_lock() and release_lock() methods we are also applying quirks to > > lock_bus() and unlock_bus() global adapter methods. With this in place > > all i2c clients drivers may lock i2c bus for a desired number of i2c > > transactions (e.g. write-wait-read) without being aware of that such bus > > is shared with another entity. > > > > Modify i2c_dw_probe_lock_support() to select correct semaphore > > implementation at runtime, since now we have more than one available. > > > > Configure new matching ACPI ID "AMDI0019" and register > > ARBITRATION_SEMAPHORE flag in order to distinguish setup with PSP > > arbitration. > > > > Add myself as a reviewer for I2C DesignWare in order to help with reviewing > > and testing possible changes touching new i2c-designware-amdpsp.c module. > > > > Signed-off-by: Jan Dabros <jsd@semihalf.com> > > Reported-by: kernel test robot <lkp@intel.com> > > Reported-by: kernel test robot <lkp@intel.com> New feature can't be reported. If you want to give a credit to CI, do it in changelog. ... > > + depends on X86_64 Not sure if it's better than using non-atomic IO helpers. At least you can't run 32-bit kernels on that platforms in order to get this functionality working. Doest it mean those platforms do not have 32-bit compatibility mode anymore? ... > > +#include <linux/io-64-nonatomic-lo-hi.h> Ah, this is not needed if you keep code running exclusively on 64-bit platforms. ... > > +struct psp_mbox { > > + u32 cmd_fields; > > + phys_addr_t i2c_req_addr; But phys_addr_t is platform-dependent type. Perhaps you meant to use u64 here always? > > +} __packed; ... > > + struct psp_mbox __iomem *mbox = (struct psp_mbox __iomem *)mbox_iomem; For void * pointers the cast is implied, i.o.w. it's not needed here. ... > > +static int psp_send_check_i2c_req(struct psp_i2c_req *req) > > +{ > > + if (psp_send_cmd(req)) > > + return -EIO; Why is error code shadowed? > > + return check_i2c_req_sts(req); > > +} ... > > +cleanup: > > + mutex_unlock(&psp_i2c_access_mutex); > > + return 0; Not sure I understand why we ignore all above errors here. ... > > + if (!dev || !dev->dev) > > + return -ENODEV; At which circumstances may we get dev != NULL dev->dev == NULL ? ... > > if (!dev || !dev->dev) > > - return 0; > > + return -ENODEV; I see the same here, perhaps Hans knows the answer :-) ... > > +static int i2c_dw_probe_lock_support(struct dw_i2c_dev *dev) > > +{ > > + const struct i2c_dw_semaphore_callbacks *ptr; > > + int i = 0; > > + int ret; > > + > > + ptr = i2c_dw_semaphore_cb_table; > > + > > + dev->semaphore_idx = -1; > > + > > + while (ptr->probe) { > > + ret = ptr->probe(dev); > > + if (ret) { > > + /* > > + * If there is no semaphore device attached to this > > + * controller, we shouldn't abort general i2c_controller > > + * probe. > > + */ > > + if (ret == -ENODEV) { > > + i++; > > + ptr++; > > + continue; > > + } else { Redundant 'else', but see below. > > + return ret; > > + } May it be if (ret != -ENODEV) return ret; i++; ptr++; continue; ? > > + } > > + > > + dev->semaphore_idx = i; > > + break; > > + } > > + > > + return 0; > > +}
Aargh.. so if this won't be enough to use wrong email address in v2 - I not used plain text above. Mailing list (understandably) aren't happy with this, thus resending my answers to Andy.. Again sorry for noise. pt., 28 sty 2022 o 16:50 Andy Shevchenko <andriy.shevchenko@linux.intel.com> napisał(a): > > On Fri, Jan 28, 2022 at 03:59:40PM +0100, Jan Dąbroś wrote: > > Hi, > > > > Adding proper Andy's email address (and removing wrong one) in the > > whole patchset. Sorry for noise! > > Thanks! > > > pt., 28 sty 2022 o 15:48 Jan Dabros <jsd@semihalf.com> napisał(a): > > > > > > Implement an I2C controller sharing mechanism between the host (kernel) > > > and PSP co-processor on some platforms equipped with AMD Cezanne SoC. > > > > > > On these platforms we need to implement "software" i2c arbitration. > > > Default arbitration owner is PSP and kernel asks for acquire as well > > > as inform about release of the i2c bus via mailbox mechanism. > > > > > > +---------+ > > > <- ACQUIRE | | > > > +---------| CPU |\ > > > | | | \ +----------+ SDA > > > | +---------+ \ | |------- > > > MAILBOX +--> | I2C-DW | SCL > > > | +---------+ | |------- > > > | | | +----------+ > > > +---------| PSP | > > > <- ACK | | > > > +---------+ > > > > > > +---------+ > > > <- RELEASE | | > > > +---------| CPU | > > > | | | +----------+ SDA > > > | +---------+ | |------- > > > MAILBOX +--> | I2C-DW | SCL > > > | +---------+ / | |------- > > > | | | / +----------+ > > > +---------| PSP |/ > > > <- ACK | | > > > +---------+ > > > > > > The solution is similar to i2c-designware-baytrail.c implementation, where > > > we are using a generic i2c-designware-* driver with a small "wrapper". > > > > > > In contrary to baytrail semaphore implementation, beside internal > > > acquire_lock() and release_lock() methods we are also applying quirks to > > > lock_bus() and unlock_bus() global adapter methods. With this in place > > > all i2c clients drivers may lock i2c bus for a desired number of i2c > > > transactions (e.g. write-wait-read) without being aware of that such bus > > > is shared with another entity. > > > > > > Modify i2c_dw_probe_lock_support() to select correct semaphore > > > implementation at runtime, since now we have more than one available. > > > > > > Configure new matching ACPI ID "AMDI0019" and register > > > ARBITRATION_SEMAPHORE flag in order to distinguish setup with PSP > > > arbitration. > > > > > > Add myself as a reviewer for I2C DesignWare in order to help with reviewing > > > and testing possible changes touching new i2c-designware-amdpsp.c module. > > > > > > Signed-off-by: Jan Dabros <jsd@semihalf.com> > > > > Reported-by: kernel test robot <lkp@intel.com> > > > Reported-by: kernel test robot <lkp@intel.com> > > New feature can't be