mfd: Add Qualcomm PMIC 8921 core driver

Add support for the Qualcomm PM8921 PMIC chip. The core driver
will communicate with the PMIC chip via the MSM SSBI bus.

Signed-off-by: Abhijeet Dharmapurikar <adharmap@codeaurora.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

3 files changed, 177 insertions, 0 deletions

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index ec2da8392466..d42328873dc9 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -691,6 +691,24 @@ config MFD_OMAP_USB_HOST
           This MFD driver does the required setup functionalities for
           OMAP USB Host drivers.
 
+config MFD_PM8XXX
+        tristate
+
+config MFD_PM8921_CORE
+        tristate "Qualcomm PM8921 PMIC chip"
+        depends on MSM_SSBI
+        select MFD_CORE
+        select MFD_PM8XXX
+        help
+          If you say yes to this option, support will be included for the
+          built-in PM8921 PMIC chip.
+
+          This is required if your board has a PM8921 and uses its features,
+          such as: MPPs, GPIOs, regulators, interrupts, and PWM.
+
+          Say M here if you want to include support for PM8921 chip as a module.
+          This will build a module called "pm8921-core".
+
 endif # MFD_SUPPORT
 
 menu "Multimedia Capabilities Port drivers"
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 24aa44448daf..d32a7b8f57f7 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -91,3 +91,4 @@ obj-$(CONFIG_MFD_VX855)		+= vx855.o
 obj-$(CONFIG_MFD_WL1273_CORE)   += wl1273-core.o
 obj-$(CONFIG_MFD_CS5535)        += cs5535-mfd.o
 obj-$(CONFIG_MFD_OMAP_USB_HOST) += omap-usb-host.o
+obj-$(CONFIG_MFD_PM8921_CORE)   += pm8921-core.o
diff --git a/drivers/mfd/pm8921-core.c b/drivers/mfd/pm8921-core.c
new file mode 100644
index 000000000000..a2ecd3233b1b
--- /dev/null
+++ b/drivers/mfd/pm8921-core.c
@@ -0,0 +1,158 @@
+/*
+ * Copyright (c) 2011, Code Aurora Forum. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#define pr_fmt(fmt) "%s: " fmt, __func__
+
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/msm_ssbi.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/pm8xxx/pm8921.h>
+#include <linux/mfd/pm8xxx/core.h>
+
+#define REG_HWREV               0x002  /* PMIC4 revision */
+#define REG_HWREV_2             0x0E8  /* PMIC4 revision 2 */
+
+struct pm8921 {
+        struct device                   *dev;
+};
+
+static int pm8921_readb(const struct device *dev, u16 addr, u8 *val)
+{
+        const struct pm8xxx_drvdata *pm8921_drvdata = dev_get_drvdata(dev);
+        const struct pm8921 *pmic = pm8921_drvdata->pm_chip_data;
+
+        return msm_ssbi_read(pmic->dev->parent, addr, val, 1);
+}
+
+static int pm8921_writeb(const struct device *dev, u16 addr, u8 val)
+{
+        const struct pm8xxx_drvdata *pm8921_drvdata = dev_get_drvdata(dev);
+        const struct pm8921 *pmic = pm8921_drvdata->pm_chip_data;
+
+        return msm_ssbi_write(pmic->dev->parent, addr, &val, 1);
+}
+
+static int pm8921_read_buf(const struct device *dev, u16 addr, u8 *buf,
+                                                                        int cnt)
+{
+        const struct pm8xxx_drvdata *pm8921_drvdata = dev_get_drvdata(dev);
+        const struct pm8921 *pmic = pm8921_drvdata->pm_chip_data;
+
+        return msm_ssbi_read(pmic->dev->parent, addr, buf, cnt);
+}
+
+static int pm8921_write_buf(const struct device *dev, u16 addr, u8 *buf,
+                                                                        int cnt)
+{
+        const struct pm8xxx_drvdata *pm8921_drvdata = dev_get_drvdata(dev);
+        const struct pm8921 *pmic = pm8921_drvdata->pm_chip_data;
+
+        return msm_ssbi_write(pmic->dev->parent, addr, buf, cnt);
+}
+
+static struct pm8xxx_drvdata pm8921_drvdata = {
+        .pmic_readb             = pm8921_readb,
+        .pmic_writeb            = pm8921_writeb,
+        .pmic_read_buf          = pm8921_read_buf,
+        .pmic_write_buf         = pm8921_write_buf,
+};
+
+static int __devinit pm8921_probe(struct platform_device *pdev)
+{
+        const struct pm8921_platform_data *pdata = pdev->dev.platform_data;
+        struct pm8921 *pmic;
+        int rc;
+        u8 val;
+
+        if (!pdata) {
+                pr_err("missing platform data\n");
+                return -EINVAL;
+        }
+
+        pmic = kzalloc(sizeof(struct pm8921), GFP_KERNEL);
+        if (!pmic) {
+                pr_err("Cannot alloc pm8921 struct\n");
+                return -ENOMEM;
+        }
+
+        /* Read PMIC chip revision */
+        rc = msm_ssbi_read(pdev->dev.parent, REG_HWREV, &val, sizeof(val));
+        if (rc) {
+                pr_err("Failed to read hw rev reg %d:rc=%d\n", REG_HWREV, rc);
+                goto err_read_rev;
+        }
+        pr_info("PMIC revision 1: %02X\n", val);
+
+        /* Read PMIC chip revision 2 */
+        rc = msm_ssbi_read(pdev->dev.parent, REG_HWREV_2, &val, sizeof(val));
+        if (rc) {
+                pr_err("Failed to read hw rev 2 reg %d:rc=%d\n",
+                        REG_HWREV_2, rc);
+                goto err_read_rev;
+        }
+        pr_info("PMIC revision 2: %02X\n", val);
+
+        pmic->dev = &pdev->dev;
+        pm8921_drvdata.pm_chip_data = pmic;
+        platform_set_drvdata(pdev, &pm8921_drvdata);
+
+        return 0;
+
+err_read_rev:
+        kfree(pmic);
+        return rc;
+}
+
+static int __devexit pm8921_remove(struct platform_device *pdev)
+{
+        struct pm8xxx_drvdata *drvdata;
+        struct pm8921 *pmic = NULL;
+
+        drvdata = platform_get_drvdata(pdev);
+        if (drvdata)
+                pmic = drvdata->pm_chip_data;
+        if (pmic)
+                mfd_remove_devices(pmic->dev);
+        platform_set_drvdata(pdev, NULL);
+        kfree(pmic);
+
+        return 0;
+}
+
+static struct platform_driver pm8921_driver = {
+        .probe          = pm8921_probe,
+        .remove         = __devexit_p(pm8921_remove),
+        .driver         = {
+                .name   = "pm8921-core",
+                .owner  = THIS_MODULE,
+        },
+};
+
+static int __init pm8921_init(void)
+{
+        return platform_driver_register(&pm8921_driver);
+}
+subsys_initcall(pm8921_init);
+
+static void __exit pm8921_exit(void)
+{
+        platform_driver_unregister(&pm8921_driver);
+}
+module_exit(pm8921_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("PMIC 8921 core driver");
+MODULE_VERSION("1.0");
+MODULE_ALIAS("platform:pm8921-core");