mfd: Support 88pm8606 in 860x driver

88PM8606 and 88PM8607 are two discrete chips used for power management.
Hardware designer can use them together or only one of them according to
requirement.

There's some logic tightly linked between these two chips. For example, USB
charger driver needs to access both chips by I2C interface.

Now share one driver to these two devices. Only one I2C client is identified
in platform init data. If another chip is also used, user should mark it in
companion_addr field of platform init data. Then driver could create another
I2C client for the companion chip.

All I2C operations are accessed by 860x-i2c driver. In order to support both
I2C client address, the read/write API is changed in below.

reg_read(client, offset)
reg_write(client, offset, data)

The benefit is that client drivers only need one kind of read/write API. I2C
and MFD driver can be shared in both 8606 and 8607.

Since API is changed, update API in 8607 regulator driver.

Signed-off-by: Haojian Zhuang <haojian.zhuang@marvell.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

1 files changed, 119 insertions, 53 deletions

diff --git a/drivers/mfd/88pm860x-i2c.c b/drivers/mfd/88pm860x-i2c.c
index dda23cbfe415..6d7dba2bce8a 100644
--- a/drivers/mfd/88pm860x-i2c.c
+++ b/drivers/mfd/88pm860x-i2c.c
@@ -1,5 +1,5 @@
 /*
- * I2C driver for Marvell 88PM8607
+ * I2C driver for Marvell 88PM860x
  *
  * Copyright (C) 2009 Marvell International Ltd.
  *      Haojian Zhuang <haojian.zhuang@marvell.com>
@@ -12,12 +12,11 @@
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/i2c.h>
-#include <linux/mfd/88pm8607.h>
+#include <linux/mfd/88pm860x.h>
 
-static inline int pm8607_read_device(struct pm8607_chip *chip,
+static inline int pm860x_read_device(struct i2c_client *i2c,
                                      int reg, int bytes, void *dest)
 {
-        struct i2c_client *i2c = chip->client;
         unsigned char data;
         int ret;
 
@@ -32,10 +31,9 @@ static inline int pm8607_read_device(struct pm8607_chip *chip,
         return 0;
 }
 
-static inline int pm8607_write_device(struct pm8607_chip *chip,
+static inline int pm860x_write_device(struct i2c_client *i2c,
                                       int reg, int bytes, void *src)
 {
-        struct i2c_client *i2c = chip->client;
         unsigned char buf[bytes + 1];
         int ret;
 
@@ -48,13 +46,14 @@ static inline int pm8607_write_device(struct pm8607_chip *chip,
         return 0;
 }
 
-int pm8607_reg_read(struct pm8607_chip *chip, int reg)
+int pm860x_reg_read(struct i2c_client *i2c, int reg)
 {
+        struct pm860x_chip *chip = i2c_get_clientdata(i2c);
         unsigned char data;
         int ret;
 
         mutex_lock(&chip->io_lock);
-        ret = chip->read(chip, reg, 1, &data);
+        ret = pm860x_read_device(i2c, reg, 1, &data);
         mutex_unlock(&chip->io_lock);
 
         if (ret < 0)
@@ -62,111 +61,178 @@ int pm8607_reg_read(struct pm8607_chip *chip, int reg)
         else
                 return (int)data;
 }
-EXPORT_SYMBOL(pm8607_reg_read);
+EXPORT_SYMBOL(pm860x_reg_read);
 
-int pm8607_reg_write(struct pm8607_chip *chip, int reg,
+int pm860x_reg_write(struct i2c_client *i2c, int reg,
                      unsigned char data)
 {
+        struct pm860x_chip *chip = i2c_get_clientdata(i2c);
         int ret;
 
         mutex_lock(&chip->io_lock);
-        ret = chip->write(chip, reg, 1, &data);
+        ret = pm860x_write_device(i2c, reg, 1, &data);
         mutex_unlock(&chip->io_lock);
 
         return ret;
 }
-EXPORT_SYMBOL(pm8607_reg_write);
+EXPORT_SYMBOL(pm860x_reg_write);
 
-int pm8607_bulk_read(struct pm8607_chip *chip, int reg,
+int pm860x_bulk_read(struct i2c_client *i2c, int reg,
                      int count, unsigned char *buf)
 {
+        struct pm860x_chip *chip = i2c_get_clientdata(i2c);
         int ret;
 
         mutex_lock(&chip->io_lock);
-        ret = chip->read(chip, reg, count, buf);
+        ret = pm860x_read_device(i2c, reg, count, buf);
         mutex_unlock(&chip->io_lock);
 
         return ret;
 }
-EXPORT_SYMBOL(pm8607_bulk_read);
+EXPORT_SYMBOL(pm860x_bulk_read);
 
-int pm8607_bulk_write(struct pm8607_chip *chip, int reg,
+int pm860x_bulk_write(struct i2c_client *i2c, int reg,
                       int count, unsigned char *buf)
 {
+        struct pm860x_chip *chip = i2c_get_clientdata(i2c);
         int ret;
 
         mutex_lock(&chip->io_lock);
-        ret = chip->write(chip, reg, count, buf);
+        ret = pm860x_write_device(i2c, reg, count, buf);
         mutex_unlock(&chip->io_lock);
 
         return ret;
 }
-EXPORT_SYMBOL(pm8607_bulk_write);
+EXPORT_SYMBOL(pm860x_bulk_write);
 