reported. > If you want to give a credit to CI, do it in changelog. OK, will remove this. > ... > > > > + depends on X86_64 > > Not sure if it's better than using non-atomic IO helpers. There are 2 issues reported by kernel robot for my patchset: 1. Lack of <asm/msr.h>; 2. Missing declaration for 'writeq'. Actually above was my idea to fix first issue, but please see below. > At least you can't run 32-bit kernels on that platforms > in order to get this functionality working. Doest it mean > those platforms do not have 32-bit compatibility mode > anymore? Correct, I was focusing too much on my use case, where I'm building only 64-bit. This isn't right. Furthermore I should rather use dependency on CONFIG_X86_MSR which is better suited for ensuring above msr.h header is present. > > ... > > > > +#include <linux/io-64-nonatomic-lo-hi.h> > > Ah, this is not needed if you keep code running exclusively on 64-bit > platforms. Will keep this, since switching to "depends on X86_MSR". > ... > > > > +struct psp_mbox { > > > + u32 cmd_fields; > > > > + phys_addr_t i2c_req_addr; > > But phys_addr_t is platform-dependent type. Perhaps you meant to use u64 here > always? Once I remove the "depends on X86_64" I believe this should be left platform-dependent. > > > +} __packed; > > ... > > > > + struct psp_mbox __iomem *mbox = (struct psp_mbox __iomem *)mbox_iomem; > > For void * pointers the cast is implied, i.o.w. it's not needed here. ACK. > ... > > > > +static int psp_send_check_i2c_req(struct psp_i2c_req *req) > > > +{ > > > + if (psp_send_cmd(req)) > > > > + return -EIO; > > Why is error code shadowed? > > > > + return check_i2c_req_sts(req); > > > +} Just as a side note - it wasn't modified in v2 when moving above to psp_send_check_i2c_req(), but let me explain why I have introduced this initially. We have two means of timeouts in the context of this driver: 1. Timeout of internal mailbox, which means we cannot communicate with a PSP for a programmed timeout. This timeout is encountered inside psp_send_cmd(). 2. Timeout of i2c arbitration - which means that we can communicate with PSP, but PSP refuses to release i2c bus for too long. This timeout is returned by psp_send_i2c_req() in case of error. (side note: both error conditions are very unlikely to happen at runtime) I wanted to clearly distinguish between these two and thus put all errors around mailbox into "-EIO category", which is actually true. > ... > > > > +cleanup: > > > + mutex_unlock(&psp_i2c_access_mutex); > > > + return 0; > > Not sure I understand why we ignore all above errors here. Actually we are not ignoring them, since each error sets "psp_i2c_mbox_fail = true;". This means that if there is any error on x86-PSP interface, we are ignoring i2c-arbitration and just fall back to normal (that is no-quirk) operation.
On Mon, Jan 31, 2022 at 12:56:27PM +0100, Jan Dąbroś wrote: > pt., 28 sty 2022 o 16:50 Andy Shevchenko <andriy.shevchenko@linux.intel.com> > napisał(a): > > On Fri, Jan 28, 2022 at 03:59:40PM +0100, Jan Dąbroś wrote: > > > pt., 28 sty 2022 o 15:48 Jan Dabros <jsd@semihalf.com> napisał(a): ... > > > > +struct psp_mbox { > > > > + u32 cmd_fields; > > > > > > + phys_addr_t i2c_req_addr; > > > > But phys_addr_t is platform-dependent type. Perhaps you meant to use u64 > > here > > always? > > Once I remove the "depends on X86_64" I believe this should be left > platform-dependent. If it's a protocol or HW layout, it may not be platform-dependent. > > > > +} __packed; ... > > > > + if (psp_send_cmd(req)) > > > > > > + return -EIO; > > > > Why is error code shadowed? > > > > Just as a side note - it wasn't modified in v2 when moving above to > psp_send_check_i2c_req(), but let me explain why I have introduced this > initially. > > We have two means of timeouts in the context of this driver: > 1. Timeout of internal mailbox, which means we cannot communicate with a > PSP for a programmed timeout. This timeout is encountered inside > psp_send_cmd(). > 2. Timeout of i2c arbitration - which means that we can communicate with > PSP, but PSP refuses to release i2c bus for too long. This timeout is > returned by psp_send_i2c_req() in case of error. > (side note: both error conditions are very unlikely to happen at runtime) > > I wanted to clearly distinguish between these two and thus put all errors > around mailbox into "-EIO category", which is actually true. At very least this code needs more or less the above to be put as a comment. ... > > > > +cleanup: > > > > + mutex_unlock(&psp_i2c_access_mutex); > > > > + return 0; > > > > Not sure I understand why we ignore all above errors here. > > > > Actually we are not ignoring them, since each error sets "psp_i2c_mbox_fail > = true;". This means that if there is any error on x86-PSP interface, we > are ignoring i2c-arbitration and just fall back to normal (that is > no-quirk) operation. > > From the i2c-client perspective (who is eventually gathering error code > from above) I think we can claim that everything is fine, since bus is > granted to it. For developers there is an error message in case some debug > will be necessary. Perhaps needs a comment (sorry, if I overlooked it). ... > > > > + if (!dev || !dev->dev) > > > > + return -ENODEV; > > > > At which circumstances may we get > > dev != NULL > > dev->dev == NULL > > ? > > > > ... > > > > > > if (!dev || !dev->dev) > > > > - return 0; > > > > + return -ENODEV; > > > > I see the same here, perhaps Hans knows the answer :-) > > Right, so I must admit that I simply used *-baytrail.c as a reference and > thinking that additional check shouldn't hurt us (always better than not > enough safety..). Looking more at this now - `dw_i2c_plat_probe()` will > boil-out earlier if `dev->dev == NULL`. Should I remove this extra check in > *-baytrail.c in the same commit? Maybe. Please, double check that it's not needed indeed.
