| Message ID | 20230522071030.5193-3-zhuyinbo@loongson.cn |
|---|---|
| State | Superseded |
| Headers | show |
| Series | spi: loongson: add bus driver for the loongson spi | expand |
Mon, May 22, 2023 at 03:10:30PM +0800, Yinbo Zhu kirjoitti: > This bus driver supports the Loongson SPI hardware controller in the > Loongson platforms and supports to use DTS and PCI framework to > register SPI device resources. It's polite to add reviewers of the previous versions to the Cc list. ... > +static void loongson_spi_set_clk(struct loongson_spi *loongson_spi, unsigned int hz) > +{ > + unsigned char val; > + unsigned int div, div_tmp; > + const char rdiv[12] = {0, 1, 4, 2, 3, 5, 6, 7, 8, 9, 10, 11}; static? > + > + div = clamp_val(DIV_ROUND_UP_ULL(loongson_spi->clk_rate, hz), 2, 4096); > + div_tmp = rdiv[fls(div - 1)]; > + loongson_spi->spcr = (div_tmp & GENMASK(1, 0)) >> 0; > + loongson_spi->sper = (div_tmp & GENMASK(3, 2)) >> 2; > + val = loongson_spi_read_reg(loongson_spi, LOONGSON_SPI_SPCR_REG); > + loongson_spi_write_reg(loongson_spi, LOONGSON_SPI_SPCR_REG, (val & ~3) | > + loongson_spi->spcr); > + val = loongson_spi_read_reg(loongson_spi, LOONGSON_SPI_SPER_REG); > + loongson_spi_write_reg(loongson_spi, LOONGSON_SPI_SPER_REG, (val & ~3) | > + loongson_spi->sper); > + loongson_spi->hz = hz; > +} ... > +static int loongson_spi_update_state(struct loongson_spi *loongson_spi, > + struct spi_device *spi, struct spi_transfer *t) > +{ > + unsigned int hz; > + > + if (t) > + hz = t->speed_hz; And if t is NULL? hz will be uninitialized. Don't you get a compiler warning? (Always test your code with `make W=1 ...`) > + if (hz && loongson_spi->hz != hz) > + loongson_spi_set_clk(loongson_spi, hz); > + > + if ((spi->mode ^ loongson_spi->mode) & SPI_MODE_X_MASK) > + loongson_spi_set_mode(loongson_spi, spi); > + > + return 0; > +} ... > + readb_poll_timeout(loongson_spi->base + LOONGSON_SPI_SPSR_REG, loongson_spi->spsr, > + (loongson_spi->spsr & 0x1) != 1, 1, MSEC_PER_SEC); Wouldn't be better to use ' == 0' in the conditional? Or if you think your approach is better (to show the exact expectation) the definition of the bit 0 might help #define LOONGSON_... BIT(0) readb_poll_timeout(loongson_spi->base + LOONGSON_SPI_SPSR_REG, loongson_spi->spsr, (loongson_spi->spsr & LOONGSON_...) != LOONGSON_..., 1, MSEC_PER_SEC); ... > + do { > + if (loongson_spi_write_read_8bit(spi, &tx, &rx, count) < 0) > + goto out; break; > + count--; > + } while (count); } while (--count); ? > +out: > + return xfer->len - count; Shouldn't you return an error code if the write failed? ... > + master = devm_spi_alloc_master(dev, sizeof(struct loongson_spi)); > + if (master == NULL) if (!master) > + return -ENOMEM; Why do you use deprecated naming? Can you use spi_controller* instead of spi_master* in all cases? ... > + master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH; = SPI_MODE_X_MASK | SPI_CS_HIGH; ... > + clk = devm_clk_get_optional(dev, NULL); > + if (!IS_ERR(clk)) > + spi->clk_rate = clk_get_rate(clk); > + else Redundant. Just check for the error first as it's very usual pattern in the Linux kernel. > + return dev_err_probe(dev, PTR_ERR(clk), "unable to get clock\n"); ... > +static void loongson_spi_pci_unregister(struct pci_dev *pdev) > +{ > + pcim_iounmap_regions(pdev, BIT(0)); Not needed due to 'm' in the API name, which means "managed". > + pci_disable_device(pdev); This is simply wrong. We don't do explicit clean up for managed resources. > +} That said, drop the ->remove() completely. ... > +static struct pci_device_id loongson_spi_devices[] = { > + { PCI_DEVICE(PCI_VENDOR_ID_LOONGSON, 0x7a0b) }, > + { PCI_DEVICE(PCI_VENDOR_ID_LOONGSON, 0x7a1b) }, > + { }, No comma for the terminator entry. It's by definition "terminating" something. > +}; ... > +#include <linux/of.h> There is no user of this header. Please, replace with what actually is being used (presumably mod_devicetable.h and maybe others). > +#include <linux/platform_device.h> > + > +#include "spi-loongson.h" > + > +static int loongson_spi_platform_probe(struct platform_device *pdev) > +{ > + int ret; > + void __iomem *reg_base; > + struct device *dev = &pdev->dev; > + > + reg_base = devm_platform_ioremap_resource(pdev, 0); > + if (IS_ERR(reg_base)) > + return PTR_ERR(reg_base); > + > + ret = loongson_spi_init_master(dev, reg_base); > + if (ret) > + return dev_err_probe(dev, ret, "failed to initialize master\n"); > + > + return ret; return 0; > +} ... > +#ifndef __LINUX_SPI_LOONGSON_H > +#define __LINUX_SPI_LOONGSON_H > + > +#include <linux/bits.h> > +#include <linux/device.h> This header is not used. > +#include <linux/pm.h> > +#include <linux/spi/spi.h> This