[PATCH v2] i2c-designware: Add suport for AMD i2c controller

[Carl Peng <carlpeng008-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>]

AMD i2c bus controller is ACPI device, its ACPI ID
is "AMD0010". This patch is used to add support for
AMD i2c bus controller in the Designware platfrom
driver.

Signed-off-by: Carl Peng <carlpeng008-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
---
 drivers/i2c/busses/i2c-designware-core.h    |  1 +
 drivers/i2c/busses/i2c-designware-platdrv.c | 35 +++++++++++++++++++++++------
 2 files changed, 29 insertions(+), 7 deletions(-)

diff --git a/drivers/i2c/busses/i2c-designware-core.h b/drivers/i2c/busses/i2c-designware-core.h
index d66b6cb..7a0a56e 100644
--- a/drivers/i2c/busses/i2c-designware-core.h
+++ b/drivers/i2c/busses/i2c-designware-core.h
@@ -105,6 +105,7 @@ struct dw_i2c_dev {
 	u16			ss_lcnt;
 	u16			fs_hcnt;
 	u16			fs_lcnt;
+	u32			vendor;
 };
 
 #define ACCESS_SWAP		0x00000001
diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c
index bc87733..f0556c4 100644
--- a/drivers/i2c/busses/i2c-designware-platdrv.c
+++ b/drivers/i2c/busses/i2c-designware-platdrv.c
@@ -43,16 +43,26 @@
 #include <linux/acpi.h>
 #include "i2c-designware-core.h"
 
+#define AMD_CLK_KHZ		(133 * 1000)
+#define AMD_I2C_ACPI_ID		"AMD0010"
+#define VENDOR_ID_AMD		0x1022
+
 static struct i2c_algorithm i2c_dw_algo = {
 	.master_xfer	= i2c_dw_xfer,
 	.functionality	= i2c_dw_func,
 };
+
 static u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev)
 {
 	return clk_get_rate(dev->clk)/1000;
 }
 
 #ifdef CONFIG_ACPI
+static u32 i2c_amd_get_clk_rate_khz(struct dw_i2c_dev *dev)
+{
+	return AMD_CLK_KHZ;
+}
+
 static void dw_i2c_acpi_params(struct platform_device *pdev, char method[],
 			       u16 *hcnt, u16 *lcnt, u32 *sda_hold)
 {
@@ -107,6 +117,7 @@ static const struct acpi_device_id dw_i2c_acpi_match[] = {
 	{ "INT3433", 0 },
 	{ "80860F41", 0 },
 	{ "808622C1", 0 },
+	{ AMD_I2C_ACPI_ID, 0 },
 	{ }
 };
 MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match);
@@ -134,6 +145,9 @@ static int dw_i2c_probe(struct platform_device *pdev)
 	if (!dev)
 		return -ENOMEM;
 
+	if (!strncmp(AMD_I2C_ACPI_ID, pdev->name, strlen(AMD_I2C_ACPI_ID)))
+		dev->vendor = VENDOR_ID_AMD;
+
 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	dev->base = devm_ioremap_resource(&pdev->dev, mem);
 	if (IS_ERR(dev->base))
@@ -145,12 +159,15 @@ static int dw_i2c_probe(struct platform_device *pdev)
 	dev->irq = irq;
 	platform_set_drvdata(pdev, dev);
 
-	dev->clk = devm_clk_get(&pdev->dev, NULL);
-	dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;
+	if (dev->vendor != VENDOR_ID_AMD) {
+		dev->clk = devm_clk_get(&pdev->dev, NULL);
+		dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;
 
-	if (IS_ERR(dev->clk))
-		return PTR_ERR(dev->clk);
-	clk_prepare_enable(dev->clk);
+		if (IS_ERR(dev->clk))
+			return PTR_ERR(dev->clk);
+		clk_prepare_enable(dev->clk);
+	} else
+		dev->get_clk_rate_khz = i2c_amd_get_clk_rate_khz;
 
 	if (pdev->dev.of_node) {
 		u32 ht = 0;
@@ -255,7 +272,9 @@ static int dw_i2c_suspend(struct device *dev)
 	struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
 
 	i2c_dw_disable(i_dev);
-	clk_disable_unprepare(i_dev->clk);
+
+	if (i_dev->vendor != VENDOR_ID_AMD)
+		clk_disable_unprepare(i_dev->clk);
 
 	return 0;
 }
@@ -265,7 +284,9 @@ static int dw_i2c_resume(struct device *dev)
 	struct platform_device *pdev = to_platform_device(dev);
 	struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
 
-	clk_prepare_enable(i_dev->clk);
+	if (i_dev->vendor != VENDOR_ID_AMD)
+		clk_prepare_enable(i_dev->clk);
+
 	i2c_dw_init(i_dev);
 
 	return 0;
-- 
1.9.1