On Wed, May 27, 2020 at 03:01:11PM +0300, Serge Semin wrote: > Baikal-T1 System Controller is equipped with a dedicated I2C Controller > which functionality is based on the DW APB I2C IP-core, the only > difference in a way it' registers are accessed. There are three access > register provided in the System Controller registers map, which indirectly > address the normal DW APB I2C registers space. So in order to have the > Baikal-T1 System I2C Controller supported by the common DW APB I2C driver > we created a dedicated Dw I2C controller model quirk, which retrieves the > syscon regmap from the parental dt node and creates a new regmap based on > it.
Yes, you see how cool it is now! FWIW, Reviewed-by: Andy Shevchenko <[email protected]> > Signed-off-by: Serge Semin <[email protected]> > Cc: Alexey Malahov <[email protected]> > Cc: Thomas Bogendoerfer <[email protected]> > Cc: Rob Herring <[email protected]> > Cc: [email protected] > Cc: [email protected] > > --- > > Changelog v3: > - This is a new patch, which has been created due to declining the > glue-layer approach. > > Changelog v4: > - Use PTR_ERR_OR_ZERO() helper in the bt1_i2c_request_regs() method. > --- > drivers/i2c/busses/Kconfig | 3 +- > drivers/i2c/busses/i2c-designware-core.h | 3 + > drivers/i2c/busses/i2c-designware-platdrv.c | 78 ++++++++++++++++++++- > 3 files changed, 81 insertions(+), 3 deletions(-) > > diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig > index 259e2325712a..0cf7aea30138 100644 > --- a/drivers/i2c/busses/Kconfig > +++ b/drivers/i2c/busses/Kconfig > @@ -541,8 +541,9 @@ config I2C_DESIGNWARE_SLAVE > > config I2C_DESIGNWARE_PLATFORM > tristate "Synopsys DesignWare Platform" > - select I2C_DESIGNWARE_CORE > depends on (ACPI && COMMON_CLK) || !ACPI > + select I2C_DESIGNWARE_CORE > + select MFD_SYSCON if MIPS_BAIKAL_T1 > help > If you say yes to this option, support will be included for the > Synopsys DesignWare I2C adapter. > diff --git a/drivers/i2c/busses/i2c-designware-core.h > b/drivers/i2c/busses/i2c-designware-core.h > index f5bbe3d6bcf8..556673a1f61b 100644 > --- a/drivers/i2c/busses/i2c-designware-core.h > +++ b/drivers/i2c/busses/i2c-designware-core.h > @@ -183,6 +183,7 @@ struct reset_control; > * struct dw_i2c_dev - private i2c-designware data > * @dev: driver model device node > * @map: IO registers map > + * @sysmap: System controller registers map > * @base: IO registers pointer > * @ext: Extended IO registers pointer > * @cmd_complete: tx completion indicator > @@ -235,6 +236,7 @@ struct reset_control; > struct dw_i2c_dev { > struct device *dev; > struct regmap *map; > + struct regmap *sysmap; > void __iomem *base; > void __iomem *ext; > struct completion cmd_complete; > @@ -290,6 +292,7 @@ struct dw_i2c_dev { > #define ACCESS_NO_IRQ_SUSPEND 0x00000002 > > #define MODEL_MSCC_OCELOT 0x00000100 > +#define MODEL_BAIKAL_BT1 0x00000200 > #define MODEL_MASK 0x00000f00 > > int i2c_dw_init_regmap(struct dw_i2c_dev *dev); > diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c > b/drivers/i2c/busses/i2c-designware-platdrv.c > index 061c8d506c7c..d9c5337bb22b 100644 > --- a/drivers/i2c/busses/i2c-designware-platdrv.c > +++ b/drivers/i2c/busses/i2c-designware-platdrv.c > @@ -18,6 +18,7 @@ > #include <linux/interrupt.h> > #include <linux/io.h> > #include <linux/kernel.h> > +#include <linux/mfd/syscon.h> > #include <linux/module.h> > #include <linux/of.h> > #include <linux/platform_data/i2c-designware.h> > @@ -25,6 +26,7 @@ > #include <linux/pm.h> > #include <linux/pm_runtime.h> > #include <linux/property.h> > +#include <linux/regmap.h> > #include <linux/reset.h> > #include <linux/sched.h> > #include <linux/slab.h> > @@ -58,6 +60,63 @@ MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match); > #endif > > #ifdef CONFIG_OF > +#define BT1_I2C_CTL 0x100 > +#define BT1_I2C_CTL_ADDR_MASK GENMASK(7, 0) > +#define BT1_I2C_CTL_WR BIT(8) > +#define BT1_I2C_CTL_GO BIT(31) > +#define BT1_I2C_DI 0x104 > +#define BT1_I2C_DO 0x108 > + > +static int bt1_i2c_read(void *context, unsigned int reg, unsigned int *val) > +{ > + struct dw_i2c_dev *dev = context; > + int ret; > + > + /* > + * Note these methods shouldn't ever fail because the system controller > + * registers are memory mapped. We check the return value just in case. > + */ > + ret = regmap_write(dev->sysmap, BT1_I2C_CTL, > + BT1_I2C_CTL_GO | (reg & BT1_I2C_CTL_ADDR_MASK)); > + if (ret) > + return ret; > + > + return regmap_read(dev->sysmap, BT1_I2C_DO, val); > +} > + > +static int bt1_i2c_write(void *context, unsigned int reg, unsigned int val) > +{ > + struct dw_i2c_dev *dev = context; > + int ret; > + > + ret = regmap_write(dev->sysmap, BT1_I2C_DI, val); > + if (ret) > + return ret; > + > + return regmap_write(dev->sysmap, BT1_I2C_CTL, > + BT1_I2C_CTL_GO | BT1_I2C_CTL_WR | (reg & > BT1_I2C_CTL_ADDR_MASK)); > +} > + > +static struct regmap_config bt1_i2c_cfg = { > + .reg_bits = 32, > + .val_bits = 32, > + .reg_stride = 4, > + .fast_io = true, > + .reg_read = bt1_i2c_read, > + .reg_write = bt1_i2c_write, > + .max_register = DW_IC_COMP_TYPE > +}; > + > +static int bt1_i2c_request_regs(struct dw_i2c_dev *dev) > +{ > + dev->sysmap = syscon_node_to_regmap(dev->dev->of_node->parent); > + if (IS_ERR(dev->sysmap)) > + return PTR_ERR(dev->sysmap); > + > + dev->map = devm_regmap_init(dev->dev, NULL, dev, &bt1_i2c_cfg); > + return PTR_ERR_OR_ZERO(dev->map); > +} > + > #define MSCC_ICPU_CFG_TWI_DELAY 0x0 > #define MSCC_ICPU_CFG_TWI_DELAY_ENABLE BIT(0) > #define MSCC_ICPU_CFG_TWI_SPIKE_FILTER 0x4 > @@ -90,10 +149,16 @@ static int dw_i2c_of_configure(struct platform_device > *pdev) > static const struct of_device_id dw_i2c_of_match[] = { > { .compatible = "snps,designware-i2c", }, > { .compatible = "mscc,ocelot-i2c", .data = (void *)MODEL_MSCC_OCELOT }, > + { .compatible = "baikal,bt1-sys-i2c", .data = (void *)MODEL_BAIKAL_BT1 > }, > {}, > }; > MODULE_DEVICE_TABLE(of, dw_i2c_of_match); > #else > +static int bt1_i2c_request_regs(struct dw_i2c_dev *dev) > +{ > + return -ENODEV; > +} > + > static inline int dw_i2c_of_configure(struct platform_device *pdev) > { > return -ENODEV; > @@ -111,10 +176,19 @@ static void dw_i2c_plat_pm_cleanup(struct dw_i2c_dev > *dev) > static int dw_i2c_plat_request_regs(struct dw_i2c_dev *dev) > { > struct platform_device *pdev = to_platform_device(dev->dev); > + int ret; > > - dev->base = devm_platform_ioremap_resource(pdev, 0); > + switch (dev->flags & MODEL_MASK) { > + case MODEL_BAIKAL_BT1: > + ret = bt1_i2c_request_regs(dev); > + break; > + default: > + dev->base = devm_platform_ioremap_resource(pdev, 0); > + ret = PTR_ERR_OR_ZERO(dev->base); > + break; > + } > > - return PTR_ERR_OR_ZERO(dev->base); > + return ret; > } > > static int dw_i2c_plat_probe(struct platform_device *pdev) > -- > 2.26.2 > -- With Best Regards, Andy Shevchenko
