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.
Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Signed-off-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx>
---
drivers/i2c/busses/i2c-designware-core.h | 3 ++
drivers/i2c/busses/i2c-designware-platdrv.c | 40 +++++++++++++++++++++
2 files changed, 43 insertions(+)
diff --git a/drivers/i2c/busses/i2c-designware-core.h b/drivers/i2c/busses/i2c-designware-core.h
index ad4e9619d365..f7883224e1af 100644
--- a/drivers/i2c/busses/i2c-designware-core.h
+++ b/drivers/i2c/busses/i2c-designware-core.h
@@ -238,6 +238,7 @@
struct dw_i2c_dev {
struct device *dev;
void __iomem *base;
+ void __iomem *ext;
struct completion cmd_complete;
struct clk *clk;
struct reset_control *rst;
@@ -292,6 +293,8 @@ 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 776d4354f366..0d9bfa45550d 100644
--- a/drivers/i2c/busses/i2c-designware-platdrv.c
+++ b/drivers/i2c/busses/i2c-designware-platdrv.c
@@ -170,11 +170,48 @@ 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)
@@ -309,6 +346,9 @@ 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
