drivers/leds/leds-renesas-tpu.c - kernel/msm-4.9 - Gitiles

 /*
  * LED control using Renesas TPU
  *
  *  Copyright (C) 2011 Magnus Damm
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License
  *
  * 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, write to the Free Software
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */

 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/platform_device.h>
 #include <linux/spinlock.h>
 #include <linux/printk.h>
 #include <linux/ioport.h>
 #include <linux/io.h>
 #include <linux/clk.h>
 #include <linux/leds.h>
 #include <linux/platform_data/leds-renesas-tpu.h>
 #include <linux/gpio.h>
 #include <linux/err.h>
 #include <linux/slab.h>
 #include <linux/pm_runtime.h>
 #include <linux/workqueue.h>

 enum r_tpu_pin { R_TPU_PIN_UNUSED, R_TPU_PIN_GPIO, R_TPU_PIN_GPIO_FN };
 enum r_tpu_timer { R_TPU_TIMER_UNUSED, R_TPU_TIMER_ON };

 struct r_tpu_priv {
 	struct led_classdev ldev;
 	void __iomem *mapbase;
 	struct clk *clk;
 	struct platform_device *pdev;
 	enum r_tpu_pin pin_state;
 	enum r_tpu_timer timer_state;
 	unsigned long min_rate;
 	unsigned int refresh_rate;
 	struct work_struct work;
 	enum led_brightness new_brightness;
 };

 static DEFINE_SPINLOCK(r_tpu_lock);

 #define TSTR -1 /* Timer start register (shared register) */
 #define TCR  0 /* Timer control register (+0x00) */
 #define TMDR 1 /* Timer mode register (+0x04) */
 #define TIOR 2 /* Timer I/O control register (+0x08) */
 #define TIER 3 /* Timer interrupt enable register (+0x0c) */
 #define TSR  4 /* Timer status register (+0x10) */
 #define TCNT 5 /* Timer counter (+0x14) */
 #define TGRA 6 /* Timer general register A (+0x18) */
 #define TGRB 7 /* Timer general register B (+0x1c) */
 #define TGRC 8 /* Timer general register C (+0x20) */
 #define TGRD 9 /* Timer general register D (+0x24) */

 static inline u16 r_tpu_read(struct r_tpu_priv *p, int reg_nr)
 {
 	struct led_renesas_tpu_config *cfg = p->pdev->dev.platform_data;
 	void __iomem *base = p->mapbase;
 	unsigned long offs = reg_nr << 2;

 	if (reg_nr == TSTR)
 		return ioread16(base - cfg->channel_offset);

 	return ioread16(base + offs);
 }

 static inline void r_tpu_write(struct r_tpu_priv *p, int reg_nr, u16 value)
 {
 	struct led_renesas_tpu_config *cfg = p->pdev->dev.platform_data;
 	void __iomem *base = p->mapbase;
 	unsigned long offs = reg_nr << 2;

 	if (reg_nr == TSTR) {
 		iowrite16(value, base - cfg->channel_offset);
 		return;
 	}

 	iowrite16(value, base + offs);
 }

 static void r_tpu_start_stop_ch(struct r_tpu_priv *p, int start)
 {
 	struct led_renesas_tpu_config *cfg = p->pdev->dev.platform_data;
 	unsigned long flags;
 	u16 value;

 	/* start stop register shared by multiple timer channels */
 	spin_lock_irqsave(&r_tpu_lock, flags);
 	value = r_tpu_read(p, TSTR);

 	if (start)
 		value |= 1 << cfg->timer_bit;
 	else
 		value &= ~(1 << cfg->timer_bit);

 	r_tpu_write(p, TSTR, value);
 	spin_unlock_irqrestore(&r_tpu_lock, flags);
 }

 static int r_tpu_enable(struct r_tpu_priv *p, enum led_brightness brightness)
 {
 	struct led_renesas_tpu_config *cfg = p->pdev->dev.platform_data;
 	int prescaler[] = { 1, 4, 16, 64 };
 	int k, ret;
 	unsigned long rate, tmp;

 	if (p->timer_state == R_TPU_TIMER_ON)
 		return 0;