pon., 31 sty 2022 o 14:32 Andy Shevchenko <andriy.shevchenko@linux.intel.com> napisał(a): > > On Mon, Jan 31, 2022 at 12:56:27PM +0100, Jan Dąbroś wrote: > > pt., 28 sty 2022 o 16:50 Andy Shevchenko <andriy.shevchenko@linux.intel.com> > > napisał(a): > > > On Fri, Jan 28, 2022 at 03:59:40PM +0100, Jan Dąbroś wrote: > > > > pt., 28 sty 2022 o 15:48 Jan Dabros <jsd@semihalf.com> napisał(a): > > ... > > > > > > +struct psp_mbox { > > > > > + u32 cmd_fields; > > > > > > > > + phys_addr_t i2c_req_addr; > > > > > > But phys_addr_t is platform-dependent type. Perhaps you meant to use u64 > > > here > > > always? > > > > Once I remove the "depends on X86_64" I believe this should be left > > platform-dependent. > > If it's a protocol or HW layout, it may not be platform-dependent. Right you are correct, will keep this as 64bit variable. > > > > > > +} __packed; > > ... > > > > > > + if (psp_send_cmd(req)) > > > > > > > > + return -EIO; > > > > > > Why is error code shadowed? > > > > > > > Just as a side note - it wasn't modified in v2 when moving above to > > psp_send_check_i2c_req(), but let me explain why I have introduced this > > initially. > > > > We have two means of timeouts in the context of this driver: > > 1. Timeout of internal mailbox, which means we cannot communicate with a > > PSP for a programmed timeout. This timeout is encountered inside > > psp_send_cmd(). > > 2. Timeout of i2c arbitration - which means that we can communicate with > > PSP, but PSP refuses to release i2c bus for too long. This timeout is > > returned by psp_send_i2c_req() in case of error. > > (side note: both error conditions are very unlikely to happen at runtime) > > > > I wanted to clearly distinguish between these two and thus put all errors > > around mailbox into "-EIO category", which is actually true. > > At very least this code needs more or less the above to be put as a comment. ACK > > ... > > > > > > +cleanup: > > > > > + mutex_unlock(&psp_i2c_access_mutex); > > > > > + return 0; > > > > > > Not sure I understand why we ignore all above errors here. > > > > > > > Actually we are not ignoring them, since each error sets "psp_i2c_mbox_fail > > = true;". This means that if there is any error on x86-PSP interface, we > > are ignoring i2c-arbitration and just fall back to normal (that is > > no-quirk) operation. > > > > From the i2c-client perspective (who is eventually gathering error code > > from above) I think we can claim that everything is fine, since bus is > > granted to it. For developers there is an error message in case some debug > > will be necessary. > > Perhaps needs a comment (sorry, if I overlooked it). ACK. > > ... > > > > > > + if (!dev || !dev->dev) > > > > > + return -ENODEV; > > > > > > At which circumstances may we get > > > dev != NULL > > > dev->dev == NULL > > > ? > > > > > > ... > > > > > > > > if (!dev || !dev->dev) > > > > > - return 0; > > > > > + return -ENODEV; > > > > > > I see the same here, perhaps Hans knows the answer :-) > > > > Right, so I must admit that I simply used *-baytrail.c as a reference and > > thinking that additional check shouldn't hurt us (always better than not > > enough safety..). Looking more at this now - `dw_i2c_plat_probe()` will > > boil-out earlier if `dev->dev == NULL`. Should I remove this extra check in > > *-baytrail.c in the same commit? > > Maybe. Please, double check that it's not needed indeed. Confirmed that this is unnecessary. Best Regards, Jan > > -- > With Best Regards, > Andy Shevchenko > >
On 2/2/2022 08:43, Jan Dabros wrote: > Implement an I2C controller sharing mechanism between the host (kernel) > and PSP co-processor on some platforms equipped with AMD Cezanne SoC. > > On these platforms we need to implement "software" i2c arbitration. > Default arbitration owner is PSP and kernel asks for acquire as well > as inform about release of the i2c bus via mailbox mechanism. > > +---------+ > <- ACQUIRE | | > +---------| CPU |\ > | | | \ +----------+ SDA > | +---------+ \ | |------- > MAILBOX +--> | I2C-DW | SCL > | +---------+ | |------- > | | | +----------+ > +---------| PSP | > <- ACK | | > +---------+ > > +---------+ > <- RELEASE | | > +---------| CPU | > | | | +----------+ SDA > | +---------+ | |------- > MAILBOX +--> | I2C-DW | SCL > | +---------+ / | |------- > | | | / +----------+ > +---------| PSP |/ > <- ACK | | > +---------+ > > The solution is similar to i2c-designware-baytrail.c implementation, where > we are using a generic i2c-designware-* driver with a small "wrapper". > > In contrary to baytrail semaphore implementation, beside internal > acquire_lock() and release_lock() methods we are also applying quirks to > lock_bus() and unlock_bus() global adapter methods. With this in place > all i2c