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path: root/drivers/mfd/twl6030-pwm.c
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Diffstat (limited to 'drivers/mfd/twl6030-pwm.c')
-rw-r--r--drivers/mfd/twl6030-pwm.c163
1 files changed, 163 insertions, 0 deletions
diff --git a/drivers/mfd/twl6030-pwm.c b/drivers/mfd/twl6030-pwm.c
new file mode 100644
index 00000000000..5d25bdc7842
--- /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);