 	/* wake up device and enable clock */
 	pm_runtime_get_sync(&p->pdev->dev);
 	ret = clk_enable(p->clk);
 	if (ret) {
 		dev_err(&p->pdev->dev, "cannot enable clock\n");
 		return ret;
 	}

 	/* make sure channel is disabled */
 	r_tpu_start_stop_ch(p, 0);

 	/* get clock rate after enabling it */
 	rate = clk_get_rate(p->clk);

 	/* pick the lowest acceptable rate */
 	for (k = ARRAY_SIZE(prescaler) - 1; k >= 0; k--)
 		if ((rate / prescaler[k]) >= p->min_rate)
 			break;

 	if (k < 0) {
 		dev_err(&p->pdev->dev, "clock rate mismatch\n");
 		goto err0;
 	}
 	dev_dbg(&p->pdev->dev, "rate = %lu, prescaler %u\n",
 		rate, prescaler[k]);

 	/* clear TCNT on TGRB match, count on rising edge, set prescaler */
 	r_tpu_write(p, TCR, 0x0040 | k);

 	/* output 0 until TGRA, output 1 until TGRB */
 	r_tpu_write(p, TIOR, 0x0002);

 	rate /= prescaler[k] * p->refresh_rate;
 	r_tpu_write(p, TGRB, rate);
 	dev_dbg(&p->pdev->dev, "TRGB = 0x%04lx\n", rate);

 	tmp = (cfg->max_brightness - brightness) * rate;
 	r_tpu_write(p, TGRA, tmp / cfg->max_brightness);
 	dev_dbg(&p->pdev->dev, "TRGA = 0x%04lx\n", tmp / cfg->max_brightness);

 	/* PWM mode */
 	r_tpu_write(p, TMDR, 0x0002);

 	/* enable channel */
 	r_tpu_start_stop_ch(p, 1);

 	p->timer_state = R_TPU_TIMER_ON;
 	return 0;
  err0:
 	clk_disable(p->clk);
 	pm_runtime_put_sync(&p->pdev->dev);
 	return -ENOTSUPP;
 }

 static void r_tpu_disable(struct r_tpu_priv *p)
 {
 	if (p->timer_state == R_TPU_TIMER_UNUSED)
 		return;

 	/* disable channel */
 	r_tpu_start_stop_ch(p, 0);

 	/* stop clock and mark device as idle */
 	clk_disable(p->clk);
 	pm_runtime_put_sync(&p->pdev->dev);

 	p->timer_state = R_TPU_TIMER_UNUSED;
 }

 static void r_tpu_set_pin(struct r_tpu_priv *p, enum r_tpu_pin new_state,
 			  enum led_brightness brightness)
 {
 	struct led_renesas_tpu_config *cfg = p->pdev->dev.platform_data;

 	if (p->pin_state == new_state) {
 		if (p->pin_state == R_TPU_PIN_GPIO)
 			gpio_set_value(cfg->pin_gpio, brightness);
 		return;
 	}

 	if (p->pin_state == R_TPU_PIN_GPIO)
 		gpio_free(cfg->pin_gpio);

 	if (p->pin_state == R_TPU_PIN_GPIO_FN)
 		gpio_free(cfg->pin_gpio_fn);

 	if (new_state == R_TPU_PIN_GPIO)
 		gpio_request_one(cfg->pin_gpio, !!brightness ?
 				GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW,
 				cfg->name);

 	if (new_state == R_TPU_PIN_GPIO_FN)
 		gpio_request(cfg->pin_gpio_fn, cfg->name);

 	p->pin_state = new_state;
 }

 static void r_tpu_work(struct work_struct *work)
 {
 	struct r_tpu_priv *p = container_of(work, struct r_tpu_priv, work);
 	enum led_brightness brightness = p->new_brightness;

 	r_tpu_disable(p);

