From patchwork Sat Mar 28 09:43:47 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Bosch X-Patchwork-Id: 244446 List-Id: U-Boot discussion From: stefan_b at posteo.net (Stefan Bosch) Date: Sat, 28 Mar 2020 10:43:47 +0100 Subject: [RFC PATCH v2 04/13] i2c: add nexell driver In-Reply-To: <1585388636-5404-1-git-send-email-stefan_b@posteo.net> References: <1585388636-5404-1-git-send-email-stefan_b@posteo.net> Message-ID: <1585388636-5404-5-git-send-email-stefan_b@posteo.net> Changes in relation to FriendlyARM's U-Boot nanopi2-v2016.01: - i2c/nx_i2c.c: Some adaptions mainly because of changes in "struct udevice". - several Bugfixes in nx_i2c.c. - the driver has been for s5p6818 only. Code extended appropriately in order s5p4418 is also working. - "probe_chip" added. Signed-off-by: Stefan Bosch --- Changes in v2: - commit "i2c: mmc: add nexell driver (gpio, i2c, mmc, pwm)" splitted into separate commits for gpio, i2c, mmc, pwm. - several Bugfixes in nx_i2c.c. - the i2c-driver has been for s5p6818 only. Code extended approriately in order s5p4418 is also working. - "probe_chip" added to the i2c-driver. - doc/device-tree-bindings/i2c/nx_i2c.txt added. doc/device-tree-bindings/i2c/nx_i2c.txt | 28 ++ drivers/i2c/Kconfig | 9 + drivers/i2c/Makefile | 1 + drivers/i2c/nx_i2c.c | 649 ++++++++++++++++++++++++++++++++ 4 files changed, 687 insertions(+) create mode 100644 doc/device-tree-bindings/i2c/nx_i2c.txt create mode 100644 drivers/i2c/nx_i2c.c diff --git a/doc/device-tree-bindings/i2c/nx_i2c.txt b/doc/device-tree-bindings/i2c/nx_i2c.txt new file mode 100644 index 0000000..9f3abe7 --- /dev/null +++ b/doc/device-tree-bindings/i2c/nx_i2c.txt @@ -0,0 +1,28 @@ +I2C controller embedded in Nexell's/Samsung's SoC S5P4418 and S5P6818 + +Driver: +- drivers/i2c/nx_i2c.c + +Required properties: +- #address-cells = <1>; +- #size-cells = <0>; +- compatible = "nexell,s5pxx18-i2c"; +- reg = ; + Where i2c_base has to be the base address of the i2c-register set. + I2C0: 0xc00a4000 + I2C1: 0xc00a5000 + I2C2: 0xc00a6000 + +Optional properties: +- clock-frequency: Desired I2C bus frequency in Hz, default value is 100000. +- i2c-sda-delay-ns (S5P6818 only): SDA delay in ns, default value is 0. +- Child nodes conforming to i2c bus binding. + +Example: + i2c0:i2c at c00a4000 { + #address-cells = <1>; + #size-cells = <0>; + compatible = "nexell,s5pxx18-i2c"; + reg = <0xc00a4000 0x100>; + clock-frequency = <400000>; + }; diff --git a/drivers/i2c/Kconfig b/drivers/i2c/Kconfig index 03d2fed..2cd0ed3 100644 --- a/drivers/i2c/Kconfig +++ b/drivers/i2c/Kconfig @@ -317,6 +317,15 @@ config SYS_MXC_I2C8_SLAVE MXC I2C8 Slave endif +config SYS_I2C_NEXELL + bool "Nexell I2C driver" + depends on DM_I2C + help + Add support for the Nexell I2C driver. This is used with various + Nexell parts such as S5Pxx18 series SoCs. All chips + have several I2C ports and all are provided, controlled by the + device tree. + config SYS_I2C_OMAP24XX bool "TI OMAP2+ I2C driver" depends on ARCH_OMAP2PLUS || ARCH_K3 diff --git a/drivers/i2c/Makefile b/drivers/i2c/Makefile