mfd: AB8500 register access via PRCMU I2C

This patch adds the choice of accessing the AB8500 registers
via prcmu I2C. Access either via SPI or I2C is supported.

Signed-off-by: Mattias Wallin <mattias.wallin@stericsson.com>
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

4 files changed, 121 insertions, 4 deletions

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index e310cb26f52..01c928bca09 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -475,14 +475,25 @@ config EZX_PCAP
 
 config AB8500_CORE
         bool "ST-Ericsson AB8500 Mixed Signal Power Management chip"
-        depends on SPI=y && GENERIC_HARDIRQS && ABX500_CORE
+        depends on GENERIC_HARDIRQS && ABX500_CORE && SPI_MASTER
         select MFD_CORE
         help
           Select this option to enable access to AB8500 power management
-          chip. This connects to U8500 on the SSP/SPI bus and exports
-          read/write functions for the devices to get access to this chip.
+          chip. This connects to U8500 either on the SSP/SPI bus
+          or the I2C bus via PRCMU. It also adds the irq_chip
+          parts for handling the Mixed Signal chip events.
           This chip embeds various other multimedia funtionalities as well.
 
+config AB8500_I2C_CORE
+        bool "AB8500 register access via PRCMU I2C"
+        depends on AB8500_CORE && UX500_SOC_DB8500
+        default y
+        help
+          This enables register access to the AB8500 chip via PRCMU I2C.
+          The AB8500 chip can be accessed via SPI or I2C. On DB8500 hardware
+          the I2C bus is connected to the Power Reset
+          and Mangagement Unit, PRCMU.
+
 config AB8500_DEBUG
        bool "Enable debug info via debugfs"
        depends on AB8500_CORE && DEBUG_FS
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index f771c52c40d..d5968cd9304 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -69,6 +69,7 @@ obj-$(CONFIG_AB3100_CORE)	+= ab3100-core.o
 obj-$(CONFIG_AB3100_OTP)        += ab3100-otp.o
 obj-$(CONFIG_AB3550_CORE)       += ab3550-core.o
 obj-$(CONFIG_AB8500_CORE)       += ab8500-core.o ab8500-spi.o
+obj-$(CONFIG_AB8500_I2C_CORE)   += ab8500-i2c.o
 obj-$(CONFIG_AB8500_DEBUG)      += ab8500-debugfs.o
 obj-$(CONFIG_MFD_TIMBERDALE)    += timberdale.o
 obj-$(CONFIG_PMIC_ADP5520)      += adp5520.o
diff --git a/drivers/mfd/ab8500-i2c.c b/drivers/mfd/ab8500-i2c.c
new file mode 100644
index 00000000000..6820327adf4
--- /dev/null
+++ b/drivers/mfd/ab8500-i2c.c
@@ -0,0 +1,105 @@
+/*
+ * Copyright (C) ST-Ericsson SA 2010
+ * Author: Mattias Wallin <mattias.wallin@stericsson.com> for ST-Ericsson.
+ * License Terms: GNU General Public License v2
+ * This file was based on drivers/mfd/ab8500-spi.c
+ */
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/mfd/ab8500.h>
+
+#include <mach/prcmu.h>
+
+static int ab8500_i2c_write(struct ab8500 *ab8500, u16 addr, u8 data)
+{
+        int ret;
+
+        ret = prcmu_abb_write((u8)(addr >> 8), (u8)(addr & 0xFF), &data, 1);
+        if (ret < 0)
+                dev_err(ab8500->dev, "prcmu i2c error %d\n", ret);
+        return ret;
+}
+
+static int ab8500_i2c_read(struct ab8500 *ab8500, u16 addr)
+{
+        int ret;
+        u8 data;
+
+        ret = prcmu_abb_read((u8)(addr >> 8), (u8)(addr & 0xFF), &data, 1);
+        if (ret < 0) {
+                dev_err(ab8500->dev, "prcmu i2c error %d\n", ret);
+                return ret;
+        }
+        return (int)data;
+}
+
+static int __devinit ab8500_i2c_probe(struct platform_device *plf)
+{
+        struct ab8500 *ab8500;
+        struct resource *resource;
+        int ret;
+
+        ab8500 = kzalloc(sizeof *ab8500, GFP_KERNEL);
+        if (!ab8500)
+                return -ENOMEM;
+
+        ab8500->dev = &plf->dev;
+
+        resource = platform_get_resource(plf, IORESOURCE_IRQ, 0);
+        if (!resource) {
+                kfree(ab8500);
+                return -ENODEV;
+        }
+
+        ab8500->irq = resource->start;
+
+        ab8500->read = ab8500_i2c_read;
+        ab8500->write = ab8500_i2c_write;
+
+        platform_set_drvdata(plf, ab8500);
+
+        ret = ab8500_init(ab8500);
+        if (ret)
+                kfree(ab8500);
+
+        return ret;
+}
+
+static int __devexit ab8500_i2c_remove(struct platform_device *plf)
+{
+        struct ab8500 *ab8500 = platform_get_drvdata(plf);
+
+        ab8500_exit(ab8500);
+        kfree(ab8500);
+
+        return 0;
+}
+
+static struct platform_driver ab8500_i2c_driver = {
+        .driver = {
+                .name = "ab8500-i2c",
+                .owner = THIS_MODULE,
+        },
+        .probe  = ab8500_i2c_probe,
+        .remove = __devexit_p(ab8500_i2c_remove)
+};
+
+static int __init ab8500_i2c_init(void)
+{
+        return platform_driver_register(&ab8500_i2c_driver);
+}
+
+static void __exit ab8500_i2c_exit(void)
+{
+        platform_driver_unregister(&ab8500_i2c_driver);
+}
+subsys_initcall(ab8500_i2c_init);
+module_exit(ab8500_i2c_exit);
+
+MODULE_AUTHOR("Mattias WALLIN <mattias.wallin@stericsson.com");
+MODULE_DESCRIPTION("AB8500 Core access via PRCMU I2C");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/mfd/ab8500-spi.c b/drivers/mfd/ab8500-spi.c
index 01b6d584442..b1653421edb 100644
--- a/drivers/mfd/ab8500-spi.c
+++ b/drivers/mfd/ab8500-spi.c
@@ -119,7 +119,7 @@ static int __devexit ab8500_spi_remove(struct spi_device *spi)
 
 static struct spi_driver ab8500_spi_driver = {
         .driver = {
-                .name = "ab8500",
+                .name = "ab8500-spi",
                 .owner = THIS_MODULE,
         },
         .probe  = ab8500_spi_probe,