 	/* off and maximum are handled as GPIO pins, in between PWM */
 	if ((brightness == 0) || (brightness == p->ldev.max_brightness))
 		r_tpu_set_pin(p, R_TPU_PIN_GPIO, brightness);
 	else {
 		r_tpu_set_pin(p, R_TPU_PIN_GPIO_FN, 0);
 		r_tpu_enable(p, brightness);
 	}
 }

 static void r_tpu_set_brightness(struct led_classdev *ldev,
 				 enum led_brightness brightness)
 {
 	struct r_tpu_priv *p = container_of(ldev, struct r_tpu_priv, ldev);
 	p->new_brightness = brightness;
 	schedule_work(&p->work);
 }

 static int r_tpu_probe(struct platform_device *pdev)
 {
 	struct led_renesas_tpu_config *cfg = pdev->dev.platform_data;
 	struct r_tpu_priv *p;
 	struct resource *res;
 	int ret;

 	if (!cfg) {
 		dev_err(&pdev->dev, "missing platform data\n");
 		return -ENODEV;
 	}

 	p = devm_kzalloc(&pdev->dev, sizeof(*p), GFP_KERNEL);
 	if (p == NULL) {
 		dev_err(&pdev->dev, "failed to allocate driver data\n");
 		return -ENOMEM;
 	}

 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (!res) {
 		dev_err(&pdev->dev, "failed to get I/O memory\n");
 		return -ENXIO;
 	}

 	/* map memory, let mapbase point to our channel */
 	p->mapbase = devm_ioremap_nocache(&pdev->dev, res->start,
 					resource_size(res));
 	if (p->mapbase == NULL) {
 		dev_err(&pdev->dev, "failed to remap I/O memory\n");
 		return -ENXIO;
 	}

 	/* get hold of clock */
 	p->clk = devm_clk_get(&pdev->dev, NULL);
 	if (IS_ERR(p->clk)) {
 		dev_err(&pdev->dev, "cannot get clock\n");
 		return PTR_ERR(p->clk);
 	}

 	p->pdev = pdev;
 	p->pin_state = R_TPU_PIN_UNUSED;
 	p->timer_state = R_TPU_TIMER_UNUSED;
 	p->refresh_rate = cfg->refresh_rate ? cfg->refresh_rate : 100;
 	r_tpu_set_pin(p, R_TPU_PIN_GPIO, LED_OFF);
 	platform_set_drvdata(pdev, p);

 	INIT_WORK(&p->work, r_tpu_work);

 	p->ldev.name = cfg->name;
 	p->ldev.brightness = LED_OFF;
 	p->ldev.max_brightness = cfg->max_brightness;
 	p->ldev.brightness_set = r_tpu_set_brightness;
 	p->ldev.flags |= LED_CORE_SUSPENDRESUME;
 	ret = led_classdev_register(&pdev->dev, &p->ldev);
 	if (ret < 0)
 		goto err0;

 	/* max_brightness may be updated by the LED core code */
 	p->min_rate = p->ldev.max_brightness * p->refresh_rate;

 	pm_runtime_enable(&pdev->dev);
 	return 0;

  err0:
 	r_tpu_set_pin(p, R_TPU_PIN_UNUSED, LED_OFF);
 	return ret;
 }

 static int r_tpu_remove(struct platform_device *pdev)
 {
 	struct r_tpu_priv *p = platform_get_drvdata(pdev);

 	r_tpu_set_brightness(&p->ldev, LED_OFF);
 	led_classdev_unregister(&p->ldev);
 	cancel_work_sync(&p->work);
 	r_tpu_disable(p);
 	r_tpu_set_pin(p, R_TPU_PIN_UNUSED, LED_OFF);

 	pm_runtime_disable(&pdev->dev);

 	return 0;
 }

 static struct platform_driver r_tpu_device_driver = {
 	.probe		= r_tpu_probe,
 	.remove		= r_tpu_remove,
 	.driver		= {
 		.name	= "leds-renesas-tpu",
 	}
 };

 module_platform_driver(r_tpu_device_driver);