index f5a471f..64b8ead 100644 --- a/drivers/i2c/Makefile +++ b/drivers/i2c/Makefile @@ -26,6 +26,7 @@ obj-$(CONFIG_SYS_I2C_LPC32XX) += lpc32xx_i2c.o obj-$(CONFIG_SYS_I2C_MESON) += meson_i2c.o obj-$(CONFIG_SYS_I2C_MVTWSI) += mvtwsi.o obj-$(CONFIG_SYS_I2C_MXC) += mxc_i2c.o +obj-$(CONFIG_SYS_I2C_NEXELL) += nx_i2c.o obj-$(CONFIG_SYS_I2C_OMAP24XX) += omap24xx_i2c.o obj-$(CONFIG_SYS_I2C_RCAR_I2C) += rcar_i2c.o obj-$(CONFIG_SYS_I2C_RCAR_IIC) += rcar_iic.o diff --git a/drivers/i2c/nx_i2c.c b/drivers/i2c/nx_i2c.c new file mode 100644 index 0000000..9bcf1f2 --- /dev/null +++ b/drivers/i2c/nx_i2c.c @@ -0,0 +1,649 @@ +#include +#include +#include +#include +#include +#include +#include +#include + +#define I2C_WRITE 0 +#define I2C_READ 1 + +#define I2CSTAT_MTM 0xC0 /* Master Transmit Mode */ +#define I2CSTAT_MRM 0x80 /* Master Receive Mode */ +#define I2CSTAT_BSY 0x20 /* Read: Bus Busy */ +#define I2CSTAT_SS 0x20 /* Write: START (1) / STOP (0) */ +#define I2CSTAT_RXTXEN 0x10 /* Rx/Tx enable */ +#define I2CSTAT_ABT 0x08 /* Arbitration bit */ +#define I2CSTAT_NACK 0x01 /* Nack bit */ +#define I2CCON_IRCLR 0x100 /* Interrupt Clear bit */ +#define I2CCON_ACKGEN 0x80 /* Acknowledge generation */ +#define I2CCON_IRENB 0x20 /* Interrupt Enable bit */ +#define I2CCON_IRPND 0x10 /* Interrupt pending bit */ + +#ifdef CONFIG_ARCH_S5P6818 +#define I2CLC_FILTER 0x04 /* SDA filter on */ +#else +#define STOPCON_CLR 0x01 /* Clock Line Release */ +#define STOPCON_DLR 0x02 /* Data Line Release */ +#define STOPCON_NAG 0x04 /* not-ackn. generation and data shift cont. */ +#endif + +#define I2C_TIMEOUT_MS 10 /* 10 ms */ + +#define I2C_M_NOSTOP 0x100 + +#define MAX_I2C_NUM 3 + +#define DEFAULT_SPEED 100000 /* default I2C speed [Hz] */ + +DECLARE_GLOBAL_DATA_PTR; + +struct nx_i2c_regs { + uint iiccon; + uint iicstat; + uint iicadd; + uint iicds; +#ifdef CONFIG_ARCH_S5P6818 + /* S5P6818: Offset 0x10 is Line Control Register (SDA-delay, Filter) */ + uint iiclc; +#else + /* S5P4418: Offset 0x10 is Stop Control Register */ + uint iicstopcon; +#endif +}; + +struct nx_i2c_bus { + uint bus_num; + struct nx_i2c_regs *regs; + uint speed; + uint target_speed; +#ifdef CONFIG_ARCH_S5P6818 + uint sda_delay; +#else + /* setup time for Stop condition [us] */ + uint tsu_stop; +#endif +}; + +/* s5pxx18 i2c must be reset before enabled */ +static void i2c_reset(int ch) +{ + int rst_id = RESET_ID_I2C0 + ch; + + nx_rstcon_setrst(rst_id, 0); + nx_rstcon_setrst(rst_id, 1); +} + +/* FIXME : this func will be removed after reset dm driver ported. + * set mmc pad alternative func. + */ +static void set_i2c_pad_func(uint bus_num) +{ + switch (bus_num) { + case 0: + nx_gpio_set_pad_function(3, 2, 1); + nx_gpio_set_pad_function(3, 3, 1); + break; + case 1: + nx_gpio_set_pad_function(3, 4, 1); + nx_gpio_set_pad_function(3, 5, 1); + break; + case 2: + nx_gpio_set_pad_function(3, 6, 1); + nx_gpio_set_pad_function(3, 7, 1); + break; + } +} + +static uint i2c_get_clkrate(struct nx_i2c_bus *bus) +{ + struct clk *clk; + int index = bus->bus_num; + char name[50] = {0, }; + + sprintf(name, "%s.