3 files changed, 163 insertions, 0 deletions

diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index 90c5c7357a50..99a738182bf5 100644
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -29,6 +29,15 @@ menuconfig PWM
 
 if PWM
 
+config PWM_AB8500
+        tristate "AB8500 PWM support"
+        depends on AB8500_CORE && ARCH_U8500
+        help
+          Generic PWM framework driver for Analog Baseband AB8500.
+
+          To compile this driver as a module, choose M here: the module
+          will be called pwm-ab8500.
+
 config PWM_BFIN
         tristate "Blackfin PWM support"
         depends on BFIN_GPTIMERS
diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile
index e4b2c898964d..bebc6ff904b9 100644
--- a/drivers/pwm/Makefile
+++ b/drivers/pwm/Makefile
@@ -1,4 +1,5 @@
 obj-$(CONFIG_PWM)               += core.o
+obj-$(CONFIG_PWM_AB8500)        += pwm-ab8500.o
 obj-$(CONFIG_PWM_BFIN)          += pwm-bfin.o
 obj-$(CONFIG_PWM_IMX)           += pwm-imx.o
 obj-$(CONFIG_PWM_LPC32XX)       += pwm-lpc32xx.o
diff --git a/drivers/pwm/pwm-ab8500.c b/drivers/pwm/pwm-ab8500.c
new file mode 100644
index 000000000000..cfb72ca873d1
--- /dev/null
+++ b/drivers/pwm/pwm-ab8500.c
@@ -0,0 +1,153 @@
+/*
+ * Copyright (C) ST-Ericsson SA 2010
+ *
+ * Author: Arun R Murthy <arun.murthy@stericsson.com>
+ * License terms: GNU General Public License (GPL) version 2
+ */
+#include <linux/err.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/pwm.h>
+#include <linux/mfd/abx500.h>
+#include <linux/mfd/abx500/ab8500.h>
+#include <linux/module.h>
+
+/*
+ * PWM Out generators
+ * Bank: 0x10
+ */
+#define AB8500_PWM_OUT_CTRL1_REG        0x60
+#define AB8500_PWM_OUT_CTRL2_REG        0x61
+#define AB8500_PWM_OUT_CTRL7_REG        0x66
+
+/* backlight driver constants */
+#define ENABLE_PWM                      1
+#define DISABLE_PWM                     0
+
+struct ab8500_pwm_chip {
+        struct pwm_chip chip;
+};
+
+static int ab8500_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
+                             int duty_ns, int period_ns)
+{
+        int ret = 0;
+        unsigned int higher_val, lower_val;
+        u8 reg;
+
+        /*
+         * get the first 8 bits that are be written to
+         * AB8500_PWM_OUT_CTRL1_REG[0:7]
+         */
+        lower_val = duty_ns & 0x00FF;
+        /*
+         * get bits [9:10] that are to be written to
+         * AB8500_PWM_OUT_CTRL2_REG[0:1]
+         */
+        higher_val = ((duty_ns & 0x0300) >> 8);
+
+        reg = AB8500_PWM_OUT_CTRL1_REG + ((chip->base - 1) * 2);
+
+        ret = abx500_set_register_interruptible(chip->dev, AB8500_MISC,
+                        reg, (u8)lower_val);
+        if (ret < 0)
+                return ret;
+        ret = abx500_set_register_interruptible(chip->dev, AB8500_MISC,
+                        (reg + 1), (u8)higher_val);
+
+        return ret;
+}
+
+static int ab8500_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+        int ret;
+
+        ret = abx500_mask_and_set_register_interruptible(chip->dev,
+                                AB8500_MISC, AB8500_PWM_OUT_CTRL7_REG,
+                                1 << (chip->base - 1), ENABLE_PWM);
+        if (ret < 0)
+                dev_err(chip->dev, "%s: Failed to disable PWM, Error %d\n",
+                                                        pwm->label, ret);
+        return ret;
+}
+
+static void ab8500_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+        int ret;
+
+        ret = abx500_mask_and_set_register_interruptible(chip->dev,
+                                AB8500_MISC, AB8500_PWM_OUT_CTRL7_REG,
+                                1 << (chip->base - 1), DISABLE_PWM);
+        if (ret < 0)
+                dev_err(chip->dev, "%s: Failed to disable PWM, Error %d\n",
+                                                        pwm->label, ret);
+        return;
+}
+
+static const struct pwm_ops ab8500_pwm_ops = {
+        .config = ab8500_pwm_config,
+        .enable = ab8500_pwm_enable,
+        .disable = ab8500_pwm_disable,
+};
+
+static int __devinit ab8500_pwm_probe(struct platform_device *pdev)
+{
+        struct ab8500_pwm_chip *ab8500;
+        int err;
+
+        /*
+         * Nothing to be done in probe, this is required to get the
+         * device which is required for ab8500 read and write
+         */
+        ab8500 = kzalloc(sizeof(*ab8500), GFP_KERNEL);
+        if (ab8500 == NULL) {
+                dev_err(&pdev->dev, "failed to allocate memory\n");
+                return -ENOMEM;
+        }
+
+        ab8500->chip.dev = &pdev->dev;
+        ab8500->chip.ops = &ab8500_pwm_ops;
+        ab8500->chip.base = pdev->id;
+        ab8500->chip.npwm = 1;
+
+        err = pwmchip_add(&ab8500->chip);
+        if (err < 0) {
+                kfree(ab8500);
+                return err;
+        }
+
+        dev_dbg(&pdev->dev, "pwm probe successful\n");
+        platform_set_drvdata(pdev, ab8500);
+
+        return 0;
+}
+
+static int __devexit ab8500_pwm_remove(struct platform_device *pdev)
+{
+        struct ab8500_pwm_chip *ab8500 = platform_get_drvdata(pdev);
+        int err;
+
+        err = pwmchip_remove(&ab8500->chip);
+        if (err < 0)
+                return err;
+
+        dev_dbg(&pdev->dev, "pwm driver removed\n");
+        kfree(ab8500);
+
+        return 0;
+}
+
+static struct platform_driver ab8500_pwm_driver = {
+        .driver = {
+                .name = "ab8500-pwm",
+                .owner = THIS_MODULE,
+        },
+        .probe = ab8500_pwm_probe,
+        .remove = __devexit_p(ab8500_pwm_remove),
+};
+module_platform_driver(ab8500_pwm_driver);
+
+MODULE_AUTHOR("Arun MURTHY <arun.murthy@stericsson.com>");
+MODULE_DESCRIPTION("AB8500 Pulse Width Modulation Driver");
+MODULE_ALIAS("platform:ab8500-pwm");
+MODULE_LICENSE("GPL v2");