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authorAlexandre Belloni <alexandre.belloni@bootlin.com>2018-08-31 17:11:12 +0200
committerWolfram Sang <wsa@the-dreams.de>2018-09-02 23:51:15 +0200
commit1bb39959623b438d6b7705abfd0538e8ef4f5f0f (patch)
tree0baa02df2f094bec970ed00bbbb2f3725d5a14d5 /drivers/i2c
parentdt-bindings: i2c: designware: document MSCC Ocelot bindings (diff)
downloadlinux-1bb39959623b438d6b7705abfd0538e8ef4f5f0f.tar.xz
linux-1bb39959623b438d6b7705abfd0538e8ef4f5f0f.zip
i2c: designware: add MSCC Ocelot support
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@linux.intel.com> Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> [wsa: made one function static] Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Diffstat (limited to 'drivers/i2c')
-rw-r--r--drivers/i2c/busses/i2c-designware-core.h3
-rw-r--r--drivers/i2c/busses/i2c-designware-platdrv.c40
2 files changed, 43 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-designware-core.h b/drivers/i2c/busses/i2c-designware-core.h
index f6cad20a86ff..5b550ab9a009 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 723892820e2b..a56af235e9a6 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;
+}
+
+static 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);