text: /*
   * Driver for TWL4030/6030 Generic Pulse Width Modulator
   *
   * Copyright (C) 2012 Texas Instruments
   * Author: Peter Ujfalusi <peter.ujfalusi@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/of.h>
  #include <linux/platform_device.h>
  #include <linux/pwm.h>
  #include <linux/mfd/twl.h>
  #include <linux/slab.h>
  
  /*
   * This driver handles the PWMs of TWL4030 and TWL6030.
   * The TRM names for the PWMs on TWL4030 are: PWM0, PWM1
   * TWL6030 also have two PWMs named in the TRM as PWM1, PWM2
   */
  
  #define TWL_PWM_MAX		0x7f
  
  /* Registers, bits and macro for TWL4030 */
  #define TWL4030_GPBR1_REG	0x0c
  #define TWL4030_PMBR1_REG	0x0d
  
  /* GPBR1 register bits */
  #define TWL4030_PWMXCLK_ENABLE	(1 << 0)
  #define TWL4030_PWMX_ENABLE	(1 << 2)
  #define TWL4030_PWMX_BITS	(TWL4030_PWMX_ENABLE | TWL4030_PWMXCLK_ENABLE)
  #define TWL4030_PWM_TOGGLE(pwm, x)	((x) << (pwm))
  
  /* PMBR1 register bits */
  #define TWL4030_GPIO6_PWM0_MUTE_MASK		(0x03 << 2)
  #define TWL4030_GPIO6_PWM0_MUTE_PWM0		(0x01 << 2)
  #define TWL4030_GPIO7_VIBRASYNC_PWM1_MASK	(0x03 << 4)
  #define TWL4030_GPIO7_VIBRASYNC_PWM1_PWM1	(0x03 << 4)
  
  /* Register, bits and macro for TWL6030 */
  #define TWL6030_TOGGLE3_REG	0x92
  
  #define TWL6030_PWMXR		(1 << 0)
  #define TWL6030_PWMXS		(1 << 1)
  #define TWL6030_PWMXEN		(1 << 2)
  #define TWL6030_PWM_TOGGLE(pwm, x)	((x) << (pwm * 3))
  
  struct twl_pwm_chip {
  	struct pwm_chip chip;
  	struct mutex mutex;
  	u8 twl6030_toggle3;
  	u8 twl4030_pwm_mux;
  };
  
  static inline struct twl_pwm_chip *to_twl(struct pwm_chip *chip)
  {
  	return container_of(chip, struct twl_pwm_chip, chip);
  }
  
  static int twl_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
  			      int duty_ns, int period_ns)
  {
  	int duty_cycle = DIV_ROUND_UP(duty_ns * TWL_PWM_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 > TWL_PWM_MAX)
  		duty_cycle = 1;
  
  	base = pwm->hwpwm * 3;
  
  	pwm_config[1] = duty_cycle;
  
  	ret = twl_i2c_write(TWL_MODULE_PWM, pwm_config, base, 2);
  	if (ret < 0)
  		dev_err(chip->dev, "%s: Failed to configure PWM\n", pwm->label);
  
  	return ret;
  }
  
  static int twl4030_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
  {
  	struct twl_pwm_chip *twl = to_twl(chip);
  	int ret;
  	u8 val;
  
  	mutex_lock(&twl->mutex);
  	ret = twl_i2c_read_u8(TWL4030_MODULE_INTBR, &val, TWL4030_GPBR1_REG);
  	if (ret < 0) {
  		dev_err(chip->dev, "%s: Failed to read GPBR1\n", pwm->label);
  		goto out;
  	}
  
  	val |= TWL4030_PWM_TOGGLE(pwm->hwpwm, TWL4030_PWMXCLK_ENABLE);
  
  	ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_GPBR1_REG);
  	if (ret < 0)
  		dev_err(chip->dev, "%s: Failed to enable PWM\n", pwm->label);
  
  	val |= TWL4030_PWM_TOGGLE(pwm->hwpwm, TWL4030_PWMX_ENABLE);
  
