diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/leds/Kconfig | 12 | ||||
| -rw-r--r-- | drivers/leds/Makefile | 1 | ||||
| -rw-r--r-- | drivers/leds/leds-renesas-tpu.c | 344 |
3 files changed, 357 insertions, 0 deletions
diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig index dc7caaddecf4..ff203a421863 100644 --- a/drivers/leds/Kconfig +++ b/drivers/leds/Kconfig @@ -375,6 +375,18 @@ config LEDS_ASIC3 cannot be used. This driver supports hardware blinking with an on+off period from 62ms to 125s. Say Y to enable LEDs on the HP iPAQ hx4700. +config LEDS_RENESAS_TPU + bool "LED support for Renesas TPU" + depends on LEDS_CLASS && HAVE_CLK && GENERIC_GPIO + help + This option enables build of the LED TPU platform driver, + suitable to drive any TPU channel on newer Renesas SoCs. + The driver controls the GPIO pin connected to the LED via + the GPIO framework and expects the LED to be connected to + a pin that can be driven in both GPIO mode and using TPU + pin function. The latter to support brightness control. + Brightness control is supported but hardware blinking is not. + config LEDS_TRIGGERS bool "LED Trigger support" depends on LEDS_CLASS diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile index a0a1b89d78a8..e4f6bf568880 100644 --- a/drivers/leds/Makefile +++ b/drivers/leds/Makefile @@ -42,6 +42,7 @@ obj-$(CONFIG_LEDS_MC13783) += leds-mc13783.o obj-$(CONFIG_LEDS_NS2) += leds-ns2.o obj-$(CONFIG_LEDS_NETXBIG) += leds-netxbig.o obj-$(CONFIG_LEDS_ASIC3) += leds-asic3.o +obj-$(CONFIG_LEDS_RENESAS_TPU) += leds-renesas-tpu.o # LED SPI Drivers obj-$(CONFIG_LEDS_DAC124S085) += leds-dac124s085.o diff --git a/drivers/leds/leds-renesas-tpu.c b/drivers/leds/leds-renesas-tpu.c new file mode 100644 index 000000000000..d9a7d72a7569 --- /dev/null +++ b/drivers/leds/leds-renesas-tpu.c @@ -0,0 +1,344 @@ +/* + * 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/leds-renesas-tpu.h> +#include <linux/gpio.h> +#include <linux/err.h> +#include <linux/slab.h> +#include <linux/pm_runtime.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; +}; + +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 = 0; k < ARRAY_SIZE(prescaler); k++) + if ((rate / prescaler[k]) < p->min_rate) + break; + + if (!k) { + dev_err(&p->pdev->dev, "clock rate mismatch\n"); + goto err0; + } + dev_dbg(&p->pdev->dev, "rate = %lu, prescaler %u\n", + rate, prescaler[k - 1]); + + /* clear TCNT on TGRB match, count on rising edge, set prescaler */ + r_tpu_write(p, TCR, 0x0040 | (k - 1)); + + /* output 0 until TGRA, output 1 until TGRB */ + r_tpu_write(p, TIOR, 0x0002); + + rate /= prescaler[k - 1] * 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(cfg->pin_gpio, cfg->name); + gpio_direction_output(cfg->pin_gpio, !!brightness); + } + 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_set_brightness(struct led_classdev *ldev, + enum led_brightness brightness) +{ + struct r_tpu_priv *p = container_of(ldev, struct r_tpu_priv, ldev); + + r_tpu_disable(p); + + /* off and maximum are handled as GPIO pins, in between PWM */ + if ((brightness == 0) || (brightness == 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 int __devinit 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 = -ENXIO; + + if (!cfg) { + dev_err(&pdev->dev, "missing platform data\n"); + goto err0; + } + + p = kzalloc(sizeof(*p), GFP_KERNEL); + if (p == NULL) { + dev_err(&pdev->dev, "failed to allocate driver data\n"); + ret = -ENOMEM; + goto err0; + } + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) { + dev_err(&pdev->dev, "failed to get I/O memory\n"); + goto err1; + } + + /* map memory, let mapbase point to our channel */ + p->mapbase = ioremap_nocache(res->start, resource_size(res)); + if (p->mapbase == NULL) { + dev_err(&pdev->dev, "failed to remap I/O memory\n"); + goto err1; + } + + /* get hold of clock */ + p->clk = clk_get(&pdev->dev, NULL); + if (IS_ERR(p->clk)) { + dev_err(&pdev->dev, "cannot get clock\n"); + ret = PTR_ERR(p->clk); + goto err2; + } + + 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); + + + 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 err3; + + /* 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; + + err3: + r_tpu_set_pin(p, R_TPU_PIN_UNUSED, LED_OFF); + clk_put(p->clk); + err2: + iounmap(p->mapbase); + err1: + kfree(p); + err0: + return ret; +} + +static int __devexit 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); + r_tpu_disable(p); + r_tpu_set_pin(p, R_TPU_PIN_UNUSED, LED_OFF); + + pm_runtime_disable(&pdev->dev); + clk_put(p->clk); + + iounmap(p->mapbase); + kfree(p); + return 0; +} + +static struct platform_driver r_tpu_device_driver = { + .probe = r_tpu_probe, + .remove = __devexit_p(r_tpu_remove), + .driver = { + .name = "leds-renesas-tpu", + } +}; + +static int __init r_tpu_init(void) +{ + return platform_driver_register(&r_tpu_device_driver); +} + +static void __exit r_tpu_exit(void) +{ + platform_driver_unregister(&r_tpu_device_driver); +} + +module_init(r_tpu_init); +module_exit(r_tpu_exit); + +MODULE_AUTHOR("Magnus Damm"); +MODULE_DESCRIPTION("Renesas TPU LED Driver"); +MODULE_LICENSE("GPL v2"); |