 MODULE_AUTHOR("Magnus Damm");
 MODULE_DESCRIPTION("Renesas TPU LED Driver");
 MODULE_LICENSE("GPL v2");
	/*
	* LED control using Renesas TPU
	*
	* Copyright (C) 2011 Magnus Damm
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2 of the License
	*
	* 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, write to the Free Software
	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	*/

	#include <linux/module.h>
	#include <linux/init.h>
	#include <linux/platform_device.h>
	#include <linux/spinlock.h>
	#include <linux/printk.h>
	#include <linux/ioport.h>
	#include <linux/io.h>
	#include <linux/clk.h>
	#include <linux/leds.h>
	#include <linux/platform_data/leds-renesas-tpu.h>
	#include <linux/gpio.h>
	#include <linux/err.h>
	#include <linux/slab.h>
	#include <linux/pm_runtime.h>
	#include <linux/workqueue.h>

	enum r_tpu_pin { R_TPU_PIN_UNUSED, R_TPU_PIN_GPIO, R_TPU_PIN_GPIO_FN };
	enum r_tpu_timer { R_TPU_TIMER_UNUSED, R_TPU_TIMER_ON };

	struct r_tpu_priv {
	struct led_classdev ldev;
	void __iomem *mapbase;
	struct clk *clk;
	struct platform_device *pdev;
	enum r_tpu_pin pin_state;
	enum r_tpu_timer timer_state;
	unsigned long min_rate;
	unsigned int refresh_rate;
	struct work_struct work;
	enum led_brightness new_brightness;
	};

	static DEFINE_SPINLOCK(r_tpu_lock);

	#define TSTR -1 /* Timer start register (shared register) */
	#define TCR 0 /* Timer control register (+0x00) */
	#define TMDR 1 /* Timer mode register (+0x04) */
	#define TIOR 2 /* Timer I/O control register (+0x08) */
	#define TIER 3 /* Timer interrupt enable register (+0x0c) */
	#define TSR 4 /* Timer status register (+0x10) */
	#define TCNT 5 /* Timer counter (+0x14) */
	#define TGRA 6 /* Timer general register A (+0x18) */
	#define TGRB 7 /* Timer general register B (+0x1c) */
	#define TGRC 8 /* Timer general register C (+0x20) */
	#define TGRD 9 /* Timer general register D (+0x24) */

	static inline u16 r_tpu_read(struct r_tpu_priv *p, int reg_nr)
	{
	struct led_renesas_tpu_config *cfg = p->pdev->dev.platform_data;
	void __iomem *base = p->mapbase;
	unsigned long offs = reg_nr << 2;

	if (reg_nr == TSTR)
	return ioread16(base - cfg->channel_offset);

	return ioread16(base + offs);
	}

	static inline void r_tpu_write(struct r_tpu_priv *p, int reg_nr, u16 value)
	{
	struct led_renesas_tpu_config *cfg = p->pdev->dev.platform_data;
	void __iomem *base = p->mapbase;
	unsigned long offs = reg_nr << 2;

	if (reg_nr == TSTR) {
	iowrite16(value, base - cfg->channel_offset);
	return;
	}

	iowrite16(value, base + offs);
	}

	static void r_tpu_start_stop_ch(struct r_tpu_priv *p, int start)
	{
	struct led_renesas_tpu_config *cfg = p->pdev->dev.platform_data;
	unsigned long flags;
	u16 value;

	/* start stop register shared by multiple timer channels */
	spin_lock_irqsave(&r_tpu_lock, flags);
	value = r_tpu_read(p, TSTR);

	if (start)
	value \|= 1 << cfg->timer_bit;
	else
	value &= ~(1 << cfg->timer_bit);

	r_tpu_write(p, TSTR, value);
	spin_unlock_irqrestore(&r_tpu_lock, flags);
	}

	static int r_tpu_enable(struct r_tpu_priv *p, enum led_brightness brightness)
	{
	struct led_renesas_tpu_config *cfg = p->pdev->dev.platform_data;
	int prescaler[] = { 1, 4, 16, 64 };
	int k, ret;
	unsigned long rate, tmp;

	if (p->timer_state == R_TPU_TIMER_ON)
	return 0;