  	ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_GPBR1_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_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
  {
  	struct twl_pwm_chip *twl = to_twl(chip);
  	int ret;
  	u8 val;
  
  	mutex_lock(&twl->mutex);
  	ret = twl_i2c_read_u8(TWL4030_MODULE_INTBR, &val, TWL4030_GPBR1_REG);
  	if (ret < 0) {
  		dev_err(chip->dev, "%s: Failed to read GPBR1\n", pwm->label);
  		goto out;
  	}
  
  	val &= ~TWL4030_PWM_TOGGLE(pwm->hwpwm, TWL4030_PWMX_ENABLE);
  
  	ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_GPBR1_REG);
  	if (ret < 0)
  		dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);
  
  	val &= ~TWL4030_PWM_TOGGLE(pwm->hwpwm, TWL4030_PWMXCLK_ENABLE);
  
  	ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_GPBR1_REG);
  	if (ret < 0)
  		dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);
  
  out:
  	mutex_unlock(&twl->mutex);
  }
  
  static int twl4030_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
  {
  	struct twl_pwm_chip *twl = to_twl(chip);
  	int ret;
  	u8 val, mask, bits;
  
  	if (pwm->hwpwm == 1) {
  		mask = TWL4030_GPIO7_VIBRASYNC_PWM1_MASK;
  		bits = TWL4030_GPIO7_VIBRASYNC_PWM1_PWM1;
  	} else {
  		mask = TWL4030_GPIO6_PWM0_MUTE_MASK;
  		bits = TWL4030_GPIO6_PWM0_MUTE_PWM0;
  	}
  
  	mutex_lock(&twl->mutex);
  	ret = twl_i2c_read_u8(TWL4030_MODULE_INTBR, &val, TWL4030_PMBR1_REG);
  	if (ret < 0) {
  		dev_err(chip->dev, "%s: Failed to read PMBR1\n", pwm->label);
  		goto out;
  	}
  
  	/* Save the current MUX configuration for the PWM */
  	twl->twl4030_pwm_mux &= ~mask;
  	twl->twl4030_pwm_mux |= (val & mask);
  
  	/* Select PWM functionality */
  	val &= ~mask;
  	val |= bits;
  
  	ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_PMBR1_REG);
  	if (ret < 0)
  		dev_err(chip->dev, "%s: Failed to request PWM\n", pwm->label);
  
  out:
  	mutex_unlock(&twl->mutex);
  	return ret;
  }
  
  static void twl4030_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
  {
  	struct twl_pwm_chip *twl = to_twl(chip);
  	int ret;
  	u8 val, mask;
  
  	if (pwm->hwpwm == 1)
  		mask = TWL4030_GPIO7_VIBRASYNC_PWM1_MASK;
  	else
  		mask = TWL4030_GPIO6_PWM0_MUTE_MASK;
  
  	mutex_lock(&twl->mutex);
  	ret = twl_i2c_read_u8(TWL4030_MODULE_INTBR, &val, TWL4030_PMBR1_REG);
  	if (ret < 0) {
  		dev_err(chip->dev, "%s: Failed to read PMBR1\n", pwm->label);
  		goto out;
  	}
  
  	/* Restore the MUX configuration for the PWM */
  	val &= ~mask;
  	val |= (twl->twl4030_pwm_mux & mask);
  
  	ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_PMBR1_REG);
  	if (ret < 0)
  		dev_err(chip->dev, "%s: Failed to free PWM\n", pwm->label);
  
  out:
  	mutex_unlock(&twl->mutex);
  }
  
  static int twl6030_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
  {
  	struct twl_pwm_chip *twl = to_twl(chip);
  	int ret;
  	u8 val;
  
  	mutex_lock(&twl->mutex);
  	val = twl->twl6030_toggle3;
  	val |= TWL6030_PWM_TOGGLE(pwm->hwpwm, TWL6030_PWMXS | TWL6030_PWMXEN);
  	val &= ~TWL6030_PWM_TOGGLE(pwm->hwpwm, TWL6030_PWMXR);
  