clients drivers may lock i2c bus for a desired number of i2c > transactions (e.g. write-wait-read) without being aware of that such bus > is shared with another entity. > > Modify i2c_dw_probe_lock_support() to select correct semaphore > implementation at runtime, since now we have more than one available. > > Configure new matching ACPI ID "AMDI0019" and register > ARBITRATION_SEMAPHORE flag in order to distinguish setup with PSP > arbitration. > > Add myself as a reviewer for I2C DesignWare in order to help with reviewing > and testing possible changes touching new i2c-designware-amdpsp.c module. > > Signed-off-by: Jan Dabros <jsd@semihalf.com> > Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> > --- > MAINTAINERS | 1 + > drivers/acpi/acpi_apd.c | 7 +- > drivers/i2c/busses/Kconfig | 11 + > drivers/i2c/busses/Makefile | 1 + > drivers/i2c/busses/i2c-designware-amdpsp.c | 389 +++++++++++++++++++ > drivers/i2c/busses/i2c-designware-baytrail.c | 12 +- > drivers/i2c/busses/i2c-designware-core.h | 18 +- > drivers/i2c/busses/i2c-designware-platdrv.c | 60 +++ > 8 files changed, 487 insertions(+), 12 deletions(-) > create mode 100644 drivers/i2c/busses/i2c-designware-amdpsp.c > > diff --git a/MAINTAINERS b/MAINTAINERS > index f41088418aae..e0a7e05c5a41 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -18666,6 +18666,7 @@ SYNOPSYS DESIGNWARE I2C DRIVER > M: Jarkko Nikula <jarkko.nikula@linux.intel.com> > R: Andy Shevchenko <andriy.shevchenko@linux.intel.com> > R: Mika Westerberg <mika.westerberg@linux.intel.com> > +R: Jan Dabros <jsd@semihalf.com> > L: linux-i2c@vger.kernel.org > S: Maintained > F: drivers/i2c/busses/i2c-designware-* > diff --git a/drivers/acpi/acpi_apd.c b/drivers/acpi/acpi_apd.c > index e7934ba79b02..ad245bbd965e 100644 > --- a/drivers/acpi/acpi_apd.c > +++ b/drivers/acpi/acpi_apd.c > @@ -232,12 +232,13 @@ static const struct acpi_device_id acpi_apd_device_ids[] = { > /* Generic apd devices */ > #ifdef CONFIG_X86_AMD_PLATFORM_DEVICE > { "AMD0010", APD_ADDR(cz_i2c_desc) }, > - { "AMDI0010", APD_ADDR(wt_i2c_desc) }, > { "AMD0020", APD_ADDR(cz_uart_desc) }, > - { "AMDI0020", APD_ADDR(cz_uart_desc) }, > - { "AMDI0022", APD_ADDR(cz_uart_desc) }, > { "AMD0030", }, > { "AMD0040", APD_ADDR(fch_misc_desc)}, > + { "AMDI0010", APD_ADDR(wt_i2c_desc) }, > + { "AMDI0019", APD_ADDR(wt_i2c_desc) }, Did you already check with anyone in AMD about reserving this ID? Considering this design is specific to arbitration used for Chromebooks I wonder if it is better to be GOOG ID? I can see it both ways, but if you didn't already talk to anyone and the consensus is for it to be AMDI****, I will ask around internally about reserving it / making sure there are no future or existing conflicts. > + { "AMDI0020", APD_ADDR(cz_uart_desc) }, > + { "AMDI0022", APD_ADDR(cz_uart_desc) }, > { "HYGO0010", APD_ADDR(wt_i2c_desc) }, > #endif > #ifdef CONFIG_ARM64 > diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig > index 42da31c1ab70..5ea26a7aa1d5 100644 > --- a/drivers/i2c/busses/Kconfig > +++ b/drivers/i2c/busses/Kconfig > @@ -553,6 +553,17 @@ config I2C_DESIGNWARE_PLATFORM > This driver can also be built as a module. If so, the module > will be called i2c-designware-platform. > > +config I2C_DESIGNWARE_AMDPSP > + bool "AMD PSP I2C semaphore support" > + depends on X86_MSR > + depends on ACPI > + depends on I2C_DESIGNWARE_PLATFORM > + help > + This driver enables managed host access to the selected I2C bus shared > + between AMD CPU and AMD PSP. > + > + You should say Y if running on an AMD system equipped with the PSP. > + > config I2C_DESIGNWARE_BAYTRAIL > bool "Intel Baytrail I2C semaphore support" > depends on ACPI > diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile > index 1d00dce77098..752f47be3fc1 100644 > --- a/drivers/i2c/busses/Makefile > +++ b/drivers/i2c/busses/Makefile > @@ -54,6 +54,7 @@ i2c-designware-core-y += i2c-designware-master.o > i2c-designware-core-$(CONFIG_I2C_DESIGNWARE_SLAVE) += i2c-designware-slave.o > obj-$(CONFIG_I2C_DESIGNWARE_PLATFORM) += i2c-designware-platform.o > i2c-designware-platform-y := i2c-designware-platdrv.o > +i2c-designware-platform-$(CONFIG_I2C_DESIGNWARE_AMDPSP) += i2c-designware-amdpsp.o > i2c-designware-platform-$(CONFIG_I2C_DESIGNWARE_BAYTRAIL) += i2c-designware-baytrail.o > obj-$(CONFIG_I2C_DESIGNWARE_PCI) += i2c-designware-pci.o > i2c-designware-pci-y := i2c-designware-pcidrv.o > diff --git a/drivers/i2c/busses/i2c-designware-amdpsp.c b/drivers/i2c/busses/i2c-designware-amdpsp.c > new file mode 100644 > index 000000000000..a45e4faeb2c1 > --- /dev/null > +++ b/drivers/i2c/busses/i2c-designware-amdpsp.c > @@ -0,0 +1,389 @@ > +// SPDX-License-Identifier: GPL-2.0 > + > +#include <linux/bitfield.h> > +#include <linux/i2c.h> > +#include <linux/io-64-nonatomic-lo-hi.h> > +#include <linux/psp-sev.h> > +#include <linux/types.h> > + > +#include <asm/msr.h> > + > +#include "i2c-designware-core.h" > + > +#define MSR_AMD_PSP_ADDR 0xc00110a2 > +#define PSP_MBOX_OFFSET 0x10570 > +#define PSP_CMD_TIMEOUT_MS 500 > + > +#define PSP_I2C_REQ_BUS_CMD 0x64 > +#define PSP_I2C_REQ_RETRY_CNT 10 > +#define PSP_I2C_REQ_RETRY_DELAY_USEC (50 * 1000) > +#define PSP_I2C_REQ_STS_OK 0x0 > +#define PSP_I2C_REQ_STS_BUS_BUSY 0x1 > +#define PSP_I2C_REQ_STS_INV_PARAM 0x3 > + > +#define PSP_MBOX_FIELDS_STS GENMASK(15, 0) > +#define PSP_MBOX_FIELDS_CMD GENMASK(23, 16) > +#define PSP_MBOX_FIELDS_RESERVED GENMASK(29, 24) > +#define PSP_MBOX_FIELDS_RECOVERY BIT(30) > +#define PSP_MBOX_FIELDS_READY BIT(31) > + > +struct psp_req_buffer_hdr { > + u32 total_size; > + u32 status; > +}; > + > +enum psp_i2c_req_type { > + PSP_I2C_REQ_ACQUIRE, > + PSP_I2C_REQ_RELEASE, > + PSP_I2C_REQ_MAX > +}; > + > +struct psp_i2c_req { > + struct psp_req_buffer_hdr hdr; > + enum psp_i2c_req_type type; > +} __aligned(32); > + > +struct psp_mbox { > + u32 cmd_fields; > + u64 i2c_req_addr; > +} __packed; > + > +static DEFINE_MUTEX(psp_i2c_access_mutex); > +static unsigned long psp_i2c_sem_acquired; > +static void __iomem *mbox_iomem; > +static u32 psp_i2c_access_count; > +static bool psp_i2c_mbox_fail; > +static struct device *psp_i2c_dev; > + > +/* > + * Implementation of PSP-x86 i2c-arbitration mailbox introduced for AMD Cezanne > + * family of SoCs. > + */ > + > +static int psp_get_mbox_addr(unsigned long *mbox_addr) > +{ > + unsigned long long psp_mmio; > + > + if (rdmsrl_safe(MSR_AMD_PSP_ADDR, &psp_mmio)) > + return -EIO; > + > + *mbox_addr = (unsigned long)(psp_mmio + PSP_MBOX_OFFSET); > + > + return 0; > +} > + > +static int psp_mbox_probe(void) > +{ > + unsigned long mbox_addr; > + int ret; > + > + ret = psp_get_mbox_addr(&mbox_addr); > + if (ret) > + return ret; > + > + mbox_iomem = ioremap(mbox_addr, sizeof(struct psp_mbox)); > + if (!mbox_iomem) > + return -ENOMEM; > + > + return 0; > +} > + > + > +/* Recovery field should be equal 0 to start sending commands */ > +static int psp_check_mbox_recovery(struct psp_mbox __iomem *mbox) > +{ > + u32 tmp; > + > + tmp = readl(&mbox->cmd_fields); > + > + return FIELD_GET(PSP_MBOX_FIELDS_RECOVERY, tmp); > +} > + > +static int psp_wait_cmd(struct psp_mbox __iomem *mbox) > +{ > + u32 tmp, expected; > + > + /* Expect mbox_cmd to be cleared and ready bit to be set by PSP */ > + expected = FIELD_PREP(PSP_MBOX_FIELDS_READY, 1); > + > + return readl_poll_timeout(&mbox->cmd_fields, tmp, (tmp == expected), > + 0, 1000 * PSP_CMD_TIMEOUT_MS); > +} > + > +/* Status equal to 0 means that PSP succeed processing command */ > +static int psp_check_mbox_sts(struct psp_mbox __iomem *mbox) > +{ > + u32 cmd_reg; > + > + cmd_reg = readl(&mbox->cmd_fields); > + > + return FIELD_GET(PSP_MBOX_FIELDS_STS, cmd_reg); > +} > + > +static int psp_send_cmd(struct psp_i2c_req *req) > +{ > + struct psp_mbox __iomem *mbox = mbox_iomem; > + phys_addr_t req_addr; > + u32 cmd_reg; > + > + if (psp_check_mbox_recovery(mbox)) > + return -EIO; > + > + if (psp_wait_cmd(mbox)) > + return -EBUSY; > + > + /* > + * Fill mailbox with address of command-response buffer, which will be > + * used for sending i2c requests as well as reading status returned by > + * PSP. Use physical address of buffer, since PSP will map this region. > + */ > + req_addr = __psp_pa((void *)req); > + writeq(req_addr, &mbox->i2c_req_addr); > + > + /* Write command register to trigger processing */ > + cmd_reg = FIELD_PREP(PSP_MBOX_FIELDS_CMD, PSP_I2C_REQ_BUS_CMD); > + writel(cmd_reg, &mbox->cmd_fields); > + > + if (psp_wait_cmd(mbox)) > + return -ETIMEDOUT; > + > + if (psp_check_mbox_sts(mbox)) > + return -EIO; > + > + return 0; > +} > + > +/* Helper to verify status returned by PSP */ > +static int check_i2c_req_sts(struct psp_i2c_req *req) > +{ > + int status; > + > + status = readl(&req->hdr.status); > + > + switch (status) { > + case PSP_I2C_REQ_STS_OK: > + return 0; > + case PSP_I2C_REQ_STS_BUS_BUSY: > + return -EBUSY; > + case PSP_I2C_REQ_STS_INV_PARAM: > + default: > + return -EIO; > + }; > +} > + > +static int psp_send_check_i2c_req(struct psp_i2c_req *req) > +{ > + /* > + * Errors in x86-PSP i2c-arbitration protocol may occur at two levels: > + * 1. mailbox communication - PSP is not operational or some IO errors > + * with basic communication had happened; > + * 2. i2c-requests - PSP refuses to grant i2c arbitration to x86 for too > + * long. > + * In order to distinguish between these two in error handling code, all > + * errors on the first level (returned by psp_send_cmd) are shadowed by > + * -EIO. > + */ > + if (psp_send_cmd(req)) > + return -EIO; > + > + return