	/* wake up device and enable clock */
	pm_runtime_get_sync(&p->pdev->dev);
	ret = clk_enable(p->clk);
	if (ret) {
	dev_err(&p->pdev->dev, "cannot enable clock\n");
	return ret;
	}

	/* make sure channel is disabled */
	r_tpu_start_stop_ch(p, 0);

	/* get clock rate after enabling it */
	rate = clk_get_rate(p->clk);

	/* pick the lowest acceptable rate */
	for (k = ARRAY_SIZE(prescaler) - 1; k >= 0; k--)
	if ((rate / prescaler[k]) >= p->min_rate)
	break;

	if (k < 0) {
	dev_err(&p->pdev->dev, "clock rate mismatch\n");
	goto err0;
	}
	dev_dbg(&p->pdev->dev, "rate = %lu, prescaler %u\n",
	rate, prescaler[k]);

	/* clear TCNT on TGRB match, count on rising edge, set prescaler */
	r_tpu_write(p, TCR, 0x0040 \| k);

	/* output 0 until TGRA, output 1 until TGRB */
	r_tpu_write(p, TIOR, 0x0002);

	rate /= prescaler[k] * p->refresh_rate;
	r_tpu_write(p, TGRB, rate);
	dev_dbg(&p->pdev->dev, "TRGB = 0x%04lx\n", rate);

	tmp = (cfg->max_brightness - brightness) * rate;
	r_tpu_write(p, TGRA, tmp / cfg->max_brightness);
	dev_dbg(&p->pdev->dev, "TRGA = 0x%04lx\n", tmp / cfg->max_brightness);

	/* PWM mode */
	r_tpu_write(p, TMDR, 0x0002);

	/* enable channel */
	r_tpu_start_stop_ch(p, 1);

	p->timer_state = R_TPU_TIMER_ON;
	return 0;
	err0:
	clk_disable(p->clk);
	pm_runtime_put_sync(&p->pdev->dev);
	return -ENOTSUPP;
	}

	static void r_tpu_disable(struct r_tpu_priv *p)
	{
	if (p->timer_state == R_TPU_TIMER_UNUSED)
	return;

	/* disable channel */
	r_tpu_start_stop_ch(p, 0);

	/* stop clock and mark device as idle */
	clk_disable(p->clk);
	pm_runtime_put_sync(&p->pdev->dev);

	p->timer_state = R_TPU_TIMER_UNUSED;
	}

	static void r_tpu_set_pin(struct r_tpu_priv *p, enum r_tpu_pin new_state,
	enum led_brightness brightness)
	{
	struct led_renesas_tpu_config *cfg = p->pdev->dev.platform_data;

	if (p->pin_state == new_state) {
	if (p->pin_state == R_TPU_PIN_GPIO)
	gpio_set_value(cfg->pin_gpio, brightness);
	return;
	}

	if (p->pin_state == R_TPU_PIN_GPIO)
	gpio_free(cfg->pin_gpio);

	if (p->pin_state == R_TPU_PIN_GPIO_FN)
	gpio_free(cfg->pin_gpio_fn);

	if (new_state == R_TPU_PIN_GPIO)
	gpio_request_one(cfg->pin_gpio, !!brightness ?
	GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW,
	cfg->name);

	if (new_state == R_TPU_PIN_GPIO_FN)
	gpio_request(cfg->pin_gpio_fn, cfg->name);

	p->pin_state = new_state;
	}

	static void r_tpu_work(struct work_struct *work)
	{
	struct r_tpu_priv *p = container_of(work, struct r_tpu_priv, work);
	enum led_brightness brightness = p->new_brightness;

	r_tpu_disable(p);