  	ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_TOGGLE3_REG);
  	if (ret < 0) {
  		dev_err(chip->dev, "%s: Failed to enable PWM\n", pwm->label);
  		goto out;
  	}
  
  	twl->twl6030_toggle3 = val;
  out:
  	mutex_unlock(&twl->mutex);
  	return ret;
  }
  
  static void twl6030_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
  {
  	struct twl_pwm_chip *twl = to_twl(chip);
  	int ret;
  	u8 val;
  
  	mutex_lock(&twl->mutex);
  	val = twl->twl6030_toggle3;
  	val |= TWL6030_PWM_TOGGLE(pwm->hwpwm, TWL6030_PWMXR);
  	val &= ~TWL6030_PWM_TOGGLE(pwm->hwpwm, TWL6030_PWMXS | TWL6030_PWMXEN);
  
  	ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_TOGGLE3_REG);
  	if (ret < 0) {
  		dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);
  		goto out;
  	}
  
  	val |= TWL6030_PWM_TOGGLE(pwm->hwpwm, TWL6030_PWMXEN);
  
  	ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_TOGGLE3_REG);
  	if (ret < 0) {
  		dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);
  		goto out;
  	}
  
  	val &= ~TWL6030_PWM_TOGGLE(pwm->hwpwm, TWL6030_PWMXEN);
  
  	ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_TOGGLE3_REG);
  	if (ret < 0) {
  		dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);
  		goto out;
  	}
  
  	twl->twl6030_toggle3 = val;
  out:
  	mutex_unlock(&twl->mutex);
  }
  
  static const struct pwm_ops twl4030_pwm_ops = {
  	.config = twl_pwm_config,
  	.enable = twl4030_pwm_enable,
  	.disable = twl4030_pwm_disable,
  	.request = twl4030_pwm_request,
  	.free = twl4030_pwm_free,
  	.owner = THIS_MODULE,
  };
  
  static const struct pwm_ops twl6030_pwm_ops = {
  	.config = twl_pwm_config,
  	.enable = twl6030_pwm_enable,
  	.disable = twl6030_pwm_disable,
  	.owner = THIS_MODULE,
  };
  
  static int twl_pwm_probe(struct platform_device *pdev)
  {
  	struct twl_pwm_chip *twl;
  	int ret;
  
  	twl = devm_kzalloc(&pdev->dev, sizeof(*twl), GFP_KERNEL);
  	if (!twl)
  		return -ENOMEM;
  
  	if (twl_class_is_4030())
  		twl->chip.ops = &twl4030_pwm_ops;
  	else
  		twl->chip.ops = &twl6030_pwm_ops;
  
  	twl->chip.dev = &pdev->dev;
  	twl->chip.base = -1;
  	twl->chip.npwm = 2;
  
  	mutex_init(&twl->mutex);
  
  	ret = pwmchip_add(&twl->chip);
  	if (ret < 0)
  		return ret;
  
  	platform_set_drvdata(pdev, twl);
  
  	return 0;
  }
  
  static int twl_pwm_remove(struct platform_device *pdev)
  {
  	struct twl_pwm_chip *twl = platform_get_drvdata(pdev);
  
  	return pwmchip_remove(&twl->chip);
  }
  
  #ifdef CONFIG_OF
  static const struct of_device_id twl_pwm_of_match[] = {
  	{ .compatible = "ti,twl4030-pwm" },
  	{ .compatible = "ti,twl6030-pwm" },
  	{ },
  };
  MODULE_DEVICE_TABLE(of, twl_pwm_of_match);
  #endif
  
  static struct platform_driver twl_pwm_driver = {
  	.driver = {
  		.name = "twl-pwm",
  		.of_match_table = of_match_ptr(twl_pwm_of_match),
  	},
  	.probe = twl_pwm_probe,
  	.remove = twl_pwm_remove,
  };
  module_platform_driver(twl_pwm_driver);
  
  MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@ti.com>");
  MODULE_DESCRIPTION("PWM driver for TWL4030 and TWL6030");
  MODULE_ALIAS("platform:twl-pwm");
  MODULE_LICENSE("GPL");
  