mfd: Add ab8500 version detection and enforcing

There are currently four different versions of the AB8500
around: AB8500, AB8505, AB9540 and AB8540. Unfortunately:

- Some of the chips (AB8500, AB8505, AB9540) cannot read
  the AB8500_REV_REG register but return errors

- Some of them have the same ID value in the hardware
  register AB8500_REV_REV, for example the first versions
  of AB8505 and AB9540 have 0xFF in this register -
  just like the AB8500.

So we need to be able to enforce a certain version from
the platform. We do this by using the id of the platform
device that provides the read/write functions.

Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Maxime Coquelin <maxime.coquelin@stericsson.com>
Signed-off-by: Alex Macro <alex.macro@stericsson.com>
Signed-off-by: Michel Jaouen <michel.jaouen@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

1 files changed, 42 insertions, 21 deletions

diff --git a/drivers/mfd/ab8500-core.c b/drivers/mfd/ab8500-core.c
index d295941c9a3d..3547eee21aa4 100644
--- a/drivers/mfd/ab8500-core.c
+++ b/drivers/mfd/ab8500-core.c
@@ -90,6 +90,7 @@
 #define AB8500_IT_MASK24_REG            0x57
 
 #define AB8500_REV_REG                  0x80
+#define AB8500_IC_NAME_REG              0x82
 #define AB8500_SWITCH_OFF_STATUS        0x00
 
 #define AB8500_TURN_ON_STATUS           0x00
@@ -105,6 +106,13 @@ static const int ab8500_irq_regoffset[AB8500_NUM_IRQ_REGS] = {
         0, 1, 2, 3, 4, 6, 7, 8, 9, 11, 18, 19, 20, 21,
 };
 
+static const char ab8500_version_str[][7] = {
+        [AB8500_VERSION_AB8500] = "AB8500",
+        [AB8500_VERSION_AB8505] = "AB8505",
+        [AB8500_VERSION_AB9540] = "AB9540",
+        [AB8500_VERSION_AB8540] = "AB8540",
+};
+
 static int ab8500_get_chip_id(struct device *dev)
 {
         struct ab8500 *ab8500;
@@ -256,9 +264,12 @@ static void ab8500_irq_sync_unlock(struct irq_data *data)
                 if (new == old)
                         continue;
 
-                /* Interrupt register 12 doesn't exist prior to version 2.0 */
-                if (ab8500_irq_regoffset[i] == 11 &&
-                        ab8500->chip_id < AB8500_CUT2P0)
+                /*
+                 * Interrupt register 12 doesn't exist prior to AB8500 version
+                 * 2.0
+                 */
+                if (ab8500->irq_reg_offset[i] == 11 &&
+                        is_ab8500_1p1_or_earlier(ab8500))
                         continue;
 
                 ab8500->oldmask[i] = new;
@@ -311,8 +322,11 @@ static irqreturn_t ab8500_irq(int irq, void *dev)
                 int status;
                 u8 value;
 
-                /* Interrupt register 12 doesn't exist prior to version 2.0 */
-                if (regoffset == 11 && ab8500->chip_id < AB8500_CUT2P0)
+                /*
+                 * Interrupt register 12 doesn't exist prior to AB8500 version
+                 * 2.0
+                 */
+                if (regoffset == 11 && is_ab8500_1p1_or_earlier(ab8500))
                         continue;
 
                 status = get_register_interruptible(ab8500, AB8500_INTERRUPT,
@@ -857,7 +871,7 @@ static struct attribute_group ab8500_attr_group = {
         .attrs  = ab8500_sysfs_entries,
 };
 
-int __devinit ab8500_init(struct ab8500 *ab8500)
+int __devinit ab8500_init(struct ab8500 *ab8500, enum ab8500_version version)
 {
         struct ab8500_platform_data *plat = dev_get_platdata(ab8500->dev);
         int ret;
@@ -870,25 +884,29 @@ int __devinit ab8500_init(struct ab8500 *ab8500)
         mutex_init(&ab8500->lock);
         mutex_init(&ab8500->irq_lock);
 
+        if (version != AB8500_VERSION_UNDEFINED)
+                ab8500->version = version;
+        else {
+                ret = get_register_interruptible(ab8500, AB8500_MISC,
+                        AB8500_IC_NAME_REG, &value);
+                if (ret < 0)
+                        return ret;
+
+                ab8500->version = value;
+        }
+
         ret = get_register_interruptible(ab8500, AB8500_MISC,
                 AB8500_REV_REG, &value);
         if (ret < 0)
                 return ret;
 
-        switch (value) {
-        case AB8500_CUT1P0:
-        case AB8500_CUT1P1:
-        case AB8500_CUT2P0:
-        case AB8500_CUT3P0:
-        case AB8500_CUT3P3:
-                dev_info(ab8500->dev, "detected chip, revision: %#x\n", value);
-                break;
-        default:
-                dev_err(ab8500->dev, "unknown chip, revision: %#x\n", value);
-                return -EINVAL;
-        }
         ab8500->chip_id = value;
 
+        dev_info(ab8500->dev, "detected chip, %s rev. %1x.%1x\n",
+                        ab8500_version_str[ab8500->version],
+                        ab8500->chip_id >> 4,
+                        ab8500->chip_id & 0x0F);
+
         /*
          * ab8500 has switched off due to (SWITCH_OFF_STATUS):
          * 0x01 Swoff bit programming
@@ -912,9 +930,12 @@ int __devinit ab8500_init(struct ab8500 *ab8500)
 
         /* Clear and mask all interrupts */
         for (i = 0; i < AB8500_NUM_IRQ_REGS; i++) {
-                /* Interrupt register 12 doesn't exist prior to version 2.0 */
-                if (ab8500_irq_regoffset[i] == 11 &&
-                        ab8500->chip_id < AB8500_CUT2P0)
+                /*
+                 * Interrupt register 12 doesn't exist prior to AB8500 version
+                 * 2.0
+                 */
+                if (ab8500->irq_reg_offset[i] == 11 &&
+                                is_ab8500_1p1_or_earlier(ab8500))
                         continue;
 
                 get_register_interruptible(ab8500, AB8500_INTERRUPT,