	/* off and maximum are handled as GPIO pins, in between PWM */
	if ((brightness == 0) \|\| (brightness == p->ldev.max_brightness))
	r_tpu_set_pin(p, R_TPU_PIN_GPIO, brightness);
	else {
	r_tpu_set_pin(p, R_TPU_PIN_GPIO_FN, 0);
	r_tpu_enable(p, brightness);
	}
	}

	static void r_tpu_set_brightness(struct led_classdev *ldev,
	enum led_brightness brightness)
	{
	struct r_tpu_priv *p = container_of(ldev, struct r_tpu_priv, ldev);
	p->new_brightness = brightness;
	schedule_work(&p->work);
	}

	static int r_tpu_probe(struct platform_device *pdev)
	{
	struct led_renesas_tpu_config *cfg = pdev->dev.platform_data;
	struct r_tpu_priv *p;
	struct resource *res;
	int ret;

	if (!cfg) {
	dev_err(&pdev->dev, "missing platform data\n");
	return -ENODEV;
	}

	p = devm_kzalloc(&pdev->dev, sizeof(*p), GFP_KERNEL);
	if (p == NULL) {
	dev_err(&pdev->dev, "failed to allocate driver data\n");
	return -ENOMEM;
	}

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!res) {
	dev_err(&pdev->dev, "failed to get I/O memory\n");
	return -ENXIO;
	}

	/* map memory, let mapbase point to our channel */
	p->mapbase = devm_ioremap_nocache(&pdev->dev, res->start,
	resource_size(res));
	if (p->mapbase == NULL) {
	dev_err(&pdev->dev, "failed to remap I/O memory\n");
	return -ENXIO;
	}

	/* get hold of clock */
	p->clk = devm_clk_get(&pdev->dev, NULL);
	if (IS_ERR(p->clk)) {
	dev_err(&pdev->dev, "cannot get clock\n");
	return PTR_ERR(p->clk);
	}

	p->pdev = pdev;
	p->pin_state = R_TPU_PIN_UNUSED;
	p->timer_state = R_TPU_TIMER_UNUSED;
	p->refresh_rate = cfg->refresh_rate ? cfg->refresh_rate : 100;
	r_tpu_set_pin(p, R_TPU_PIN_GPIO, LED_OFF);
	platform_set_drvdata(pdev, p);

	INIT_WORK(&p->work, r_tpu_work);

	p->ldev.name = cfg->name;
	p->ldev.brightness = LED_OFF;
	p->ldev.max_brightness = cfg->max_brightness;
	p->ldev.brightness_set = r_tpu_set_brightness;
	p->ldev.flags \|= LED_CORE_SUSPENDRESUME;
	ret = led_classdev_register(&pdev->dev, &p->ldev);
	if (ret < 0)
	goto err0;

	/* max_brightness may be updated by the LED core code */
	p->min_rate = p->ldev.max_brightness * p->refresh_rate;

	pm_runtime_enable(&pdev->dev);
	return 0;

	err0:
	r_tpu_set_pin(p, R_TPU_PIN_UNUSED, LED_OFF);
	return ret;
	}

	static int r_tpu_remove(struct platform_device *pdev)
	{
	struct r_tpu_priv *p = platform_get_drvdata(pdev);

	r_tpu_set_brightness(&p->ldev, LED_OFF);
	led_classdev_unregister(&p->ldev);
	cancel_work_sync(&p->work);
	r_tpu_disable(p);
	r_tpu_set_pin(p, R_TPU_PIN_UNUSED, LED_OFF);

	pm_runtime_disable(&pdev->dev);

	return 0;
	}

	static struct platform_driver r_tpu_device_driver = {
	.probe = r_tpu_probe,
	.remove = r_tpu_remove,
	.driver = {
	.name = "leds-renesas-tpu",
	}
	};

	module_platform_driver(r_tpu_device_driver);

	MODULE_AUTHOR("Magnus Damm");
	MODULE_DESCRIPTION("Renesas TPU LED Driver");
	MODULE_LICENSE("GPL v2");