mfd/ab8500: add 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.

Cc: 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>
Change-Id: I87be719fd88c71356bb7b67374f957205b9e00fe
Reviewed-on: http://gerrit.lud.stericsson.com/gerrit/47740
Reviewed-by: Linus WALLEIJ <linus.walleij@stericsson.com>
Tested-by: Linus WALLEIJ <linus.walleij@stericsson.com>

2 files changed, 55 insertions, 23 deletions

diff --git a/drivers/mfd/ab8500-core.c b/drivers/mfd/ab8500-core.c
index 8f35a4862e3..6b197fa900a 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
@@ -108,6 +109,13 @@ 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;
@@ -260,9 +268,12 @@ 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;
@@ -315,8 +326,11 @@ 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,
@@ -867,7 +881,7 @@ 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;
@@ -880,25 +894,29 @@ 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
@@ -922,9 +940,12 @@ 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,
diff --git a/drivers/mfd/ab8500-i2c.c b/drivers/mfd/ab8500-i2c.c
index e05836723ac..1c0d1fbdb2a 100644
--- a/drivers/mfd/ab8500-i2c.c
+++ b/drivers/mfd/ab8500-i2c.c
@@ -39,6 +39,7 @@ static int ab8500_i2c_read(struct ab8500 *ab8500, u16 addr)
 
 static int __devinit ab8500_i2c_probe(struct platform_device *plf)
 {
+	const struct platform_device_id *platid = platform_get_device_id(plf);
 	struct ab8500 *ab8500;
 	struct resource *resource;
 	int ret;
@@ -62,10 +63,11 @@ static int __devinit ab8500_i2c_probe(struct platform_device *plf)
 
 	platform_set_drvdata(plf, ab8500);
 
-	ret = ab8500_init(ab8500);
+	ret = ab8500_init(ab8500, platid->driver_data);
 	if (ret)
 		kfree(ab8500);
 
+
 	return ret;
 }
 
@@ -79,13 +81,22 @@ static int __devexit ab8500_i2c_remove(struct platform_device *plf)
 	return 0;
 }
 
+static const struct platform_device_id ab8500_id[] = {
+	{ "ab8500-i2c", AB8500_VERSION_AB8500 },
+	{ "ab8505-i2c", AB8500_VERSION_AB8505 },
+	{ "ab9540-i2c", AB8500_VERSION_AB9540 },
+	{ "ab8540-i2c", AB8500_VERSION_AB8540 },
+	{ }
+};
+
 static struct platform_driver ab8500_i2c_driver = {
 	.driver = {
 		.name = "ab8500-i2c",
 		.owner = THIS_MODULE,
 	},
 	.probe	= ab8500_i2c_probe,
-	.remove	= __devexit_p(ab8500_i2c_remove)
+	.remove	= __devexit_p(ab8500_i2c_remove),
+	.id_table = ab8500_id,
 };
 
 static int __init ab8500_i2c_init(void)