+++ /dev/null
-/*
- * 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 unsigned short 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,
- unsigned short 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, 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, GPIOF_DIR_OUT | !!brightness,
- 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");
projects / karo-tx-linux.git / commitdiff