%d", DEV_NAME_I2C, index); + clk = clk_get((const char *)name); + if (!clk) + return -1; + + return clk_get_rate(clk); +} + +static uint i2c_set_clk(struct nx_i2c_bus *bus, uint enb) +{ + struct clk *clk; + char name[50]; + + sprintf(name, "%s.%d", DEV_NAME_I2C, bus->bus_num); + clk = clk_get((const char *)name); + if (!clk) { + debug("%s(): clk_get(%s) error!\n", + __func__, (const char *)name); + return -EINVAL; + } + + if (enb) { + clk_disable(clk); + clk_enable(clk); + } else { + clk_disable(clk); + } + + return 0; +} + +#ifdef CONFIG_ARCH_S5P6818 +/* Set SDA line delay, not available at S5P4418 */ +static int nx_i2c_set_sda_delay(struct nx_i2c_bus *bus) +{ + struct nx_i2c_regs *i2c = bus->regs; + uint pclk = 0; + uint t_pclk = 0; + uint delay = 0; + + /* get input clock of the I2C-controller */ + pclk = i2c_get_clkrate(bus); + + if (bus->sda_delay) { + /* t_pclk = period time of one pclk [ns] */ + t_pclk = DIV_ROUND_UP(1000, pclk / 1000000); + /* delay = number of pclks required for sda_delay [ns] */ + delay = DIV_ROUND_UP(bus->sda_delay, t_pclk); + /* delay = register value (step of 5 clocks) */ + delay = DIV_ROUND_UP(delay, 5); + /* max. possible register value = 3 */ + if (delay > 3) { + delay = 3; + debug("%s(): sda-delay des.: %dns, sat. to max.: %dns (granularity: %dns)\n", + __func__, bus->sda_delay, t_pclk * delay * 5, + t_pclk * 5); + } else { + debug("%s(): sda-delay des.: %dns, act.: %dns (granularity: %dns)\n", + __func__, bus->sda_delay, t_pclk * delay * 5, + t_pclk * 5); + } + + delay |= I2CLC_FILTER; + } else { + delay = 0; + debug("%s(): sda-delay = 0\n", __func__); + } + + delay &= 0x7; + writel(delay, &i2c->iiclc); + + return 0; +} +#endif + +static int nx_i2c_set_bus_speed(struct udevice *dev, uint speed) +{ + struct nx_i2c_bus *bus = dev_get_priv(dev); + struct nx_i2c_regs *i2c = bus->regs; + unsigned long pclk, pres = 16, div; + + if (i2c_set_clk(bus, 1)) + return -EINVAL; + + /* get input clock of the I2C-controller */ + pclk = i2c_get_clkrate(bus); + + /* calculate prescaler and divisor values */ + if ((pclk / pres / (16 + 1)) > speed) + /* set prescaler to 256 */ + pres = 256; + + div = 0; + /* actual divider = div + 1 */ + while ((pclk / pres / (div + 1)) > speed) + div++; + + if (div > 0xF) { + debug("%s(): pres==%ld, div==0x%lx is saturated to 0xF !)\n", + __func__, pres, div); + div = 0xF; + } else { + debug("%s(): pres==%ld, div==0x%lx)\n", __func__, pres, div); + } + + /* set prescaler, divisor according to pclk, also set ACKGEN, IRQ */ + writel((div & 0x0F) | ((pres == 256) ? 0x40 : 0), &i2c->iiccon); + + /* init to SLAVE REVEIVE and set slaveaddr */ + writel(0, &i2c->iicstat); + writel(0x00, &i2c->iicadd); + + /* program Master Transmit (and implicit STOP) */ + writel(I2CSTAT_MTM | I2CSTAT_RXTXEN, &i2c->iicstat); + + /* calculate actual I2C speed [Hz] */ + bus->speed = pclk / ((div + 1) * pres); + debug("%s(): speed des.: %dHz, act.: %dHz\n", + __func__, speed, bus->speed); + +#ifdef CONFIG_ARCH_S5P6818 + nx_i2c_set_sda_delay(bus); +#else + /* setup time