3 files changed, 173 insertions, 0 deletions

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index d59334f34bf6..23a891f396e4 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -186,6 +186,15 @@ config TWL4030_CODEC
         select MFD_CORE
         default n
 
+config TWL6030_PWM
+        tristate "TWL6030 PWM (Pulse Width Modulator) Support"
+        depends on TWL4030_CORE
+        select HAVE_PWM
+        default n
+        help
+          Say yes here if you want support for TWL6030 PWM.
+          This is used to control charging LED brightness.
+
 config MFD_STMPE
         bool "Support STMicroelectronics STMPE"
         depends on I2C=y && GENERIC_HARDIRQS
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 1f7077966994..cc7cce0976f3 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -37,6 +37,7 @@ obj-$(CONFIG_MENELAUS)		+= menelaus.o
 obj-$(CONFIG_TWL4030_CORE)      += twl-core.o twl4030-irq.o twl6030-irq.o
 obj-$(CONFIG_TWL4030_POWER)    += twl4030-power.o
 obj-$(CONFIG_TWL4030_CODEC)     += twl4030-codec.o
+obj-$(CONFIG_TWL6030_PWM)       += twl6030-pwm.o
 
 obj-$(CONFIG_MFD_MC13783)       += mc13783-core.o
 
diff --git a/drivers/mfd/twl6030-pwm.c b/drivers/mfd/twl6030-pwm.c
new file mode 100644
index 000000000000..5d25bdc78424
--- /dev/null
+++ b/drivers/mfd/twl6030-pwm.c
@@ -0,0 +1,163 @@
+/*
+ * twl6030_pwm.c
+ * Driver for PHOENIX (TWL6030) Pulse Width Modulator
+ *
+ * Copyright (C) 2010 Texas Instruments
+ * Author: Hemanth V <hemanthv@ti.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License 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.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/i2c/twl.h>
+#include <linux/slab.h>
+
+#define LED_PWM_CTRL1   0xF4
+#define LED_PWM_CTRL2   0xF5
+
+/* Max value for CTRL1 register */
+#define PWM_CTRL1_MAX   255
+
+/* Pull down disable */
+#define PWM_CTRL2_DIS_PD        (1 << 6)
+
+/* Current control 2.5 milli Amps */
+#define PWM_CTRL2_CURR_02       (2 << 4)
+
+/* LED supply source */
+#define PWM_CTRL2_SRC_VAC       (1 << 2)
+
+/* LED modes */
+#define PWM_CTRL2_MODE_HW       (0 << 0)
+#define PWM_CTRL2_MODE_SW       (1 << 0)
+#define PWM_CTRL2_MODE_DIS      (2 << 0)
+
+#define PWM_CTRL2_MODE_MASK     0x3
+
+struct pwm_device {
+        const char *label;
+        unsigned int pwm_id;
+};
+
+int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
+{
+        u8 duty_cycle;
+        int ret;
+
+        if (pwm == NULL || period_ns == 0 || duty_ns > period_ns)
+                return -EINVAL;
+
+        duty_cycle = (duty_ns * PWM_CTRL1_MAX) / period_ns;
+
+        ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, duty_cycle, LED_PWM_CTRL1);
+
+        if (ret < 0) {
+                pr_err("%s: Failed to configure PWM, Error %d\n",
+                        pwm->label, ret);
+                return ret;
+        }
+        return 0;
+}
+EXPORT_SYMBOL(pwm_config);
+
+int pwm_enable(struct pwm_device *pwm)
+{
+        u8 val;
+        int ret;
+
+        ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, LED_PWM_CTRL2);
+        if (ret < 0) {
+                pr_err("%s: Failed to enable PWM, Error %d\n", pwm->label, ret);
+                return ret;
+        }
+
+        /* Change mode to software control */
+        val &= ~PWM_CTRL2_MODE_MASK;
+        val |= PWM_CTRL2_MODE_SW;
+
+        ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, LED_PWM_CTRL2);
+        if (ret < 0) {
+                pr_err("%s: Failed to enable PWM, Error %d\n", pwm->label, ret);
+                return ret;
+        }
+
+        twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, LED_PWM_CTRL2);
+        return 0;
+}
+EXPORT_SYMBOL(pwm_enable);
+
+void pwm_disable(struct pwm_device *pwm)
+{
+        u8 val;
+        int ret;
+
+        ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, LED_PWM_CTRL2);
+        if (ret < 0) {
+                pr_err("%s: Failed to disable PWM, Error %d\n",
+                        pwm->label, ret);
+                return;
+        }
+
+        val &= ~PWM_CTRL2_MODE_MASK;
+        val |= PWM_CTRL2_MODE_HW;
+
+        ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, LED_PWM_CTRL2);
+        if (ret < 0) {
+                pr_err("%s: Failed to disable PWM, Error %d\n",
+                        pwm->label, ret);
+                return;
+        }
+        return;
+}
+EXPORT_SYMBOL(pwm_disable);
+
+struct pwm_device *pwm_request(int pwm_id, const char *label)
+{
+        u8 val;
+        int ret;
+        struct pwm_device *pwm;
+
+        pwm = kzalloc(sizeof(struct pwm_device), GFP_KERNEL);
+        if (pwm == NULL) {
+                pr_err("%s: failed to allocate memory\n", label);
+                return NULL;
+        }
+
+        pwm->label = label;
+        pwm->pwm_id = pwm_id;
+
+        /* Configure PWM */
+        val = PWM_CTRL2_DIS_PD | PWM_CTRL2_CURR_02 | PWM_CTRL2_SRC_VAC |
+                PWM_CTRL2_MODE_HW;
+
+        ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, LED_PWM_CTRL2);
+
+        if (ret < 0) {
+                pr_err("%s: Failed to configure PWM, Error %d\n",
+                         pwm->label, ret);
+
+                kfree(pwm);
+                return NULL;
+        }
+
+        return pwm;
+}
+EXPORT_SYMBOL(pwm_request);
+
+void pwm_free(struct pwm_device *pwm)
+{
+        pwm_disable(pwm);
+        kfree(pwm);
+}
+EXPORT_SYMBOL(pwm_free);