neither. > +#include <linux/types.h> For them use forward declarations struct device; struct spi_controller; The rest of the inclusions is correct. ... > +#define LOONGSON_SPI_SPCR_REG 0x00 > +#define LOONGSON_SPI_SPSR_REG 0x01 > +#define LOONGSON_SPI_FIFO_REG 0x02 > +#define LOONGSON_SPI_SPER_REG 0x03 > +#define LOONGSON_SPI_PARA_REG 0x04 > +#define LOONGSON_SPI_SFCS_REG 0x05 > +#define LOONGSON_SPI_TIMI_REG 0x06 Where is this used outside of the main driver? > +/* Bits definition for Loongson SPI register */ > +#define LOONGSON_SPI_PARA_MEM_EN BIT(0) > +#define LOONGSON_SPI_SPCR_CPHA BIT(2) > +#define LOONGSON_SPI_SPCR_CPOL BIT(3) > +#define LOONGSON_SPI_SPCR_SPE BIT(6) > +#define LOONGSON_SPI_SPSR_WCOL BIT(6) > +#define LOONGSON_SPI_SPSR_SPIF BIT(7) > + > +struct loongson_spi { > + struct spi_master *master; > + void __iomem *base; > + int cs_active; > + unsigned int hz; > + unsigned char spcr; > + unsigned char sper; > + unsigned char spsr; > + unsigned char para; > + unsigned char sfcs; > + unsigned char timi; > + unsigned int mode; > + u64 clk_rate; > +}; > + > +int loongson_spi_init_master(struct device *dev, void __iomem *reg); > +extern const struct dev_pm_ops loongson_spi_dev_pm_ops; > +#endif /* __LINUX_SPI_LOONGSON_H */
On Wed, May 24, 2023 at 10:52 AM zhuyinbo <zhuyinbo@loongson.cn> wrote: > 在 2023/5/23 下午8:54, andy.shevchenko@gmail.com 写道: > > Mon, May 22, 2023 at 03:10:30PM +0800, Yinbo Zhu kirjoitti: ... > >> +static int loongson_spi_update_state(struct loongson_spi *loongson_spi, > >> + struct spi_device *spi, struct spi_transfer *t) > >> +{ > >> + unsigned int hz; > >> + > >> + if (t) > >> + hz = t->speed_hz; > > > > And if t is NULL? hz will be uninitialized. Don't you get a compiler warning? > > (Always test your code with `make W=1 ...`) > > I always use `make W=1` and I don't find any warning, but that what you > said was right and I will initial hz. Note, if hz == 0 when t == NULL, you can unify that check with the below. > >> + if (hz && loongson_spi->hz != hz) Something like if (t && _spi->hz != t->speed_hz) ...(..., t->speed_hz); In such a case you won't need a temporary variable. > >> + loongson_spi_set_clk(loongson_spi, hz); > >> + > >> + if ((spi->mode ^ loongson_spi->mode) & SPI_MODE_X_MASK) > >> + loongson_spi_set_mode(loongson_spi, spi); > >> + > >> + return 0; > >> +} ... > > Why do you use deprecated naming? Can you use spi_controller* instead of > > spi_master* in all cases? > > It seems was a personal code style issue and I don't find the > differences between spi_controller and spi_master, Using spi_controller* > is also acceptable to me and I will use spi_controller* instead of > spi_master* in all cases. Read this section (#4) in full https://kernel.org/doc/html/latest/process/coding-style.html#naming ... > >> + clk = devm_clk_get_optional(dev, NULL); > >> + if (!IS_ERR(clk)) > >> + spi->clk_rate = clk_get_rate(clk); > > > >> + else > > > > Redundant. Just check for the error first as it's very usual pattern in the > > Linux kernel. > > Like below ? > > clk = devm_clk_get_optional(dev, NULL); > - if (!IS_ERR(clk)) > - spi->clk_rate = clk_get_rate(clk); > - else > + if (IS_ERR(clk)) > return dev_err_probe(dev, PTR_ERR(clk), "unable to get > clock\n"); > > + spi->clk_rate = clk_get_rate(clk); Yes. > loongson_spi_reginit(spi); > >> + return dev_err_probe(dev, PTR_ERR(clk), "unable to get clock\n"); ... > >> + ret = loongson_spi_init_master(dev, reg_base); > >> + if (ret) > >> + return dev_err_probe(dev, ret, "failed to initialize master\n"); > >> + > >> + return ret; > > > > return 0; > > It seems was more appropriate that initialize ret then return ret. > Do you think so ? What do you mean and how does it help here? ... > >> +#include <linux/spi/spi.h> > > > > This neither. > > That other .c file seems to need it and I will move it to other .c > code file. Yes, please do. ... > >> +#define LOONGSON_SPI_SPCR_REG 0x00 > >> +#define LOONGSON_SPI_SPSR_REG 0x01 > >> +#define LOONGSON_SPI_FIFO_REG 0x02 > >> +#define LOONGSON_SPI_SPER_REG 0x03 > >> +#define LOONGSON_SPI_PARA_REG 0x04 > >> +#define LOONGSON_SPI_SFCS_REG 0x05 > >> +#define LOONGSON_SPI_TIMI_REG 0x06 > > > > Where is this used outside of the main driver? > > These definitions are only used in core.c Then the obvious question, why are they located in *.h? ... > >> +/* Bits definition for Loongson SPI register */ > >> +#define LOONGSON_SPI_PARA_MEM_EN BIT(0) > >> +#define LOONGSON_SPI_SPCR_CPHA BIT(2) > >> +#define LOONGSON_SPI_SPCR_CPOL BIT(3) > >> +#define LOONGSON_SPI_SPCR_SPE BIT(6) > >> +#define LOONGSON_SPI_SPSR_WCOL BIT(6) > >> +#define LOONGSON_SPI_SPSR_SPIF BIT(7) Similar question here.