check_i2c_req_sts(req); > +} > + > +static int psp_send_i2c_req(enum psp_i2c_req_type i2c_req_type) > +{ > + struct psp_i2c_req *req; > + unsigned long start; > + int status, ret; > + > + /* Allocate command-response buffer */ > + req = kzalloc(sizeof(*req), GFP_KERNEL); > + if (!req) > + return -ENOMEM; > + > + req->hdr.total_size = sizeof(*req); > + req->type = i2c_req_type; > + > + start = jiffies; > + ret = read_poll_timeout(psp_send_check_i2c_req, status, > + (status != -EBUSY), > + PSP_I2C_REQ_RETRY_DELAY_USEC, > + PSP_I2C_REQ_RETRY_CNT * PSP_I2C_REQ_RETRY_DELAY_USEC, > + 0, req); > + if (ret) > + goto cleanup; > + > + if (status) { > + ret = status; > + goto cleanup; > + } > + > + dev_dbg(psp_i2c_dev, "Request accepted by PSP after %ums\n", > + jiffies_to_msecs(jiffies - start)); > + > +cleanup: > + kfree(req); > + return ret; > +} > + > +static int psp_acquire_i2c_bus(void) > +{ > + int status; > + > + mutex_lock(&psp_i2c_access_mutex); > + > + /* Return early if mailbox malfunctioned */ > + if (psp_i2c_mbox_fail) > + goto cleanup; > + > + /* > + * Simply increment usage counter and return if PSP semaphore was > + * already taken by kernel. > + */ > + if (psp_i2c_access_count > 0) { > + psp_i2c_access_count++; > + goto cleanup; > + }; > + > + status = psp_send_i2c_req(PSP_I2C_REQ_ACQUIRE); > + if (status) { > + if (status == -ETIMEDOUT) > + dev_err(psp_i2c_dev, "Timed out waiting for PSP to release I2C bus\n"); > + else > + dev_err(psp_i2c_dev, "PSP communication error\n"); > + > + dev_err(psp_i2c_dev, "Assume i2c bus is for exclusive host usage\n"); > + psp_i2c_mbox_fail = true; > + goto cleanup; > + } > + > + psp_i2c_sem_acquired = jiffies; > + psp_i2c_access_count++; > + > + /* > + * In case of errors with PSP arbitrator psp_i2c_mbox_fail variable is > + * set above. As a consequence consecutive calls to acquire will bypass > + * communication with PSP. At any case i2c bus is granted to the caller, > + * thus always return success. > + */ > +cleanup: > + mutex_unlock(&psp_i2c_access_mutex); > + return 0; > +} > + > +static void psp_release_i2c_bus(void) > +{ > + int status; > + > + mutex_lock(&psp_i2c_access_mutex); > + > + /* Return early if mailbox was malfunctional */ > + if (psp_i2c_mbox_fail) > + goto cleanup; > + > + /* > + * If we are last owner of PSP semaphore, need to release aribtration > + * via mailbox. > + */ > + psp_i2c_access_count--; > + if (psp_i2c_access_count > 0) > + goto cleanup; > + > + /* Send a release command to PSP */ > + status = psp_send_i2c_req(PSP_I2C_REQ_RELEASE); > + if (status) { > + if (status == -ETIMEDOUT) > + dev_err(psp_i2c_dev, "Timed out waiting for PSP to acquire I2C bus\n"); > + else > + dev_err(psp_i2c_dev, "PSP communication error\n"); > + > + dev_err(psp_i2c_dev, "Assume i2c bus is for exclusive host usage\n"); > + psp_i2c_mbox_fail = true; > + goto cleanup; > + } > + > + dev_dbg(psp_i2c_dev, "PSP semaphore held for %ums\n", > + jiffies_to_msecs(jiffies - psp_i2c_sem_acquired)); > + > +cleanup: > + mutex_unlock(&psp_i2c_access_mutex); > +} > + > +/* > + * Locking methods are based on the default implementation from > + * drivers/i2c/i2c-core-base.c, but with psp acquire and release operations > + * added. With this in place we can ensure that i2c clients on the bus shared > + * with psp are able to lock HW access to the bus for arbitrary number of > + * operations - that is e.g. write-wait-read. > + */ > +static void i2c_adapter_dw_psp_lock_bus(struct i2c_adapter *adapter, > + unsigned int flags) > +{ > + psp_acquire_i2c_bus(); > + rt_mutex_lock_nested(&adapter->bus_lock, i2c_adapter_depth(adapter)); > +} > + > +static int i2c_adapter_dw_psp_trylock_bus(struct i2c_adapter *adapter, > + unsigned int flags) > +{ > + int ret; > + > + ret = rt_mutex_trylock(&adapter->bus_lock); > + if (ret) > + return ret; > + > + psp_acquire_i2c_bus(); > + > + return ret; > +} > + > +static void i2c_adapter_dw_psp_unlock_bus(struct i2c_adapter *adapter, > + unsigned int flags) > +{ > + psp_release_i2c_bus(); > + rt_mutex_unlock(&adapter->bus_lock); > +} > + > +static const struct i2c_lock_operations i2c_dw_psp_lock_ops = { > + .lock_bus = i2c_adapter_dw_psp_lock_bus, > + .trylock_bus = i2c_adapter_dw_psp_trylock_bus, > + .unlock_bus = i2c_adapter_dw_psp_unlock_bus, > +}; > + > +int i2c_dw_amdpsp_probe_lock_support(struct dw_i2c_dev *dev) > +{ > + int ret; > + > + if (!dev) > + return -ENODEV; > + > + if (!