mfd: Convert wm8350 physical I/O to regmap API

The driver still uses a custom cache implementation but the underlying
physical I/O is now done using the regmap API, saving some code and
avoiding allocating enormous scratch arrays on the stack.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

3 files changed, 27 insertions, 66 deletions

diff --git a/drivers/mfd/wm8350-core.c b/drivers/mfd/wm8350-core.c
index dd1caaac55e4..8a9b11ca076a 100644
--- a/drivers/mfd/wm8350-core.c
+++ b/drivers/mfd/wm8350-core.c
@@ -20,6 +20,7 @@
 #include <linux/device.h>
 #include <linux/delay.h>
 #include <linux/interrupt.h>
+#include <linux/regmap.h>
 #include <linux/workqueue.h>
 
 #include <linux/mfd/wm8350/core.h>
@@ -74,7 +75,7 @@ static int wm8350_phys_read(struct wm8350 *wm8350, u8 reg, int num_regs,
         int bytes = num_regs * 2;
 
         dev_dbg(wm8350->dev, "volatile read\n");
-        ret = wm8350->read_dev(wm8350, reg, bytes, (char *)dest);
+        ret = regmap_raw_read(wm8350->regmap, reg, dest, bytes);
 
         for (i = reg; i < reg + num_regs; i++) {
                 /* Cache is CPU endian */
@@ -96,9 +97,6 @@ static int wm8350_read(struct wm8350 *wm8350, u8 reg, int num_regs, u16 *dest)
         int ret = 0;
         int bytes = num_regs * 2;
 
-        if (wm8350->read_dev == NULL)
-                return -ENODEV;
-
         if ((reg + num_regs - 1) > WM8350_MAX_REGISTER) {
                 dev_err(wm8350->dev, "invalid reg %x\n",
                         reg + num_regs - 1);
@@ -149,9 +147,6 @@ static int wm8350_write(struct wm8350 *wm8350, u8 reg, int num_regs, u16 *src)
         int end = reg + num_regs;
         int bytes = num_regs * 2;
 
-        if (wm8350->write_dev == NULL)
-                return -ENODEV;
-
         if ((reg + num_regs - 1) > WM8350_MAX_REGISTER) {
                 dev_err(wm8350->dev, "invalid reg %x\n",
                         reg + num_regs - 1);
@@ -182,7 +177,7 @@ static int wm8350_write(struct wm8350 *wm8350, u8 reg, int num_regs, u16 *src)
         }
 
         /* Actually write it out */
-        return wm8350->write_dev(wm8350, reg, bytes, (char *)src);
+        return regmap_raw_write(wm8350->regmap, reg, src, bytes);
 }
 
 /*
@@ -515,9 +510,8 @@ static int wm8350_create_cache(struct wm8350 *wm8350, int type, int mode)
          * a PMIC so the device many not be in a virgin state and we
          * can't rely on the silicon values.
          */
-        ret = wm8350->read_dev(wm8350, 0,
-                               sizeof(u16) * (WM8350_MAX_REGISTER + 1),
-                               wm8350->reg_cache);
+        ret = regmap_raw_read(wm8350->regmap, 0, wm8350->reg_cache,
+                              sizeof(u16) * (WM8350_MAX_REGISTER + 1));
         if (ret < 0) {
                 dev_err(wm8350->dev,
                         "failed to read initial cache values\n");
@@ -570,35 +564,30 @@ int wm8350_device_init(struct wm8350 *wm8350, int irq,
                        struct wm8350_platform_data *pdata)
 {
         int ret;
-        u16 id1, id2, mask_rev;
-        u16 cust_id, mode, chip_rev;
+        unsigned int id1, id2, mask_rev;
+        unsigned int cust_id, mode, chip_rev;
 
         dev_set_drvdata(wm8350->dev, wm8350);
 
         /* get WM8350 revision and config mode */
-        ret = wm8350->read_dev(wm8350, WM8350_RESET_ID, sizeof(id1), &id1);
+        ret = regmap_read(wm8350->regmap, WM8350_RESET_ID, &id1);
         if (ret != 0) {
                 dev_err(wm8350->dev, "Failed to read ID: %d\n", ret);
                 goto err;
         }
 
-        ret = wm8350->read_dev(wm8350, WM8350_ID, sizeof(id2), &id2);
+        ret = regmap_read(wm8350->regmap, WM8350_ID, &id2);
         if (ret != 0) {
                 dev_err(wm8350->dev, "Failed to read ID: %d\n", ret);
                 goto err;
         }
 
-        ret = wm8350->read_dev(wm8350, WM8350_REVISION, sizeof(mask_rev),
-                               &mask_rev);
+        ret = regmap_read(wm8350->regmap, WM8350_REVISION, &mask_rev);
         if (ret != 0) {
                 dev_err(wm8350->dev, "Failed to read revision: %d\n", ret);
                 goto err;
         }
 
