The Microsemi Ocelot I2C controller is a designware IP. It also has a second set of registers to allow tweaking SDA hold time and spike filtering.
Cc: Rob Herring <[email protected]> Reviewed-by: Andy Shevchenko <[email protected]> Signed-off-by: Alexandre Belloni <[email protected]> --- .../bindings/i2c/i2c-designware.txt | 9 ++++- drivers/i2c/busses/i2c-designware-core.h | 3 ++ drivers/i2c/busses/i2c-designware-platdrv.c | 40 +++++++++++++++++++ 3 files changed, 50 insertions(+), 2 deletions(-) diff --git a/Documentation/devicetree/bindings/i2c/i2c-designware.txt b/Documentation/devicetree/bindings/i2c/i2c-designware.txt index fbb0a6d8b964..7886f2dc6675 100644 --- a/Documentation/devicetree/bindings/i2c/i2c-designware.txt +++ b/Documentation/devicetree/bindings/i2c/i2c-designware.txt @@ -2,7 +2,8 @@ Required properties : - - compatible : should be "snps,designware-i2c" + - compatible : should be "snps,designware-i2c" or "mscc,ocelot-i2c" followed by + "snps,designware-i2c" for fallback - reg : Offset and length of the register set for the device - interrupts : <IRQ> where IRQ is the interrupt number. @@ -11,8 +12,12 @@ Recommended properties : - clock-frequency : desired I2C bus clock frequency in Hz. Optional properties : + - reg : for "mscc,ocelot-i2c", a second register set to configure the SDA hold + time, named ICPU_CFG:TWI_DELAY in the datasheet. + - i2c-sda-hold-time-ns : should contain the SDA hold time in nanoseconds. - This option is only supported in hardware blocks version 1.11a or newer. + This option is only supported in hardware blocks version 1.11a or newer and + on Microsemi SoCs ("mscc,ocelot-i2c" compatible). - i2c-scl-falling-time-ns : should contain the SCL falling time in nanoseconds. This value which is by default 300ns is used to compute the tLOW period. diff --git a/drivers/i2c/busses/i2c-designware-core.h b/drivers/i2c/busses/i2c-designware-core.h index 870444bbbcc4..5e240ce9968e 100644 --- a/drivers/i2c/busses/i2c-designware-core.h +++ b/drivers/i2c/busses/i2c-designware-core.h @@ -225,6 +225,7 @@ struct dw_i2c_dev { struct device *dev; void __iomem *base; + void __iomem *ext; struct completion cmd_complete; struct clk *clk; struct reset_control *rst; @@ -279,6 +280,8 @@ struct dw_i2c_dev { #define ACCESS_INTR_MASK 0x00000004 #define MODEL_CHERRYTRAIL 0x00000100 +#define MODEL_MSCC_OCELOT 0x00000200 +#define MODEL_MASK 0x00000f00 u32 dw_readl(struct dw_i2c_dev *dev, int offset); void dw_writel(struct dw_i2c_dev *dev, u32 b, int offset); diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c index 1bcaab777a2e..39aab03cb416 100644 --- a/drivers/i2c/busses/i2c-designware-platdrv.c +++ b/drivers/i2c/busses/i2c-designware-platdrv.c @@ -157,11 +157,48 @@ static inline int dw_i2c_acpi_configure(struct platform_device *pdev) #endif #ifdef CONFIG_OF +#define MSCC_ICPU_CFG_TWI_DELAY 0x0 +#define MSCC_ICPU_CFG_TWI_DELAY_ENABLE BIT(0) +#define MSCC_ICPU_CFG_TWI_SPIKE_FILTER 0x4 + +static int mscc_twi_set_sda_hold_time(struct dw_i2c_dev *dev) +{ + writel((dev->sda_hold_time << 1) | MSCC_ICPU_CFG_TWI_DELAY_ENABLE, + dev->ext + MSCC_ICPU_CFG_TWI_DELAY); + + return 0; +} + +int dw_i2c_of_configure(struct platform_device *pdev) +{ + struct dw_i2c_dev *dev = platform_get_drvdata(pdev); + struct resource *mem; + + switch (dev->flags & MODEL_MASK) { + case MODEL_MSCC_OCELOT: + mem = platform_get_resource(pdev, IORESOURCE_MEM, 1); + dev->ext = devm_ioremap_resource(&pdev->dev, mem); + if (!IS_ERR(dev->ext)) + dev->set_sda_hold_time = mscc_twi_set_sda_hold_time; + break; + default: + break; + } + + return 0; +} + static const struct of_device_id dw_i2c_of_match[] = { { .compatible = "snps,designware-i2c", }, + { .compatible = "mscc,ocelot-i2c", .data = (void *)MODEL_MSCC_OCELOT }, {}, }; MODULE_DEVICE_TABLE(of, dw_i2c_of_match); +#else +static inline int dw_i2c_of_configure(struct platform_device *pdev) +{ + return -ENODEV; +} #endif static void i2c_dw_configure_master(struct dw_i2c_dev *dev) @@ -296,6 +333,9 @@ static int dw_i2c_plat_probe(struct platform_device *pdev) dev->flags |= (uintptr_t)device_get_match_data(&pdev->dev); + if (pdev->dev.of_node) + dw_i2c_of_configure(pdev); + if (has_acpi_companion(&pdev->dev)) dw_i2c_acpi_configure(pdev); -- 2.18.0