for Stop condition [us], min. 4us @ 100kHz I2C-clock */ + bus->tsu_stop = DIV_ROUND_UP(400, bus->speed / 1000); +#endif + if (i2c_set_clk(bus, 0)) + return -EINVAL; + return 0; +} + +static void i2c_process_node(struct udevice *dev) +{ + struct nx_i2c_bus *bus = dev_get_priv(dev); + const void *blob = gd->fdt_blob; + + int node; + + node = dev->node.of_offset; + + bus->target_speed = fdtdec_get_int(blob, node, + "clock-frequency", DEFAULT_SPEED); + +#ifdef CONFIG_ARCH_S5P6818 + bus->sda_delay = fdtdec_get_int(blob, node, "i2c-sda-delay-ns", 0); +#endif +} + +static int nx_i2c_probe(struct udevice *dev) +{ + struct nx_i2c_bus *bus = dev_get_priv(dev); + fdt_addr_t addr; + + /* get regs = i2c base address */ + addr = devfdt_get_addr(dev); + if (addr == FDT_ADDR_T_NONE) + return -EINVAL; + bus->regs = (struct nx_i2c_regs *)addr; + + bus->bus_num = dev->seq; + + /* i2c node parsing */ + i2c_process_node(dev); + if (!bus->target_speed) + return -ENODEV; + + /* reset */ + i2c_reset(bus->bus_num); + /* gpio pad */ + set_i2c_pad_func(bus->bus_num); + return 0; +} + +/* i2c bus busy check */ +static int i2c_is_busy(struct nx_i2c_regs *i2c) +{ + ulong start_time; + + start_time = get_timer(0); + while (readl(&i2c->iicstat) & I2CSTAT_BSY) { + if (get_timer(start_time) > I2C_TIMEOUT_MS) { + debug("Timeout\n"); + return -EBUSY; + } + } + return 0; +} + +/* irq enable/disable functions */ +static void i2c_enable_irq(struct nx_i2c_regs *i2c) +{ + unsigned int reg; + + reg = readl(&i2c->iiccon); + reg |= I2CCON_IRENB; + writel(reg, &i2c->iiccon); +} + +/* irq clear function */ +static void i2c_clear_irq(struct nx_i2c_regs *i2c) +{ + unsigned int reg; + + reg = readl(&i2c->iiccon); + /* reset interrupt pending flag */ + reg &= ~(I2CCON_IRPND); + /* + * Interrupt must also be cleared! + * Otherwise linux boot may hang after: + * [ 0.436000] NetLabel: unlabeled traffic allowed by default + * Next would be: + * [ 0.442000] clocksource: Switched to clocksource source timer + */ + reg |= I2CCON_IRCLR; + writel(reg, &i2c->iiccon); +} + +/* ack enable functions */ +static void i2c_enable_ack(struct nx_i2c_regs *i2c) +{ + unsigned int reg; + + reg = readl(&i2c->iiccon); + reg |= I2CCON_ACKGEN; + writel(reg, &i2c->iiccon); +} + +static void i2c_send_stop(struct nx_i2c_bus *bus) +{ + struct nx_i2c_regs *i2c = bus->regs; +#ifdef CONFIG_ARCH_S5P6818 + unsigned int reg; + + reg = readl(&i2c->iicstat); + reg |= I2CSTAT_MRM | I2CSTAT_RXTXEN; + reg &= (~I2CSTAT_SS); + + writel(reg, &i2c->iicstat); + i2c_clear_irq(i2c); + +#else /* S5P4418 */ + writel(STOPCON_NAG, &i2c->iicstopcon); + + i2c_clear_irq(i2c); + + /* + * Clock Line Release --> SDC changes from Low to High and + * SDA from High to Low + */ + writel(STOPCON_CLR, &i2c->iicstopcon); + + /* Hold SDA Low (Setup Time for Stop condition) */ + udelay(bus->tsu_stop); + + i2c_clear_irq(i2c); + + /* Master Receive Mode Stop --> SDA becomes High */ + writel(I2CSTAT_MRM, &i2c->iicstat); +#endif +} + +static int wait_for_xfer(struct nx_i2c_regs *i2c) +{ + unsigned long start_time = get_timer(0); + + do { + if (readl(&i2c->iiccon) & I2CCON_IRPND) + /* return -EREMOTEIO if not Acknowledged, otherwise 0 */ + return (readl(&i2c->iicstat) & I2CSTAT_NACK) ? + -EREMOTEIO : 0; + } while (get_timer(start_time) < I2C_TIMEOUT_MS); + + return -ETIMEDOUT; +} + +static int i2c_transfer(struct nx_i2c_regs *i2c, + uchar cmd_type, + uchar chip_addr, + uchar addr[], + uchar addr_len, + uchar data[], + unsigned short data_len, + uint seq) +{ + uint status; + int i = 0, result; + + /* Note: data_len = 0 is supported for "probe_chip" */ + + i2c_enable_irq(i2c); + i2c_enable_ack(i2c); + + /* Get the slave chip address going */ + /* Enable Rx/Tx */ + writel(I2CSTAT_RXTXEN, &i2c->iicstat); + + writel(chip_addr, &i2c->iicds); + status = I2CSTAT_RXTXEN | I2CSTAT_SS; + if (cmd_type == I2C_WRITE || (addr && addr_len)) + status |= I2CSTAT_MTM; + else + status |= I2CSTAT_MRM; + + writel(status, &i2c->iicstat); + if (seq) + i2c_clear_irq(i2c); + + /* Wait for chip address to transmit. */ + result = wait_for_xfer(i2c); + if (result) { + debug("%s: transmitting chip address failed\n", __func__); + goto bailout; + } + + /* If register address needs to be transmitted - do it now. */ + if (addr && addr_len) { /* register addr */ + while ((i < addr_len) && !result) { + writel(addr[i++], &i2c->iicds); + i2c_clear_irq(i2c); + result = wait_for_xfer(i2c); + } + + i = 0; + if (result) { + debug("%s: transmitting register address failed\n", + __func__); + goto bailout; + } + } + + switch (cmd_type) { + case I2C_WRITE: + while ((i < data_len) && !result) { + writel(data[i++], &i2c->iicds); + i2c_clear_irq(i2c); + result = wait_for_xfer(i2c); + } + break; + case I2C_READ: + if (addr && addr_len) { + /* + * Register address has been sent, now send slave chip + * address again to start the actual read transaction. + */ + writel(chip_addr, &i2c->iicds); + + /* Generate a re-START. */ + writel(I2CSTAT_MRM | I2CSTAT_RXTXEN | + I2CSTAT_SS, &i2c->iicstat); + i2c_clear_irq(i2c); + result = wait_for_xfer(i2c); + if (result) { + debug("%s: I2C_READ: sending chip addr. failed\n", + __func__); + goto bailout; + } + } + + while ((i < data_len) && !result) { + /* disable ACK for final READ */ + if (i == data_len - 1) + clrbits_le32(&i2c->iiccon, I2CCON_ACKGEN); + + i2c_clear_irq(i2c); + result = wait_for_xfer(i2c); + data[i++] = readb(&i2c->iicds); + } + + if (result == -EREMOTEIO) + /* Not Acknowledged --> normal terminated read. */ + result = 0; + else if (result == -ETIMEDOUT) + debug("%s: I2C_READ: time out\n", __func__); + else + debug("%s: I2C_READ: read not terminated with NACK\n", + __func__); + break; + + default: + debug("%s: bad call\n", __func__); + result = -EINVAL; + break; + } + +bailout: + return result; +} + +static int nx_i2c_read(struct udevice *dev, uchar chip_addr, uint addr, + uint alen, uchar *buffer, uint len, uint seq) +{ + struct nx_i2c_bus *i2c; + uchar xaddr[4]; + int ret; + + i2c = dev_get_priv(dev); + if (!i2c) + return -EFAULT; + + if (alen > 4) { + debug("I2C read: addr len %d not supported\n", alen); + return -EADDRNOTAVAIL; + } + + if (alen > 0) + xaddr[0] = (addr >> 24) & 0xFF; + + if (alen > 0) { + xaddr[0] = (addr >> 24) & 0xFF; + xaddr[1] = (addr >> 16) & 0xFF; + xaddr[2] = (addr >> 8) & 0xFF; + xaddr[3] = addr & 0xFF; + } + + ret = i2c_transfer(i2c->regs, I2C_READ, chip_addr << 1, + &xaddr[4 - alen], alen, buffer, len, seq); + + if (ret) { + debug("I2C read failed %d\n", ret); + return -EIO; + } + + return 0; +} + +static int nx_i2c_write(struct udevice *dev, uchar chip_addr, uint addr, + uint alen, uchar *buffer, uint len, uint seq) +{ + struct nx_i2c_bus *i2c; + uchar xaddr[4]; + int ret; + + i2c = dev_get_priv(dev); + if (!i2c) + return -EFAULT; + + if (alen > 4) { + debug("I2C write: addr len %d not supported\n", alen); + return -EINVAL; + } + + if (alen > 0) { + xaddr[0] = (addr >> 24) & 0xFF; + xaddr[1] = (addr >> 16) & 0xFF; + xaddr[2] = (addr >> 8) & 0xFF; + xaddr[3] = addr & 0xFF; + } + + ret = i2c_transfer(i2c->regs, I2C_WRITE, chip_addr << 1, + &xaddr[4 - alen], alen, buffer, len, seq); + if (ret) { + debug("I2C write failed %d\n", ret); + return -EIO; + } + + return 0; +} + +static int nx_i2c_xfer(struct udevice *dev, struct i2c_msg *msg, int nmsgs) +{ + struct nx_i2c_bus *bus = dev_get_priv(dev); + struct nx_i2c_regs *i2c = bus->regs; + int ret; + int i; + + /* The power loss by the clock, only during on/off. */ + ret = i2c_set_clk(bus, 1); + + if (!ret) + /* Bus State(Busy) check */ + ret = i2c_is_busy(i2c); + if (!ret) { + for (i = 0; i < nmsgs; msg++, i++) { + if (msg->flags & I2C_M_RD) { + ret = nx_i2c_read(dev, msg->addr, 0, 0, + msg->buf, msg->len, i); + } else { + ret = nx_i2c_write(dev, msg->addr, 0, 0, + msg->buf, msg->len, i); + } + + if (ret) { + debug("i2c_xfer: error sending\n"); + ret = -EREMOTEIO; + } + } + + i2c_send_stop(bus); + if (i2c_set_clk(bus, 0)) + ret = -EINVAL; + } + + return ret; +}; + +static int nx_i2c_probe_chip(struct udevice *dev, u32 chip_addr, + u32 chip_flags) +{ + int ret; + struct nx_i2c_bus *bus = dev_get_priv(dev); + + ret = i2c_set_clk(bus, 1); + + if (!ret) { + /* + * Send Chip Address only + * --> I2C transfer with data length and address length = 0. + * If there is a Slave, i2c_transfer() returns 0 (acknowledge + * transfer). + * I2C_WRITE must be used in order Master Transmit Mode is + * selected. Otherwise (in Master Receive Mode, I2C_READ) + * sending the stop condition below is not working (SDA does + * not transit to High). + */ + ret = i2c_transfer(bus->regs, I2C_WRITE, (uchar)chip_addr << 1, + NULL, 0, NULL, 0, 0); + + i2c_send_stop(bus); + if (i2c_set_clk(bus, 0)) + ret = -EINVAL; + } + + return ret; +} + +static const struct dm_i2c_ops nx_i2c_ops = { + .xfer = nx_i2c_xfer, + .probe_chip = nx_i2c_probe_chip, + .set_bus_speed = nx_i2c_set_bus_speed, +}; + +static const struct udevice_id nx_i2c_ids[] = { + { .compatible = "nexell,s5pxx18-i2c" }, + { } +}; + +U_BOOT_DRIVER(i2c_nexell) = { + .name = "i2c_nexell", + .id = UCLASS_I2C, + .of_match = nx_i2c_ids, + .probe = nx_i2c_probe, + .priv_auto_alloc_size = sizeof(struct nx_i2c_bus), + .ops = &nx_i2c_ops, +};