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Diffstat (limited to 'drivers/pwm/pwm-twl-led.c')
-rw-r--r--drivers/pwm/pwm-twl-led.c392
1 files changed, 392 insertions, 0 deletions
diff --git a/drivers/pwm/pwm-twl-led.c b/drivers/pwm/pwm-twl-led.c
new file mode 100644
index 0000000000..8fb84b4418
--- /dev/null
+++ b/drivers/pwm/pwm-twl-led.c
@@ -0,0 +1,392 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Driver for TWL4030/6030 Pulse Width Modulator used as LED driver
+ *
+ * Copyright (C) 2012 Texas Instruments
+ * Author: Peter Ujfalusi <peter.ujfalusi@ti.com>
+ *
+ * This driver is a complete rewrite of the former pwm-twl6030.c authorded by:
+ * Hemanth V <hemanthv@ti.com>
+ *
+ * Reference manual for the twl6030 is available at:
+ * https://www.ti.com/lit/ds/symlink/twl6030.pdf
+ *
+ * Limitations:
+ * - The twl6030 hardware only supports two period lengths (128 clock ticks and
+ * 64 clock ticks), the driver only uses 128 ticks
+ * - The hardware doesn't support ON = 0, so the active part of a period doesn't
+ * start at its beginning.
+ * - The hardware could support inverted polarity (with a similar limitation as
+ * for normal: the last clock tick is always inactive).
+ * - The hardware emits a constant low output when disabled.
+ * - A request for .duty_cycle = 0 results in an output wave with one active
+ * clock tick per period. This should better use the disabled state.
+ * - The driver only implements setting the relative duty cycle.
+ * - The driver doesn't implement .get_state().
+ */
+
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+#include <linux/mfd/twl.h>
+#include <linux/slab.h>
+
+/*
+ * This driver handles the PWM driven LED terminals of TWL4030 and TWL6030.
+ * To generate the signal on TWL4030:
+ * - LEDA uses PWMA
+ * - LEDB uses PWMB
+ * TWL6030 has one LED pin with dedicated LEDPWM
+ */
+
+#define TWL4030_LED_MAX 0x7f
+#define TWL6030_LED_MAX 0xff
+
+/* Registers, bits and macro for TWL4030 */
+#define TWL4030_LEDEN_REG 0x00
+#define TWL4030_PWMA_REG 0x01
+
+#define TWL4030_LEDXON (1 << 0)
+#define TWL4030_LEDXPWM (1 << 4)
+#define TWL4030_LED_PINS (TWL4030_LEDXON | TWL4030_LEDXPWM)
+#define TWL4030_LED_TOGGLE(led, x) ((x) << (led))
+
+/* Register, bits and macro for TWL6030 */
+#define TWL6030_LED_PWM_CTRL1 0xf4
+#define TWL6030_LED_PWM_CTRL2 0xf5
+
+#define TWL6040_LED_MODE_HW 0x00
+#define TWL6040_LED_MODE_ON 0x01
+#define TWL6040_LED_MODE_OFF 0x02
+#define TWL6040_LED_MODE_MASK 0x03
+
+struct twl_pwmled_chip {
+ struct pwm_chip chip;
+ struct mutex mutex;
+};
+
+static inline struct twl_pwmled_chip *to_twl(struct pwm_chip *chip)
+{
+ return container_of(chip, struct twl_pwmled_chip, chip);
+}
+
+static int twl4030_pwmled_config(struct pwm_chip *chip, struct pwm_device *pwm,
+ int duty_ns, int period_ns)
+{
+ int duty_cycle = DIV_ROUND_UP(duty_ns * TWL4030_LED_MAX, period_ns) + 1;
+ u8 pwm_config[2] = { 1, 0 };
+ int base, ret;
+
+ /*
+ * To configure the duty period:
+ * On-cycle is set to 1 (the minimum allowed value)
+ * The off time of 0 is not configurable, so the mapping is:
+ * 0 -> off cycle = 2,
+ * 1 -> off cycle = 2,
+ * 2 -> off cycle = 3,
+ * 126 - > off cycle 127,
+ * 127 - > off cycle 1
+ * When on cycle == off cycle the PWM will be always on
+ */
+ if (duty_cycle == 1)
+ duty_cycle = 2;
+ else if (duty_cycle > TWL4030_LED_MAX)
+ duty_cycle = 1;
+
+ base = pwm->hwpwm * 2 + TWL4030_PWMA_REG;
+
+ pwm_config[1] = duty_cycle;
+
+ ret = twl_i2c_write(TWL4030_MODULE_LED, pwm_config, base, 2);
