On Tue, 2018-07-17 at 13:48 +0200, Alexandre Belloni wrote: > 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. Thanks for information you provided. See my comments below. > struct dw_i2c_dev { > struct device *dev; > void __iomem *base; > + void __iomem *base_ext; Maybe simple "ext"? Up to you. > +#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->base_ext + MSCC_ICPU_CFG_TWI_DELAY); > + > + return 0; > +} (1) > > + if (of_device_is_compatible(pdev->dev.of_node, "mscc,ocelot- > i2c")) { > + mem = platform_get_resource(pdev, IORESOURCE_MEM, 1); > + dev->base_ext = devm_ioremap_resource(&pdev->dev, > mem); > + if (!IS_ERR(dev->base_ext)) > + dev->set_sda_hold_time = > mscc_twi_set_sda_hold_time; > + } (2) > static const struct of_device_id dw_i2c_of_match[] = { > { .compatible = "snps,designware-i2c", }, > + { .compatible = "mscc,ocelot-i2c", }, > {}, > }; (3) I would rather place them in analogue how we do for ACPI, i.e. --- 8< --- 8< --- ... #define MODEL_MSCC_OCELOT 0x00000200 #define MODEL_MASK 0x00000f00 ... #ifdef CONFIG_OF -->(1) int dw_i2c_of_configure(pdev) { ... -->(2) (perhaps we don't care if it goes without condition, or move it below in the corresponding case? ... switch(dev->flags & MODEL_MASK) { case MODEL_MSCC_OCELOT: ... break; default: break; } return 0; } -->(3) ... { .compatible = "mscc,ocelot-i2c", .data = (void *)MODEL_MSCC_OCELOT }, ... #else static inline int dw_i2c_of_configure(pdev) { return -ENODEV; } #endif ... ->probe(): ... /* REPLACE THIS in dw_i2c_acpi_configure() by below in ->probe(): * id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev- >dev); * if (id && id->driver_data) * dev->flags |= (u32)id->driver_data; */ dev->flags |= (u32)device_get_match_data(&pdev->dev); if (&pdev->dev.of_node) dw_i2c_of_configure(pdev); ... --- 8< --- 8< --- What do you think? -- Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> Intel Finland Oy