[PATCH 1/2] i2c-s3c2410: Rework device type handling

[Karol Lewandowski]

Reorganize driver a bit to better handle device tree-based systems:

 - move machine type to driver's private structure instead of
   quering platform device variants in runtime

 - replace s3c24xx_i2c_type enum with plain unsigned int that can
   hold not only device type but also hw revision-specific quirks

Signed-off-by: Karol Lewandowski <k.lewandowsk at samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park at samsung.com>
---
 drivers/i2c/busses/i2c-s3c2410.c |   56 +++++++++++++------------------------
 1 files changed, 20 insertions(+), 36 deletions(-)

diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c
index 737f721..5b400c6 100644
--- a/drivers/i2c/busses/i2c-s3c2410.c
+++ b/drivers/i2c/busses/i2c-s3c2410.c
@@ -44,8 +44,12 @@
 #include <plat/regs-iic.h>
 #include <plat/iic.h>
 
-/* i2c controller state */
+/* type */
+#define TYPE_BITS		0x000000ff
+#define TYPE_S3C2410		0x00000001
+#define TYPE_S3C2440		0x00000002
 
+/* i2c controller state */
 enum s3c24xx_i2c_state {
 	STATE_IDLE,
 	STATE_START,
@@ -54,14 +58,10 @@ enum s3c24xx_i2c_state {
 	STATE_STOP
 };
 
-enum s3c24xx_i2c_type {
-	TYPE_S3C2410,
-	TYPE_S3C2440,
-};
-
 struct s3c24xx_i2c {
 	spinlock_t		lock;
 	wait_queue_head_t	wait;
+	unsigned int            type;
 	unsigned int		suspended:1;
 
 	struct i2c_msg		*msg;
@@ -88,28 +88,6 @@ struct s3c24xx_i2c {
 #endif
 };
 
-/* default platform data removed, dev should always carry data. */
-
-/* s3c24xx_i2c_is2440()
- *
- * return true is this is an s3c2440
-*/
-
-static inline int s3c24xx_i2c_is2440(struct s3c24xx_i2c *i2c)
-{
-	struct platform_device *pdev = to_platform_device(i2c->dev);
-	enum s3c24xx_i2c_type type;
-
-#ifdef CONFIG_OF
-	if (i2c->dev->of_node)
-		return of_device_is_compatible(i2c->dev->of_node,
-				"samsung,s3c2440-i2c");
-#endif
-
-	type = platform_get_device_id(pdev)->driver_data;
-	return type == TYPE_S3C2440;
-}
-
 /* s3c24xx_i2c_master_complete
  *
  * complete the message and wake up the caller, using the given return code,
@@ -676,7 +654,7 @@ static int s3c24xx_i2c_clockrate(struct s3c24xx_i2c *i2c, unsigned int *got)
 
 	writel(iiccon, i2c->regs + S3C2410_IICCON);
 
-	if (s3c24xx_i2c_is2440(i2c)) {
+	if (i2c->type & TYPE_S3C2440) {
 		unsigned long sda_delay;
 
 		if (pdata->sda_delay) {
@@ -847,6 +825,8 @@ static int s3c24xx_i2c_init(struct s3c24xx_i2c *i2c)
 }
 
 #ifdef CONFIG_OF
+static const struct of_device_id s3c24xx_i2c_match[];
+
 /* s3c24xx_i2c_parse_dt
  *
  * Parse the device tree node and retreive the platform data.
@@ -856,11 +836,16 @@ static void
 s3c24xx_i2c_parse_dt(struct device_node *np, struct s3c24xx_i2c *i2c)
 {
 	struct s3c2410_platform_i2c *pdata = i2c->pdata;
+	const struct of_device_id *match;
 
 	if (!np)
 		return;
 
 	pdata->bus_num = -1; /* i2c bus number is dynamically assigned */
+
+	match = of_match_node(&s3c24xx_i2c_match[0], np);
+	i2c->type = (unsigned int)match->data;
+
 	of_property_read_u32(np, "samsung,i2c-sda-delay", &pdata->sda_delay);
 	of_property_read_u32(np, "samsung,i2c-slave-addr", &pdata->slave_addr);
 	of_property_read_u32(np, "samsung,i2c-max-bus-freq",
@@ -906,9 +891,10 @@ static int s3c24xx_i2c_probe(struct platform_device *pdev)
 		goto err_noclk;
 	}
 
-	if (pdata)
+	if (pdata) {
 		memcpy(i2c->pdata, pdata, sizeof(*pdata));
-	else
+		i2c->type = platform_get_device_id(pdev)->driver_data;
+	} else
 		s3c24xx_i2c_parse_dt(pdev->dev.of_node, i2c);
 
 	strlcpy(i2c->adap.name, "s3c2410-i2c", sizeof(i2c->adap.name));
@@ -1123,13 +1109,11 @@ MODULE_DEVICE_TABLE(platform, s3c24xx_driver_ids);
 
 #ifdef CONFIG_OF
 static const struct of_device_id s3c24xx_i2c_match[] = {
-	{ .compatible = "samsung,s3c2410-i2c" },
-	{ .compatible = "samsung,s3c2440-i2c" },
+	{ .compatible = "samsung,s3c2410-i2c", .data = (void *)TYPE_S3C2410 },
+	{ .compatible = "samsung,s3c2440-i2c", .data = (void *)TYPE_S3C2440 },
 	{},
 };
 MODULE_DEVICE_TABLE(of, s3c24xx_i2c_match);
-#else
-#define s3c24xx_i2c_match NULL
 #endif
 
 static struct platform_driver s3c24xx_i2c_driver = {
@@ -1140,7 +1124,7 @@ static struct platform_driver s3c24xx_i2c_driver = {
 		.owner	= THIS_MODULE,
 		.name	= "s3c-i2c",
 		.pm	= S3C24XX_DEV_PM_OPS,
-		.of_match_table = s3c24xx_i2c_match,
+		.of_match_table = of_match_ptr(s3c24xx_i2c_match),
 	},
 };
 
-- 
1.7.9