-        id1 = be16_to_cpu(id1);
-        id2 = be16_to_cpu(id2);
-        mask_rev = be16_to_cpu(mask_rev);
-
         if (id1 != 0x6143) {
                 dev_err(wm8350->dev,
                         "Device with ID %x is not a WM8350\n", id1);
diff --git a/drivers/mfd/wm8350-i2c.c b/drivers/mfd/wm8350-i2c.c
index d955faaf27c4..271589f8e8e3 100644
--- a/drivers/mfd/wm8350-i2c.c
+++ b/drivers/mfd/wm8350-i2c.c
@@ -15,47 +15,18 @@
 
 #include <linux/module.h>
 #include <linux/moduleparam.h>
+#include <linux/err.h>
 #include <linux/init.h>
 #include <linux/i2c.h>
 #include <linux/platform_device.h>
 #include <linux/mfd/wm8350/core.h>
+#include <linux/regmap.h>
 #include <linux/slab.h>
 
-static int wm8350_i2c_read_device(struct wm8350 *wm8350, char reg,
-                                  int bytes, void *dest)
-{
-        int ret;
-
-        ret = i2c_master_send(wm8350->i2c_client, &reg, 1);
-        if (ret < 0)
-                return ret;
-        ret = i2c_master_recv(wm8350->i2c_client, dest, bytes);
-        if (ret < 0)
-                return ret;
-        if (ret != bytes)
-                return -EIO;
-        return 0;
-}
-
-static int wm8350_i2c_write_device(struct wm8350 *wm8350, char reg,
-                                   int bytes, void *src)
-{
-        /* we add 1 byte for device register */
-        u8 msg[(WM8350_MAX_REGISTER << 1) + 1];
-        int ret;
-
-        if (bytes > ((WM8350_MAX_REGISTER << 1) + 1))
-                return -EINVAL;
-
-        msg[0] = reg;
-        memcpy(&msg[1], src, bytes);
-        ret = i2c_master_send(wm8350->i2c_client, msg, bytes + 1);
-        if (ret < 0)
-                return ret;
-        if (ret != bytes + 1)
-                return -EIO;
-        return 0;
-}
+static const struct regmap_config wm8350_regmap = {
+        .reg_bits = 8,
+        .val_bits = 16,
+};
 
 static int wm8350_i2c_probe(struct i2c_client *i2c,
                             const struct i2c_device_id *id)
@@ -67,11 +38,16 @@ static int wm8350_i2c_probe(struct i2c_client *i2c,
         if (wm8350 == NULL)
                 return -ENOMEM;
 
+        wm8350->regmap = devm_regmap_init_i2c(i2c, &wm8350_regmap);
+        if (IS_ERR(wm8350->regmap)) {
+                ret = PTR_ERR(wm8350->regmap);
+                dev_err(&i2c->dev, "Failed to allocate register map: %d\n",
+                        ret);
+                return ret;
+        }
+
         i2c_set_clientdata(i2c, wm8350);
         wm8350->dev = &i2c->dev;
-        wm8350->i2c_client = i2c;
-        wm8350->read_dev = wm8350_i2c_read_device;
-        wm8350->write_dev = wm8350_i2c_write_device;
 
         ret = wm8350_device_init(wm8350, i2c->irq, i2c->dev.platform_data);
         if (ret < 0)
@@ -80,6 +56,7 @@ static int wm8350_i2c_probe(struct i2c_client *i2c,
         return ret;
 
 err:
+        regmap_exit(wm8350->regmap);
         return ret;
 }
 
diff --git a/include/linux/mfd/wm8350/core.h b/include/linux/mfd/wm8350/core.h
index 98fcc977e82b..9192b6404a73 100644
--- a/include/linux/mfd/wm8350/core.h
+++ b/include/linux/mfd/wm8350/core.h
@@ -602,6 +602,7 @@ extern const u16 wm8352_mode2_defaults[];
 extern const u16 wm8352_mode3_defaults[];
 
 struct wm8350;
+struct regmap;
 
 struct wm8350_hwmon {
         struct platform_device *pdev;
@@ -612,13 +613,7 @@ struct wm8350 {
         struct device *dev;
 
         /* device IO */
-        union {
-                struct i2c_client *i2c_client;
-                struct spi_device *spi_device;
-        };
-        int (*read_dev)(struct wm8350 *wm8350, char reg, int size, void *dest);
-        int (*write_dev)(struct wm8350 *wm8350, char reg, int size,
-                         void *src);
+        struct regmap *regmap;
         u16 *reg_cache;
 
         struct mutex auxadc_mutex;