mfd: Add support for TWL6030 PWM
authorHemanth V <hemanthv@ti.com>
Wed, 14 Jul 2010 10:04:56 +0000 (12:04 +0200)
committerSamuel Ortiz <sameo@linux.intel.com>
Thu, 12 Aug 2010 09:27:59 +0000 (11:27 +0200)
TWL6030 supports PWM (Pulse Width Modulator) which is used
to control charging LED. PWM allows for controlling brightness.
This patch implements the APIs required by leds-pwm driver.

Signed-off-by: Hemanth V <hemanthv@ti.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
drivers/mfd/Kconfig
drivers/mfd/Makefile
drivers/mfd/twl6030-pwm.c [new file with mode: 0644]

index d59334f34bf60e1806caf22324936fe9c35e2a19..23a891f396e42db2a8c60c26b13c8c20269840f8 100644 (file)
@@ -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
index 1f7077966994f819295f55da89676894957e8afd..cc7cce0976f3de0e3b810b602f9cd55ab1052266 100644 (file)
@@ -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 (file)
index 0000000..5d25bdc
--- /dev/null
@@ -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);