mfd: Add regmap cache support for wm8350

Use the most simple possible transformation on the existing code so keep
the table sitting around, further patches in this series will delete the
existing cache code - the main purpose of this patch is to ensure that
we always have a cache for bisection.

Signed-off-by: Mark Brown <[e-mail]>
Signed-off-by: Samuel Ortiz <[e-mail]>

drivers/mfd/wm8350-core.c

···
 #include <linux/mfd/wm8350/supply.h>
 #include <linux/mfd/wm8350/wdt.h>
 
-#define WM8350_UNLOCK_KEY		0x0013
-#define WM8350_LOCK_KEY			0x0000
-
 #define WM8350_CLOCK_CONTROL_1		0x28
 #define WM8350_AIF_TEST			0x74
 
···
  */
 int wm8350_reg_lock(struct wm8350 *wm8350)
 {
-	u16 key = WM8350_LOCK_KEY;
 	int ret;
 
+	mutex_lock(&reg_lock_mutex);
+
 	ldbg(__func__);
-	mutex_lock(&io_mutex);
-	ret = wm8350_write(wm8350, WM8350_SECURITY, 1, &key);
+
+	ret = wm8350_reg_write(wm8350, WM8350_SECURITY, WM8350_LOCK_KEY);
 	if (ret)
 		dev_err(wm8350->dev, "lock failed\n");
-	mutex_unlock(&io_mutex);
+
+	wm8350->unlocked = false;
+
+	mutex_unlock(&reg_lock_mutex);
+
 	return ret;
 }
 EXPORT_SYMBOL_GPL(wm8350_reg_lock);
···
  */
 int wm8350_reg_unlock(struct wm8350 *wm8350)
 {
-	u16 key = WM8350_UNLOCK_KEY;
 	int ret;
 
+	mutex_lock(&reg_lock_mutex);
+
 	ldbg(__func__);
-	mutex_lock(&io_mutex);
-	ret = wm8350_write(wm8350, WM8350_SECURITY, 1, &key);
+
+	ret = wm8350_reg_write(wm8350, WM8350_SECURITY, WM8350_UNLOCK_KEY);
 	if (ret)
 		dev_err(wm8350->dev, "unlock failed\n");
-	mutex_unlock(&io_mutex);
+
+	wm8350->unlocked = true;
+
+	mutex_unlock(&reg_lock_mutex);
+
 	return ret;
 }
 EXPORT_SYMBOL_GPL(wm8350_reg_unlock);

drivers/mfd/wm8350-i2c.c

···
 #include <linux/regmap.h>
 #include <linux/slab.h>
 
-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)
 {

drivers/mfd/wm8350-regmap.c

···
 	{ 0x0000, 0x0000, 0x0000 }, /* R254 */
 	{ 0x0000, 0x0000, 0x0000 }, /* R255 */
 };
+
+static bool wm8350_readable(struct device *dev, unsigned int reg)
+{
+	return wm8350_reg_io_map[reg].readable;
+}
+
+static bool wm8350_writeable(struct device *dev, unsigned int reg)
+{
+	struct wm8350 *wm8350 = dev_get_drvdata(dev);
+
+	if (!wm8350->unlocked) {
+		if ((reg >= WM8350_GPIO_FUNCTION_SELECT_1 &&
+		     reg <= WM8350_GPIO_FUNCTION_SELECT_4) ||
+		    (reg >= WM8350_BATTERY_CHARGER_CONTROL_1 &&
+		     reg <= WM8350_BATTERY_CHARGER_CONTROL_3))
+			return false;
+	}
+
+	return wm8350_reg_io_map[reg].writable;
+}
+
+static bool wm8350_volatile(struct device *dev, unsigned int reg)
+{
+	return wm8350_reg_io_map[reg].vol;
+}
+
+static bool wm8350_precious(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case WM8350_SYSTEM_INTERRUPTS:
+	case WM8350_INT_STATUS_1:
+	case WM8350_INT_STATUS_2:
+	case WM8350_POWER_UP_INT_STATUS:
+	case WM8350_UNDER_VOLTAGE_INT_STATUS:
+	case WM8350_OVER_CURRENT_INT_STATUS:
+	case WM8350_GPIO_INT_STATUS:
+	case WM8350_COMPARATOR_INT_STATUS:
+		return true;
+
+	default:
+		return false;
+	}
+}
+
+const struct regmap_config wm8350_regmap = {
+	.reg_bits = 8,
+	.val_bits = 16,
+
+	.cache_type = REGCACHE_RBTREE,
+
+	.max_register = WM8350_MAX_REGISTER,
+	.readable_reg = wm8350_readable,
+	.writeable_reg = wm8350_writeable,
+	.volatile_reg = wm8350_volatile,
+	.precious_reg = wm8350_precious,
+};

include/linux/mfd/wm8350/core.h

···
 #include <linux/mutex.h>
 #include <linux/interrupt.h>
 #include <linux/completion.h>
+#include <linux/regmap.h>
 
 #include <linux/mfd/wm8350/audio.h>
 #include <linux/mfd/wm8350/gpio.h>
···
 #define WM8350_STATE_MACHINE_STATUS		0xE9
 
 #define WM8350_MAX_REGISTER                     0xFF
+
+#define WM8350_UNLOCK_KEY		0x0013
+#define WM8350_LOCK_KEY			0x0000
 
 /*
  * Field Definitions.
···
 
 #define WM8350_NUM_IRQ_REGS 7
 
+extern const struct regmap_config wm8350_regmap;
 struct wm8350_reg_access {
 	u16 readable;		/* Mask of readable bits */
 	u16 writable;		/* Mask of writable bits */
···
 extern const u16 wm8352_mode3_defaults[];
 
 struct wm8350;
-struct regmap;
 
 struct wm8350_hwmon {
 	struct platform_device *pdev;
···
 	/* device IO */
 	struct regmap *regmap;
 	u16 *reg_cache;
+	bool unlocked;
 
 	struct mutex auxadc_mutex;
 	struct completion auxadc_done;