On Wed, May 24, 2023 at 11:42:34AM +0300, Andy Shevchenko wrote: > On Wed, May 24, 2023 at 10:52 AM zhuyinbo <zhuyinbo@loongson.cn> wrote: > > >> +#define LOONGSON_SPI_SPCR_REG 0x00 > > >> +#define LOONGSON_SPI_SPSR_REG 0x01 > > >> +#define LOONGSON_SPI_FIFO_REG 0x02 > > >> +#define LOONGSON_SPI_SPER_REG 0x03 > > >> +#define LOONGSON_SPI_PARA_REG 0x04 > > >> +#define LOONGSON_SPI_SFCS_REG 0x05 > > >> +#define LOONGSON_SPI_TIMI_REG 0x06 > > > Where is this used outside of the main driver? > > These definitions are only used in core.c > Then the obvious question, why are they located in *.h? It's absolutely fine to put them in a header file, that's a perfectly normal way of writing code - it helps keep the driver a bit smaller by putting big piles of defines in a separate file, that can help make things a bit more manageable.
在 2023/5/24 下午4:42, Andy Shevchenko 写道: > On Wed, May 24, 2023 at 10:52 AM zhuyinbo <zhuyinbo@loongson.cn> wrote: >> 在 2023/5/23 下午8:54, andy.shevchenko@gmail.com 写道: >>> Mon, May 22, 2023 at 03:10:30PM +0800, Yinbo Zhu kirjoitti: > > ... > >>>> +static int loongson_spi_update_state(struct loongson_spi *loongson_spi, >>>> + struct spi_device *spi, struct spi_transfer *t) >>>> +{ >>>> + unsigned int hz; >>>> + >>>> + if (t) >>>> + hz = t->speed_hz; >>> >>> And if t is NULL? hz will be uninitialized. Don't you get a compiler warning? >>> (Always test your code with `make W=1 ...`) >> >> I always use `make W=1` and I don't find any warning, but that what you >> said was right and I will initial hz. > > Note, if hz == 0 when t == NULL, you can unify that check with the below. > >>>> + if (hz && loongson_spi->hz != hz) > > Something like > > if (t && _spi->hz != t->speed_hz) > ...(..., t->speed_hz); > > In such a case you won't need a temporary variable. okay, I got it. > >>>> + loongson_spi_set_clk(loongson_spi, hz); >>>> + >>>> + if ((spi->mode ^ loongson_spi->mode) & SPI_MODE_X_MASK) >>>> + loongson_spi_set_mode(loongson_spi, spi); >>>> + >>>> + return 0; >>>> +} > > ... > >>> Why do you use deprecated naming? Can you use spi_controller* instead of >>> spi_master* in all cases? >> >> It seems was a personal code style issue and I don't find the >> differences between spi_controller and spi_master, Using spi_controller* >> is also acceptable to me and I will use spi_controller* instead of >> spi_master* in all cases. > > Read this section (#4) in full > https://kernel.org/doc/html/latest/process/coding-style.html#naming okay, I got it. > > ... > >>>> + clk = devm_clk_get_optional(dev, NULL); >>>> + if (!IS_ERR(clk)) >>>> + spi->clk_rate = clk_get_rate(clk); >>> >>>> + else >>> >>> Redundant. Just check for the error first as it's very usual pattern in the >>> Linux kernel. >> >> Like below ? >> >> clk = devm_clk_get_optional(dev, NULL); >> - if (!IS_ERR(clk)) >> - spi->clk_rate = clk_get_rate(clk); >> - else >> + if (IS_ERR(clk)) >> return dev_err_probe(dev, PTR_ERR(clk), "unable to get >> clock\n"); >> >> + spi->clk_rate = clk_get_rate(clk); > > Yes. okay, I got it. > >> loongson_spi_reginit(spi); > >>>> + return dev_err_probe(dev, PTR_ERR(clk), "unable to get clock\n"); > > ... > >>>> + ret = loongson_spi_init_master(dev, reg_base); >>>> + if (ret) >>>> + return dev_err_probe(dev, ret, "failed to initialize master\n"); >>>> + >>>> + return ret; >>> >>> return 0; >> >> It seems was more appropriate that initialize ret then return ret. >> Do you think so ? > > What do you mean and how does it help here? I'm sorry, I was wrong before and the ret varible seems not to be initialized and it always record the return value for loongson_spi_init_master. It seems was appropriate that use "return ret" and I don't got your point that in probe for use "return 0" > > > ... > >>>> +#include <linux/spi/spi.h> >>> >>> This neither. >> >> That other .c file seems to need it and I will move it to other .c >> code file. > > Yes, please do. okay, I got it. Thanks, Yinbo