-int pm8607_set_bits(struct pm8607_chip *chip, int reg,
+int pm860x_set_bits(struct i2c_client *i2c, int reg,
                     unsigned char mask, unsigned char data)
 {
+        struct pm860x_chip *chip = i2c_get_clientdata(i2c);
         unsigned char value;
         int ret;
 
         mutex_lock(&chip->io_lock);
-        ret = chip->read(chip, reg, 1, &value);
+        ret = pm860x_read_device(i2c, reg, 1, &value);
         if (ret < 0)
                 goto out;
         value &= ~mask;
         value |= data;
-        ret = chip->write(chip, reg, 1, &value);
+        ret = pm860x_write_device(i2c, reg, 1, &value);
 out:
         mutex_unlock(&chip->io_lock);
         return ret;
 }
-EXPORT_SYMBOL(pm8607_set_bits);
+EXPORT_SYMBOL(pm860x_set_bits);
 
 
 static const struct i2c_device_id pm860x_id_table[] = {
-        { "88PM8607", 0 },
+        { "88PM860x", 0 },
         {}
 };
 MODULE_DEVICE_TABLE(i2c, pm860x_id_table);
 
+static int verify_addr(struct i2c_client *i2c)
+{
+        unsigned short addr_8607[] = {0x30, 0x34};
+        unsigned short addr_8606[] = {0x10, 0x11};
+        int size, i;
+
+        if (i2c == NULL)
+                return 0;
+        size = ARRAY_SIZE(addr_8606);
+        for (i = 0; i < size; i++) {
+                if (i2c->addr == *(addr_8606 + i))
+                        return CHIP_PM8606;
+        }
+        size = ARRAY_SIZE(addr_8607);
+        for (i = 0; i < size; i++) {
+                if (i2c->addr == *(addr_8607 + i))
+                        return CHIP_PM8607;
+        }
+        return 0;
+}
+
 static int __devinit pm860x_probe(struct i2c_client *client,
                                   const struct i2c_device_id *id)
 {
-        struct pm8607_platform_data *pdata = client->dev.platform_data;
-        struct pm8607_chip *chip;
-        int ret;
-
-        chip = kzalloc(sizeof(struct pm8607_chip), GFP_KERNEL);
-        if (chip == NULL)
-                return -ENOMEM;
-
-        chip->client = client;
-        chip->dev = &client->dev;
-        chip->read = pm8607_read_device;
-        chip->write = pm8607_write_device;
-        memcpy(&chip->id, id, sizeof(struct i2c_device_id));
-        i2c_set_clientdata(client, chip);
-
-        mutex_init(&chip->io_lock);
-        dev_set_drvdata(chip->dev, chip);
-
-        ret = pm860x_device_init(chip, pdata);
-        if (ret < 0)
-                goto out;
-
-
+        struct pm860x_platform_data *pdata = client->dev.platform_data;
+        static struct pm860x_chip *chip;
+        struct i2c_board_info i2c_info = {
+                .type           = "88PM860x",
+                .platform_data  = client->dev.platform_data,
+        };
+        int addr_c, found_companion = 0;
+
+        if (pdata == NULL) {
+                pr_info("No platform data in %s!\n", __func__);
+                return -EINVAL;
+        }
+
+        /*
+         * Both client and companion client shares same platform driver.
+         * Driver distinguishes them by pdata->companion_addr.
+         * pdata->companion_addr is only assigned if companion chip exists.
+         * At the same time, the companion_addr shouldn't equal to client
+         * address.
+         */
+        addr_c = pdata->companion_addr;
+        if (addr_c && (addr_c != client->addr)) {
+                i2c_info.addr = addr_c;
+                found_companion = 1;
+        }
+
+        if (found_companion || (addr_c == 0)) {
+                chip = kzalloc(sizeof(struct pm860x_chip), GFP_KERNEL);
+                if (chip == NULL)
+                        return -ENOMEM;
+
+                chip->id = verify_addr(client);
+                chip->companion_addr = addr_c;
+                chip->client = client;
+                i2c_set_clientdata(client, chip);
+                chip->dev = &client->dev;
+                mutex_init(&chip->io_lock);
+                dev_set_drvdata(chip->dev, chip);
+
+                if (found_companion) {
+                        /*
+                         * If this driver is built in, probe function is
+                         * recursive.
+                         * If this driver is built as module, the next probe
+                         * function is called after the first one finished.
+                         */
+                        chip->companion = i2c_new_device(client->adapter,
+                                                         &i2c_info);
+                }
+        }
+
+        /*
+         * If companion chip existes, it's called by companion probe.
+         * If there's no companion chip, it's called by client probe.
+         */
+        if ((addr_c == 0) || (addr_c == client->addr)) {
+                chip->companion = client;
+                i2c_set_clientdata(chip->companion, chip);
+                pm860x_device_init(chip, pdata);
+        }
         return 0;
-
-out:
-        i2c_set_clientdata(client, NULL);
-        kfree(chip);
-        return ret;
 }
 
 static int __devexit pm860x_remove(struct i2c_client *client)
 {
-        struct pm8607_chip *chip = i2c_get_clientdata(client);
-
+        struct pm860x_chip *chip = i2c_get_clientdata(client);
+
+        /*
+         * If companion existes, companion client is removed first.
+         * Because companion client is registered last and removed first.
+         */
+        if (chip->companion_addr == client->addr)
+                return 0;
+        pm860x_device_exit(chip);
+        i2c_unregister_device(chip->companion);
+        i2c_set_clientdata(chip->companion, NULL);
+        i2c_set_clientdata(chip->client, NULL);
         kfree(chip);
         return 0;
 }