(dev->flags & ARBITRATION_SEMAPHORE)) > + return -ENODEV; > + > + /* Allow to bind only one instance of a driver */ > + if (psp_i2c_dev) > + return -EEXIST; > + > + psp_i2c_dev = dev->dev; > + > + ret = psp_mbox_probe(); > + if (ret) > + return ret; > + > + dev_info(psp_i2c_dev, "I2C bus managed by AMD PSP\n"); > + > + /* > + * Install global locking callbacks for adapter as well as internal i2c > + * controller locks. > + */ > + dev->adapter.lock_ops = &i2c_dw_psp_lock_ops; > + dev->acquire_lock = psp_acquire_i2c_bus; > + dev->release_lock = psp_release_i2c_bus; > + > + return 0; > +} > + > +/* Unmap area used as a mailbox with PSP */ > +void i2c_dw_amdpsp_remove_lock_support(struct dw_i2c_dev *dev) > +{ > + iounmap(mbox_iomem); > +} > diff --git a/drivers/i2c/busses/i2c-designware-baytrail.c b/drivers/i2c/busses/i2c-designware-baytrail.c > index c6a7a00e1d52..45774aa47c28 100644 > --- a/drivers/i2c/busses/i2c-designware-baytrail.c > +++ b/drivers/i2c/busses/i2c-designware-baytrail.c > @@ -12,25 +12,25 @@ > > #include "i2c-designware-core.h" > > -int i2c_dw_probe_lock_support(struct dw_i2c_dev *dev) > +int i2c_dw_baytrail_probe_lock_support(struct dw_i2c_dev *dev) > { > acpi_status status; > unsigned long long shared_host = 0; > acpi_handle handle; > > - if (!dev || !dev->dev) > - return 0; > + if (!dev) > + return -ENODEV; > > handle = ACPI_HANDLE(dev->dev); > if (!handle) > - return 0; > + return -ENODEV; > > status = acpi_evaluate_integer(handle, "_SEM", NULL, &shared_host); > if (ACPI_FAILURE(status)) > - return 0; > + return -ENODEV; > > if (!shared_host) > - return 0; > + return -ENODEV; > > if (!iosf_mbi_available()) > return -EPROBE_DEFER; > diff --git a/drivers/i2c/busses/i2c-designware-core.h b/drivers/i2c/busses/i2c-designware-core.h > index 4b26cba40139..1d65212fddbd 100644 > --- a/drivers/i2c/busses/i2c-designware-core.h > +++ b/drivers/i2c/busses/i2c-designware-core.h > @@ -227,6 +227,8 @@ struct reset_control; > * @hs_lcnt: high speed LCNT value > * @acquire_lock: function to acquire a hardware lock on the bus > * @release_lock: function to release a hardware lock on the bus > + * @semaphore_idx: Index of table with semaphore type attached to the bus. It's > + * -1 if there is no semaphore. > * @shared_with_punit: true if this bus is shared with the SoCs PUNIT > * @disable: function to disable the controller > * @disable_int: function to disable all interrupts > @@ -285,6 +287,7 @@ struct dw_i2c_dev { > u16 hs_lcnt; > int (*acquire_lock)(void); > void (*release_lock)(void); > + int semaphore_idx; > bool shared_with_punit; > void (*disable)(struct dw_i2c_dev *dev); > void (*disable_int)(struct dw_i2c_dev *dev); > @@ -297,6 +300,7 @@ struct dw_i2c_dev { > > #define ACCESS_INTR_MASK BIT(0) > #define ACCESS_NO_IRQ_SUSPEND BIT(1) > +#define ARBITRATION_SEMAPHORE BIT(2) > > #define MODEL_MSCC_OCELOT BIT(8) > #define MODEL_BAIKAL_BT1 BIT(9) > @@ -310,6 +314,11 @@ struct dw_i2c_dev { > #define AMD_UCSI_INTR_REG 0x474 > #define AMD_UCSI_INTR_EN 0xd > > +struct i2c_dw_semaphore_callbacks { > + int (*probe)(struct dw_i2c_dev *dev); > + void (*remove)(struct dw_i2c_dev *dev); > +}; > + > int i2c_dw_init_regmap(struct dw_i2c_dev *dev); > u32 i2c_dw_scl_hcnt(u32 ic_clk, u32 tSYMBOL, u32 tf, int cond, int offset); > u32 i2c_dw_scl_lcnt(u32 ic_clk, u32 tLOW, u32 tf, int offset); > @@ -370,9 +379,12 @@ static inline void i2c_dw_configure(struct dw_i2c_dev *dev) > } > > #if IS_ENABLED(CONFIG_I2C_DESIGNWARE_BAYTRAIL) > -extern int i2c_dw_probe_lock_support(struct dw_i2c_dev *dev); > -#else > -static inline int i2c_dw_probe_lock_support(struct dw_i2c_dev *dev) { return 0; } > +int i2c_dw_baytrail_probe_lock_support(struct dw_i2c_dev *dev); > +#endif > + > +#if IS_ENABLED(CONFIG_I2C_DESIGNWARE_AMDPSP) > +int i2c_dw_amdpsp_probe_lock_support(struct dw_i2c_dev *dev); > +void i2c_dw_amdpsp_remove_lock_support(struct dw_i2c_dev *dev); > #endif > > int i2c_dw_validate_speed(struct dw_i2c_dev *dev); > diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c > index 2bd81abc86f6..9973ac894a51 100644 > --- a/drivers/i2c/busses/i2c-designware-platdrv.c > +++ b/drivers/i2c/busses/i2c-designware-platdrv.c > @@ -50,6 +50,7 @@ static const struct acpi_device_id dw_i2c_acpi_match[] = { > { "808622C1", ACCESS_NO_IRQ_SUSPEND }, > { "AMD0010", ACCESS_INTR_MASK }, > { "AMDI0010", ACCESS_INTR_MASK }, > + { "AMDI0019", ACCESS_INTR_MASK | ARBITRATION_SEMAPHORE }, > { "AMDI0510", 0 }, > { "APMC0D0F", 0 }, > { "HISI02A1", 0 }, > @@ -204,6 +205,63 @@ static const struct dmi_system_id dw_i2c_hwmon_class_dmi[] = { > { } /* terminate list */ > }; > > +static const struct i2c_dw_semaphore_callbacks i2c_dw_semaphore_cb_table[] = { > +#ifdef CONFIG_I2C_DESIGNWARE_BAYTRAIL > + { > + .probe = i2c_dw_baytrail_probe_lock_support, > + }, > +#endif > +#ifdef CONFIG_I2C_DESIGNWARE_AMDPSP > + { > + .probe = i2c_dw_amdpsp_probe_lock_support, > + .remove = i2c_dw_amdpsp_remove_lock_support, > + }, > +#endif > + {} > +}; > + > +static int i2c_dw_probe_lock_support(struct dw_i2c_dev *dev) > +{ > + const struct i2c_dw_semaphore_callbacks *ptr; > + int i = 0; > + int ret; > + > + ptr = i2c_dw_semaphore_cb_table; > + > + dev->semaphore_idx = -1; > + > + while (ptr->probe) { > + ret = ptr->probe(dev); > + if (ret) { > + /* > + * If there is no semaphore device attached to this > + * controller, we shouldn't abort general i2c_controller > + * probe. > + */ > + if (ret != -ENODEV) > + return ret; > + > + i++; > + ptr++; > + continue; > + } > + > + dev->semaphore_idx = i; > + break; > + } > + > + return 0; > +} > + > +static void i2c_dw_remove_lock_support(struct dw_i2c_dev *dev) > +{ > + if (dev->semaphore_idx < 0) > + return; > + > + if (i2c_dw_semaphore_cb_table[dev->semaphore_idx].remove) > + i2c_dw_semaphore_cb_table[dev->semaphore_idx].remove(dev); > +} > + > static int dw_i2c_plat_probe(struct platform_device *pdev) > { > struct i2c_adapter *adap; > @@ -334,6 +392,8 @@ static int dw_i2c_plat_remove(struct platform_device *pdev) > pm_runtime_put_sync(&pdev->dev); > dw_i2c_plat_pm_cleanup(dev); > > + i2c_dw_remove_lock_support(dev); > + > reset_control_assert(dev->rst); > > return 0;
On Wed, Feb 02, 2022 at 04:49:40PM -0600, Limonciello, Mario wrote: > On 2/2/2022 08:43, Jan Dabros wrote: ... > > + { "AMDI0019", APD_ADDR(wt_i2c_desc) }, > > Did you already check with anyone in AMD about reserving this ID? Oh, it's a very good point! I was under impression that Jan operates on allocated IDs... > Considering this design is specific to arbitration used for Chromebooks I > wonder if it is better to be GOOG ID? > > I can see it both ways, but if you didn't already talk to anyone and the > consensus is for it to be AMDI****, I will ask around internally about > reserving it / making sure there are no future or existing conflicts.
Hi Andy, Mario, czw., 3 lut 2022 o 11:43 Andy Shevchenko <andriy.shevchenko@linux.intel.com> napisał(a): > > On Wed, Feb 02, 2022 at 04:49:40PM -0600, Limonciello, Mario wrote: > > On 2/2/2022 08:43, Jan Dabros wrote: > > ... > > > > + { "AMDI0019", APD_ADDR(wt_i2c_desc) }, > > > > Did you already check with anyone in AMD about reserving this ID? > > Oh, it's a very good point! I was under impression that Jan operates on > allocated IDs... Yes, I received this ID from AMD. > > > Considering this design is specific to arbitration used for Chromebooks I > > wonder if it is better to be GOOG ID? > > > > I can see it both ways, but if you didn't already talk to anyone and the > > consensus is for it to be AMDI****, I will ask around internally about > > reserving it / making sure there are no future or existing conflicts. It was agreed with AMD that we will use "AMDI****" format. This ID is already reserved by them. Best Regards, Jan > > -- > With Best Regards, > Andy Shevchenko > >
diff --git a/drivers/i2c/busses/i2c-designware-common.c b/drivers/i2c/busses/i2c-designware-common.c index bf2a4920638a..9f8574320eb2 100644 --- a/drivers/i2c/busses/i2c-designware-common.c +++ b/drivers/i2c/busses/i2c-designware-common.c @@ -578,7 +578,12 @@ int i2c_dw_set_fifo_size(struct dw_i2c_dev *dev) * Try to detect the FIFO depth if not set by interface driver, * the depth could be from 2 to 256 from HW spec. */ + ret = i2c_dw_acquire_lock(dev); + if (ret) + return ret; + ret = regmap_read(dev->map, DW_IC_COMP_PARAM_1, ¶m); + i2c_dw_release_lock(dev); if (ret) return ret; @@ -607,6 +612,11 @@ u32 i2c_dw_func(struct i2c_adapter *adap) void i2c_dw_disable(struct dw_i2c_dev *dev) { u32 dummy; + int ret; + + ret = i2c_dw_acquire_lock(dev); + if (ret) + return; /* Disable controller */ __i2c_dw_disable(dev); @@ -614,6 +624,8 @@ void i2c_dw_disable(struct dw_i2c_dev *dev) /* Disable all interrupts */ regmap_write(dev->map, DW_IC_INTR_MASK, 0); regmap_read(dev->map, DW_IC_CLR_INTR, &dummy); + + i2c_dw_release_lock(dev); } void i2c_dw_disable_int(struct dw_i2c_dev *dev) diff --git a/drivers/i2c/busses/i2c-designware-master.c b/drivers/i2c/busses/i2c-designware-master.c index 9177463c2cbb..1a4b23556db3 100644 --- a/drivers/i2c/busses/i2c-designware-master.c +++ b/drivers/i2c/busses/i2c-designware-master.c @@ -905,7 +905,13 @@ int i2c_dw_probe_master(struct dw_i2c_dev *dev) irq_flags = IRQF_SHARED | IRQF_COND_SUSPEND; } + ret = i2c_dw_acquire_lock(dev); + if (ret) + return ret; + i2c_dw_disable_int(dev); + i2c_dw_release_lock(dev); + ret = devm_request_irq(dev->dev, dev->irq, i2c_dw_isr, irq_flags, dev_name(dev->dev), dev); if (ret) {
All accesses to controller's registers should be protected on probe, disable and xfer paths. This is needed for i2c bus controllers that are shared with but not controller by kernel. Signed-off-by: Jan Dabros <jsd@semihalf.com> --- drivers/i2c/busses/i2c-designware-common.c | 12 ++++++++++++ drivers/i2c/busses/i2c-designware-master.c | 6 ++++++ 2 files changed, 18 insertions(+)