+ if (ret < 0)
+ dev_err(chip->dev, "%s: Failed to configure PWM\n", pwm->label);
+
+ return ret;
+}
+
+static int twl4030_pwmled_enable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ struct twl_pwmled_chip *twl = to_twl(chip);
+ int ret;
+ u8 val;
+
+ mutex_lock(&twl->mutex);
+ ret = twl_i2c_read_u8(TWL4030_MODULE_LED, &val, TWL4030_LEDEN_REG);
+ if (ret < 0) {
+ dev_err(chip->dev, "%s: Failed to read LEDEN\n", pwm->label);
+ goto out;
+ }
+
+ val |= TWL4030_LED_TOGGLE(pwm->hwpwm, TWL4030_LED_PINS);
+
+ ret = twl_i2c_write_u8(TWL4030_MODULE_LED, val, TWL4030_LEDEN_REG);
+ if (ret < 0)
+ dev_err(chip->dev, "%s: Failed to enable PWM\n", pwm->label);
+
+out:
+ mutex_unlock(&twl->mutex);
+ return ret;
+}
+
+static void twl4030_pwmled_disable(struct pwm_chip *chip,
+ struct pwm_device *pwm)
+{
+ struct twl_pwmled_chip *twl = to_twl(chip);
+ int ret;
+ u8 val;
+
+ mutex_lock(&twl->mutex);
+ ret = twl_i2c_read_u8(TWL4030_MODULE_LED, &val, TWL4030_LEDEN_REG);
+ if (ret < 0) {
+ dev_err(chip->dev, "%s: Failed to read LEDEN\n", pwm->label);
+ goto out;
+ }
+
+ val &= ~TWL4030_LED_TOGGLE(pwm->hwpwm, TWL4030_LED_PINS);
+
+ ret = twl_i2c_write_u8(TWL4030_MODULE_LED, val, TWL4030_LEDEN_REG);
+ if (ret < 0)
+ dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);
+
+out:
+ mutex_unlock(&twl->mutex);
+}
+
+static int twl4030_pwmled_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+ const struct pwm_state *state)
+{
+ int ret;
+
+ if (state->polarity != PWM_POLARITY_NORMAL)
+ return -EINVAL;
+
+ if (!state->enabled) {
+ if (pwm->state.enabled)
+ twl4030_pwmled_disable(chip, pwm);
+
+ return 0;
+ }
+
+ /*
+ * We cannot skip calling ->config even if state->period ==
+ * pwm->state.period && state->duty_cycle == pwm->state.duty_cycle
+ * because we might have exited early in the last call to
+ * pwm_apply_state because of !state->enabled and so the two values in
+ * pwm->state might not be configured in hardware.
+ */
+ ret = twl4030_pwmled_config(pwm->chip, pwm,
+ state->duty_cycle, state->period);
+ if (ret)
+ return ret;
+
+ if (!pwm->state.enabled)
+ ret = twl4030_pwmled_enable(chip, pwm);
+
+ return ret;
+}
+
+
+static const struct pwm_ops twl4030_pwmled_ops = {
+ .apply = twl4030_pwmled_apply,
+ .owner = THIS_MODULE,
+};
+
+static int twl6030_pwmled_config(struct pwm_chip *chip, struct pwm_device *pwm,
+ int duty_ns, int period_ns)
+{
+ int duty_cycle = (duty_ns * TWL6030_LED_MAX) / period_ns;
+ u8 on_time;
+ int ret;
+
+ on_time = duty_cycle & 0xff;
+
+ ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, on_time,
+ TWL6030_LED_PWM_CTRL1);
+ if (ret < 0)
+ dev_err(chip->dev, "%s: Failed to configure PWM\n", pwm->label);
+
+ return ret;
+}
+
+static int twl6030_pwmled_enable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ struct twl_pwmled_chip *twl = to_twl(chip);
+ int ret;
+ u8 val;
+
+ mutex_lock(&twl->mutex);
+ ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);
+ if (ret < 0) {
+ dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n",
+ pwm->label);
+ goto out;
+ }
+
+ val &= ~TWL6040_LED_MODE_MASK;
+ val |= TWL6040_LED_MODE_ON;
+
+ ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);
+ if (ret < 0)
+ dev_err(chip->dev, "%s: Failed to enable PWM\n", pwm->label);
+
+out:
+ mutex_unlock(&twl->mutex);
+ return ret;
+}
+
+static void twl6030_pwmled_disable(struct pwm_chip *chip,
+ struct pwm_device *pwm)
+{
+ struct twl_pwmled_chip *twl = to_twl(chip);
+ int ret;
+ u8 val;
+
+ mutex_lock(&twl->mutex);
+ ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);
+ if (ret < 0) {
+ dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n",
+ pwm->label);
+ goto out;
+ }
+
+ val &= ~TWL6040_LED_MODE_MASK;
+ val |= TWL6040_LED_MODE_OFF;
+
+ ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);
+ if (ret < 0)
+ dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);
+
+out:
+ mutex_unlock(&twl->mutex);
+}
+
+static int twl6030_pwmled_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+ const struct pwm_state *state)
+{
+ int err;
+
+ if (state->polarity != pwm->state.polarity)
+ return -EINVAL;
+
+ if (!state->enabled) {
+ if (pwm->state.enabled)
+ twl6030_pwmled_disable(chip, pwm);
+
+ return 0;
+ }
+
+ err = twl6030_pwmled_config(pwm->chip, pwm,
+ state->duty_cycle, state->period);
+ if (err)
+ return err;
+
+ if (!pwm->state.enabled)
+ err = twl6030_pwmled_enable(chip, pwm);
+
+ return err;
+}
+
+static int twl6030_pwmled_request(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ struct twl_pwmled_chip *twl = to_twl(chip);
+ int ret;
+ u8 val;
+
+ mutex_lock(&twl->mutex);
+ ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);
+ if (ret < 0) {
+ dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n",
+ pwm->label);
+ goto out;
+ }
+
+ val &= ~TWL6040_LED_MODE_MASK;
+ val |= TWL6040_LED_MODE_OFF;
+
+ ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);
+ if (ret < 0)
+ dev_err(chip->dev, "%s: Failed to request PWM\n", pwm->label);
+
+out:
+ mutex_unlock(&twl->mutex);
+ return ret;
+}
+
+static void twl6030_pwmled_free(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ struct twl_pwmled_chip *twl = to_twl(chip);
+ int ret;
+ u8 val;
+
+ mutex_lock(&twl->mutex);
+ ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);
+ if (ret < 0) {
+ dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n",
+ pwm->label);
+ goto out;
+ }
+
+ val &= ~TWL6040_LED_MODE_MASK;
+ val |= TWL6040_LED_MODE_HW;
+
+ ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);
+ if (ret < 0)
+ dev_err(chip->dev, "%s: Failed to free PWM\n", pwm->label);
+
+out:
+ mutex_unlock(&twl->mutex);
+}
+
+static const struct pwm_ops twl6030_pwmled_ops = {
+ .apply = twl6030_pwmled_apply,
+ .request = twl6030_pwmled_request,
+ .free = twl6030_pwmled_free,
+ .owner = THIS_MODULE,
+};
+
+static int twl_pwmled_probe(struct platform_device *pdev)
+{
+ struct twl_pwmled_chip *twl;
+
+ twl = devm_kzalloc(&pdev->dev, sizeof(*twl), GFP_KERNEL);
+ if (!twl)
+ return -ENOMEM;
+
+ if (twl_class_is_4030()) {
+ twl->chip.ops = &twl4030_pwmled_ops;
+ twl->chip.npwm = 2;
+ } else {
+ twl->chip.ops = &twl6030_pwmled_ops;
+ twl->chip.npwm = 1;
+ }
+
+ twl->chip.dev = &pdev->dev;
+
+ mutex_init(&twl->mutex);
+
+ return devm_pwmchip_add(&pdev->dev, &twl->chip);
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id twl_pwmled_of_match[] = {
+ { .compatible = "ti,twl4030-pwmled" },
+ { .compatible = "ti,twl6030-pwmled" },
+ { },
+};
+MODULE_DEVICE_TABLE(of, twl_pwmled_of_match);
+#endif
+
+static struct platform_driver twl_pwmled_driver = {
+ .driver = {
+ .name = "twl-pwmled",
+ .of_match_table = of_match_ptr(twl_pwmled_of_match),
+ },
+ .probe = twl_pwmled_probe,
+};
+module_platform_driver(twl_pwmled_driver);
+
+MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@ti.com>");
+MODULE_DESCRIPTION("PWM driver for TWL4030 and TWL6030 LED outputs");
+MODULE_ALIAS("platform:twl-pwmled");
+MODULE_LICENSE("GPL");
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-19 04:07:46 +0000