On Thu, May 25, 2023 at 6:34 AM zhuyinbo <zhuyinbo@loongson.cn> wrote: > 在 2023/5/24 下午4:42, Andy Shevchenko 写道: > > On Wed, May 24, 2023 at 10:52 AM zhuyinbo <zhuyinbo@loongson.cn> wrote: > >> 在 2023/5/23 下午8:54, andy.shevchenko@gmail.com 写道: > >>> Mon, May 22, 2023 at 03:10:30PM +0800, Yinbo Zhu kirjoitti: ... > >>>> + ret = loongson_spi_init_master(dev, reg_base); > >>>> + if (ret) > >>>> + return dev_err_probe(dev, ret, "failed to initialize master\n"); > >>>> + > >>>> + return ret; > >>> > >>> return 0; > >> > >> It seems was more appropriate that initialize ret then return ret. > >> Do you think so ? > > > > What do you mean and how does it help here? > > I'm sorry, I was wrong before and the ret varible seems not to be > initialized and it always record the return value for > loongson_spi_init_master. > > It seems was appropriate that use "return ret" and I don't got your > point that in probe for use "return 0" In the above excerpt you will return anything except 0 with return dev_err_probe(); line. Why do you still need to return ret; at the end of the function?
在 2023/5/25 下午5:16, Andy Shevchenko 写道: > On Thu, May 25, 2023 at 6:34 AM zhuyinbo <zhuyinbo@loongson.cn> wrote: >> 在 2023/5/24 下午4:42, Andy Shevchenko 写道: >>> On Wed, May 24, 2023 at 10:52 AM zhuyinbo <zhuyinbo@loongson.cn> wrote: >>>> 在 2023/5/23 下午8:54, andy.shevchenko@gmail.com 写道: >>>>> Mon, May 22, 2023 at 03:10:30PM +0800, Yinbo Zhu kirjoitti: > > ... > >>>>>> + ret = loongson_spi_init_master(dev, reg_base); >>>>>> + if (ret) >>>>>> + return dev_err_probe(dev, ret, "failed to initialize master\n"); >>>>>> + >>>>>> + return ret; >>>>> >>>>> return 0; >>>> >>>> It seems was more appropriate that initialize ret then return ret. >>>> Do you think so ? >>> >>> What do you mean and how does it help here? >> >> I'm sorry, I was wrong before and the ret varible seems not to be >> initialized and it always record the return value for >> loongson_spi_init_master. >> >> It seems was appropriate that use "return ret" and I don't got your >> point that in probe for use "return 0" > > In the above excerpt you will return anything except 0 with return > dev_err_probe(); line. Why do you still need to return ret; at the end > of the function? I'm sorry, I misread it and you are right and I will "return 0". Thanks, Yinbo.
diff --git a/MAINTAINERS b/MAINTAINERS index e49c04c53c99..fd63c5a1c886 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -12206,6 +12206,10 @@ M: Yinbo Zhu <zhuyinbo@loongson.cn> L: linux-spi@vger.kernel.org S: Maintained F: Documentation/devicetree/bindings/spi/loongson,ls2k-spi.yaml +F: drivers/spi/spi-loongson-core.c +F: drivers/spi/spi-loongson-pci.c +F: drivers/spi/spi-loongson-plat.c +F: drivers/spi/spi-loongson.h LSILOGIC MPT FUSION DRIVERS (FC/SAS/SPI) M: Sathya Prakash <sathya.prakash@broadcom.com> diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig index 3de2ebe8294a..6b953904792e 100644 --- a/drivers/spi/Kconfig +++ b/drivers/spi/Kconfig @@ -516,6 +516,32 @@ config SPI_LM70_LLP which interfaces to an LM70 temperature sensor using a parallel port. +config SPI_LOONGSON_CORE + tristate + depends on LOONGARCH || COMPILE_TEST + +config SPI_LOONGSON_PCI + tristate "Loongson SPI Controller PCI Driver Support" + select SPI_LOONGSON_CORE + depends on PCI && (LOONGARCH || COMPILE_TEST) + help + This bus driver supports the Loongson SPI hardware controller in + the Loongson platforms and supports to use PCI framework to + register SPI device resources. + Say Y or M here if you want to use the SPI controller on + Loongson platform. + +config SPI_LOONGSON_PLATFORM + tristate "Loongson SPI Controller Platform Driver Support" + select SPI_LOONGSON_CORE + depends on OF && (LOONGARCH || COMPILE_TEST) + help + This bus driver supports the Loongson SPI hardware controller in + the Loongson platforms and supports to use DTS framework to + register SPI device resources. + Say Y or M here if you want to use the SPI controller on + Loongson platform. + config SPI_LP8841_RTC tristate "ICP DAS LP-8841 SPI Controller for RTC" depends on MACH_PXA27X_DT || COMPILE_TEST diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile index 28c4817a8a74..3e933064d237 100644 --- a/drivers/spi/Makefile +++ b/drivers/spi/Makefile @@ -71,6 +71,9 @@ obj-$(CONFIG_SPI_INTEL_PLATFORM) += spi-intel-platform.o obj-$(CONFIG_SPI_LANTIQ_SSC) += spi-lantiq-ssc.o obj-$(CONFIG_SPI_JCORE) += spi-jcore.o obj-$(CONFIG_SPI_LM70_LLP) += spi-lm70llp.o +obj-$(CONFIG_SPI_LOONGSON_CORE) += spi-loongson-core.o +obj-$(CONFIG_SPI_LOONGSON_PCI) += spi-loongson-pci.o +obj-$(CONFIG_SPI_LOONGSON_PLATFORM) += spi-loongson-plat.o obj-$(CONFIG_SPI_LP8841_RTC) += spi-lp8841-rtc.o obj-$(CONFIG_SPI_MESON_SPICC) += spi-meson-spicc.o obj-$(CONFIG_SPI_MESON_SPIFC) += spi-meson-spifc.o diff --git a/drivers/spi/spi-loongson-core.c b/drivers/spi/spi-loongson-core.c new file mode 100644 index 000000000000..a556c60155d6 --- /dev/null +++ b/drivers/spi/spi-loongson-core.c @@ -0,0 +1,279 @@ +// SPDX-License-Identifier: GPL-2.0+ +// Loongson SPI Support +// Copyright (C) 2023 Loongson Technology Corporation Limited + +#include <linux/clk.h> +#include <linux/delay.h> +#include <linux/err.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/iopoll.h> +#include <linux/kernel.h> +#include <linux/module.h> + +#include "spi-loongson.h" + +static inline void loongson_spi_write_reg(struct loongson_spi *spi, unsigned char reg, + unsigned char data) +{ + writeb(data, spi->base + reg); +} + +static inline char loongson_spi_read_reg(struct loongson_spi *spi, unsigned char reg) +{ + return readb(spi->base + reg); +} + +static void loongson_spi_set_cs(struct spi_device *spi, bool val) +{ + int cs; + struct loongson_spi *loongson_spi = spi_master_get_devdata(spi->master); + + cs = loongson_spi_read_reg(loongson_spi, LOONGSON_SPI_SFCS_REG) + & ~(0x11 << spi_get_chipselect(spi, 0)); + loongson_spi_write_reg(loongson_spi, LOONGSON_SPI_SFCS_REG, + (val ? (0x11 << spi_get_chipselect(spi, 0)) : + (0x1 << spi_get_chipselect(spi, 0))) | cs); +} + +static void loongson_spi_set_clk(struct loongson_spi *loongson_spi, unsigned int hz) +{ + unsigned char val; + unsigned int div, div_tmp; + const char rdiv[12] = {0, 1, 4, 2, 3, 5, 6, 7, 8, 9, 10, 11}; + + div = clamp_val(DIV_ROUND_UP_ULL(loongson_spi->clk_rate, hz), 2, 4096); + div_tmp = rdiv[fls(div - 1)]; + loongson_spi->spcr = (div_tmp & GENMASK(1, 0)) >> 0; + loongson_spi->sper = (div_tmp & GENMASK(3, 2)) >> 2; + val = loongson_spi_read_reg(loongson_spi, LOONGSON_SPI_SPCR_REG); + loongson_spi_write_reg(loongson_spi, LOONGSON_SPI_SPCR_REG, (val & ~3) | + loongson_spi->spcr); + val = loongson_spi_read_reg(loongson_spi, LOONGSON_SPI_SPER_REG); + loongson_spi_write_reg(loongson_spi, LOONGSON_SPI_SPER_REG, (val & ~3) | + loongson_spi->sper); + loongson_spi->hz = hz; +} + +static void loongson_spi_set_mode(struct loongson_spi *loongson_spi, + struct spi_device *spi) +{ + unsigned char val; + + val = loongson_spi_read_reg(loongson_spi, LOONGSON_SPI_SPCR_REG); + val &= ~(LOONGSON_SPI_SPCR_CPOL | LOONGSON_SPI_SPCR_CPHA); + if (spi->mode & SPI_CPOL) + val |= LOONGSON_SPI_SPCR_CPOL; + if (spi->mode & SPI_CPHA) + val |= LOONGSON_SPI_SPCR_CPHA; + + loongson_spi_write_reg(loongson_spi, LOONGSON_SPI_SPCR_REG, val); + loongson_spi->mode |= spi->mode; +} + +static int loongson_spi_update_state(struct loongson_spi *loongson_spi, + struct spi_device *spi, struct spi_transfer *t) +{ + unsigned int hz; + + if (t) + hz = t->speed_hz; + + if (hz && loongson_spi->hz != hz) + loongson_spi_set_clk(loongson_spi, hz); + + if ((spi->mode ^ loongson_spi->mode) & SPI_MODE_X_MASK) + loongson_spi_set_mode(loongson_spi, spi); + + return 0; +} + +static int loongson_spi_setup(struct spi_device *spi) +{ + struct loongson_spi *loongson_spi; + + loongson_spi = spi_master_get_devdata(spi->master); + if (spi->bits_per_word % 8) + return -EINVAL; + + if (spi_get_chipselect(spi, 0) >= spi->master->num_chipselect) + return -EINVAL; + + loongson_spi->hz = 0; + loongson_spi_set_cs(spi, 1); + + return 0; +} + +static int loongson_spi_write_read_8bit(struct spi_device *spi, const u8 **tx_buf, + u8 **rx_buf, unsigned int num) +{ + struct loongson_spi *loongson_spi = spi_master_get_devdata(spi->master); + + if (tx_buf && *tx_buf) + loongson_spi_write_reg(loongson_spi, LOONGSON_SPI_FIFO_REG, *((*tx_buf)++)); + else + loongson_spi_write_reg(loongson_spi, LOONGSON_SPI_FIFO_REG, 0); + readb_poll_timeout(loongson_spi->base + LOONGSON_SPI_SPSR_REG, loongson_spi->spsr, + (loongson_spi->spsr & 0x1) != 1, 1, MSEC_PER_SEC); + + if (rx_buf && *rx_buf) + *(*rx_buf)++ = loongson_spi_read_reg(loongson_spi, LOONGSON_SPI_FIFO_REG); + else + loongson_spi_read_reg(loongson_spi, LOONGSON_SPI_FIFO_REG); + + return 0; +} + +static unsigned int loongson_spi_write_read(struct spi_device *spi, struct spi_transfer *xfer) +{ + unsigned int count; + const u8 *tx = xfer->tx_buf; + u8 *rx = xfer->rx_buf; + + count = xfer->len; + + do { + if (loongson_spi_write_read_8bit(spi, &tx, &rx, count) < 0) + goto out; + count--; + } while (count); + +out: + return xfer->len - count; +} + +static int loongson_spi_prepare_message(struct spi_controller *ctlr, struct spi_message *m) +{ + struct loongson_spi *loongson_spi = spi_controller_get_devdata(ctlr); + + loongson_spi->para = loongson_spi_read_reg(loongson_spi, LOONGSON_SPI_PARA_REG); + loongson_spi_write_reg(loongson_spi, LOONGSON_SPI_PARA_REG, loongson_spi->para & ~1); + + return 0; +} + +static int loongson_spi_transfer_one(struct spi_controller *ctrl, struct spi_device *spi, + struct spi_transfer *xfer) +{ + struct loongson_spi *loongson_spi = spi_master_get_devdata(spi->master); + + loongson_spi_update_state(loongson_spi, spi, xfer); + if (xfer->len) + xfer->len = loongson_spi_write_read(spi, xfer); + + return 0; +} + +static int loongson_spi_unprepare_message(struct spi_controller *ctrl, struct spi_message *m) +{ + struct loongson_spi *loongson_spi = spi_controller_get_devdata(ctrl); + + loongson_spi_write_reg(loongson_spi, LOONGSON_SPI_PARA_REG, loongson_spi->para); + + return 0; +} + +static void loongson_spi_reginit(struct loongson_spi *loongson_spi_dev) +{ + unsigned char val; + + val = loongson_spi_read_reg(loongson_spi_dev, LOONGSON_SPI_SPCR_REG); + val &= ~LOONGSON_SPI_SPCR_SPE; + loongson_spi_write_reg(loongson_spi_dev, LOONGSON_SPI_SPCR_REG, val); + + loongson_spi_write_reg(loongson_spi_dev, LOONGSON_SPI_SPSR_REG, + (LOONGSON_SPI_SPSR_SPIF | LOONGSON_SPI_SPSR_WCOL)); + + val = loongson_spi_read_reg(loongson_spi_dev, LOONGSON_SPI_SPCR_REG); + val |= LOONGSON_SPI_SPCR_SPE; + loongson_spi_write_reg(loongson_spi_dev, LOONGSON_SPI_SPCR_REG, val); +} + +int loongson_spi_init_master(struct device *dev, void __iomem *regs) +{ + struct spi_master *master; + struct loongson_spi *spi; + struct clk *clk; + + master = devm_spi_alloc_master(dev, sizeof(struct loongson_spi)); + if (master == NULL) + return -ENOMEM; + + master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH; + master->setup = loongson_spi_setup; + master->prepare_message = loongson_spi_prepare_message; + master->transfer_one = loongson_spi_transfer_one; + master->unprepare_message = loongson_spi_unprepare_message; + master->set_cs = loongson_spi_set_cs; + master->num_chipselect = 4; + device_set_node(&master->dev, dev_fwnode(dev)); + dev_set_drvdata(dev, master); + + spi = spi_master_get_devdata(master); + spi->base = regs; + spi->master = master; + + clk = devm_clk_get_optional(dev, NULL); + if (!IS_ERR(clk)) + spi->clk_rate = clk_get_rate(clk); + else + return dev_err_probe(dev, PTR_ERR(clk), "unable to get clock\n"); + + loongson_spi_reginit(spi); + + spi->mode = 0; + + return devm_spi_register_master(dev, master); +} +EXPORT_SYMBOL_NS_GPL(loongson_spi_init_master, SPI_LOONGSON_CORE); + +static int __maybe_unused loongson_spi_suspend(struct device *dev) +{ + struct loongson_spi *loongson_spi; + struct spi_master *master; + + master = dev_get_drvdata(dev); + spi_master_suspend(master); + + loongson_spi = spi_master_get_devdata(master); + + loongson_spi->spcr = loongson_spi_read_reg(loongson_spi, LOONGSON_SPI_SPCR_REG); + loongson_spi->sper = loongson_spi_read_reg(loongson_spi, LOONGSON_SPI_SPER_REG); + loongson_spi->spsr = loongson_spi_read_reg(loongson_spi, LOONGSON_SPI_SPSR_REG); + loongson_spi->para = loongson_spi_read_reg(loongson_spi, LOONGSON_SPI_PARA_REG); + loongson_spi->sfcs = loongson_spi_read_reg(loongson_spi, LOONGSON_SPI_SFCS_REG); + loongson_spi->timi = loongson_spi_read_reg(loongson_spi, LOONGSON_SPI_TIMI_REG); + + return 0; +} + +static int __maybe_unused loongson_spi_resume(struct device *dev) +{ + struct loongson_spi *loongson_spi; + struct spi_master *master; + + master = dev_get_drvdata(dev); + loongson_spi = spi_master_get_devdata(master); + + loongson_spi_write_reg(loongson_spi, LOONGSON_SPI_SPCR_REG, loongson_spi->spcr); + loongson_spi_write_reg(loongson_spi, LOONGSON_SPI_SPER_REG, loongson_spi->sper); + loongson_spi_write_reg(loongson_spi, LOONGSON_SPI_SPSR_REG, loongson_spi->spsr); + loongson_spi_write_reg(loongson_spi, LOONGSON_SPI_PARA_REG, loongson_spi->para); + loongson_spi_write_reg(loongson_spi, LOONGSON_SPI_SFCS_REG, loongson_spi->sfcs); + loongson_spi_write_reg(loongson_spi, LOONGSON_SPI_TIMI_REG, loongson_spi->timi); + + spi_master_resume(master); + + return 0; +} + +const struct dev_pm_ops loongson_spi_dev_pm_ops = { + .suspend = loongson_spi_suspend, + .resume = loongson_spi_resume, +}; +EXPORT_SYMBOL_NS_GPL(loongson_spi_dev_pm_ops, SPI_LOONGSON_CORE); + +MODULE_DESCRIPTION("Loongson SPI core driver"); +MODULE_LICENSE("GPL"); diff --git a/drivers/spi/spi-loongson-pci.c b/drivers/spi/spi-loongson-pci.c new file mode 100644 index 000000000000..c351a689150a --- /dev/null +++ b/drivers/spi/spi-loongson-pci.c @@ -0,0 +1,61 @@ +// SPDX-License-Identifier: GPL-2.0+ +// PCI interface driver for Loongson SPI Support +// Copyright (C) 2023 Loongson Technology Corporation Limited + +#include <linux/pci.h> + +#include "spi-loongson.h" + +static int loongson_spi_pci_register(struct pci_dev *pdev, + const struct pci_device_id *ent) +{ + int ret; + void __iomem *reg_base; + struct device *dev = &pdev->dev; + int pci_bar = 0; + + ret = pcim_enable_device(pdev); + if (ret < 0) + return dev_err_probe(dev, ret, "cannot enable pci device\n"); + + ret = pcim_iomap_regions(pdev, BIT(pci_bar), pci_name(pdev)); + if (ret) + return dev_err_probe(dev, ret, "failed to request and remap memory\n"); + + reg_base = pcim_iomap_table(pdev)[pci_bar]; + + ret = loongson_spi_init_master(dev, reg_base); + if (ret) + return dev_err_probe(dev, ret, "failed to initialize master\n"); + + return 0; +} + +static void loongson_spi_pci_unregister(struct pci_dev *pdev) +{ + pcim_iounmap_regions(pdev, BIT(0)); + pci_disable_device(pdev); +} + +static struct pci_device_id loongson_spi_devices[] = { + { PCI_DEVICE(PCI_VENDOR_ID_LOONGSON, 0x7a0b) }, + { PCI_DEVICE(PCI_VENDOR_ID_LOONGSON, 0x7a1b) }, + { }, +}; +MODULE_DEVICE_TABLE(pci, loongson_spi_devices); + +static struct pci_driver loongson_spi_pci_driver = { + .name = "loongson-spi-pci", + .id_table = loongson_spi_devices, + .probe = loongson_spi_pci_register, + .remove = loongson_spi_pci_unregister, + .driver = { + .bus = &pci_bus_type, + .pm = &loongson_spi_dev_pm_ops, + }, +}; +module_pci_driver(loongson_spi_pci_driver); + +MODULE_DESCRIPTION("Loongson spi pci driver"); +MODULE_LICENSE("GPL"); +MODULE_IMPORT_NS(SPI_LOONGSON_CORE); diff --git a/drivers/spi/spi-loongson-plat.c b/drivers/spi/spi-loongson-plat.c new file mode 100644 index 000000000000..2e0388d84044 --- /dev/null +++ b/drivers/spi/spi-loongson-plat.c @@ -0,0 +1,46 @@ +// SPDX-License-Identifier: GPL-2.0+ +// Platform driver for Loongson SPI Support +// Copyright (C) 2023 Loongson Technology Corporation Limited + +#include <linux/of.h> +#include <linux/platform_device.h> + +#include "spi-loongson.h" + +static int loongson_spi_platform_probe(struct platform_device *pdev) +{ + int ret; + void __iomem *reg_base; + struct device *dev = &pdev->dev; + + reg_base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(reg_base)) + return PTR_ERR(reg_base); + + ret = loongson_spi_init_master(dev, reg_base); + if (ret) + return dev_err_probe(dev, ret, "failed to initialize master\n"); + + return ret; +} + +static const struct of_device_id loongson_spi_id_table[] = { + { .compatible = "loongson,ls2k-spi" }, + { } +}; +MODULE_DEVICE_TABLE(of, loongson_spi_id_table); + +static struct platform_driver loongson_spi_plat_driver = { + .probe = loongson_spi_platform_probe, + .driver = { + .name = "loongson-spi", + .bus = &platform_bus_type, + .pm = &loongson_spi_dev_pm_ops, + .of_match_table = loongson_spi_id_table, + }, +}; +module_platform_driver(loongson_spi_plat_driver); + +MODULE_DESCRIPTION("Loongson spi platform driver"); +MODULE_LICENSE("GPL"); +MODULE_IMPORT_NS(SPI_LOONGSON_CORE); diff --git a/drivers/spi/spi-loongson.h b/drivers/spi/spi-loongson.h new file mode 100644 index 000000000000..5dca9750efa3 --- /dev/null +++ b/drivers/spi/spi-loongson.h @@ -0,0 +1,47 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* Header File for Loongson SPI Driver. */ +/* Copyright (C) 2023 Loongson Technology Corporation Limited */ + +#ifndef __LINUX_SPI_LOONGSON_H +#define __LINUX_SPI_LOONGSON_H + +#include <linux/bits.h> +#include <linux/device.h> +#include <linux/pm.h> +#include <linux/spi/spi.h> +#include <linux/types.h> + +#define LOONGSON_SPI_SPCR_REG 0x00 +#define LOONGSON_SPI_SPSR_REG 0x01 +#define LOONGSON_SPI_FIFO_REG 0x02 +#define LOONGSON_SPI_SPER_REG 0x03 +#define LOONGSON_SPI_PARA_REG 0x04 +#define LOONGSON_SPI_SFCS_REG 0x05 +#define LOONGSON_SPI_TIMI_REG 0x06 + +/* Bits definition for Loongson SPI register */ +#define LOONGSON_SPI_PARA_MEM_EN BIT(0) +#define LOONGSON_SPI_SPCR_CPHA BIT(2) +#define LOONGSON_SPI_SPCR_CPOL BIT(3) +#define LOONGSON_SPI_SPCR_SPE BIT(6) +#define LOONGSON_SPI_SPSR_WCOL BIT(6) +#define LOONGSON_SPI_SPSR_SPIF BIT(7) + +struct loongson_spi { + struct spi_master *master; + void __iomem *base; + int cs_active; + unsigned int hz; + unsigned char spcr; + unsigned char sper; + unsigned char spsr; + unsigned char para; + unsigned char sfcs; + unsigned char timi; + unsigned int mode; + u64 clk_rate; +}; + +int loongson_spi_init_master(struct device *dev, void __iomem *reg); +extern const struct dev_pm_ops loongson_spi_dev_pm_ops; +#endif /* __LINUX_SPI_LOONGSON_H */
This bus driver supports the Loongson SPI hardware controller in the Loongson platforms and supports to use DTS and PCI framework to register SPI device resources. Signed-off-by: Yinbo Zhu <zhuyinbo@loongson.cn> --- MAINTAINERS | 4 + drivers/spi/Kconfig | 26 +++ drivers/spi/Makefile | 3 + drivers/spi/spi-loongson-core.c | 279 ++++++++++++++++++++++++++++++++ drivers/spi/spi-loongson-pci.c | 61 +++++++ drivers/spi/spi-loongson-plat.c | 46 ++++++ drivers/spi/spi-loongson.h | 47 ++++++ 7 files changed, 466 insertions(+) create mode 100644 drivers/spi/spi-loongson-core.c create mode 100644 drivers/spi/spi-loongson-pci.c create mode 100644 drivers/spi/spi-loongson-plat.c create mode 100644 drivers/spi/spi-loongson.h