1 From 9de00286e20a5f5edc419698373010f1cb6ff0ce Mon Sep 17 00:00:00 2001
2 From: John Crispin <blogic@openwrt.org>
3 Date: Sun, 27 Jul 2014 09:25:02 +0100
4 Subject: [PATCH 19/57] MIPS: ralink: add pseudo pwm led trigger based on
7 Signed-off-by: John Crispin <blogic@openwrt.org>
9 arch/mips/ralink/timer.c | 213 ++++++++++++++++++++++++++++++++++++++++++----
10 1 file changed, 197 insertions(+), 16 deletions(-)
12 diff --git a/arch/mips/ralink/timer.c b/arch/mips/ralink/timer.c
13 index e38692a..a71a7cb 100644
14 --- a/arch/mips/ralink/timer.c
15 +++ b/arch/mips/ralink/timer.c
17 #include <linux/timer.h>
18 #include <linux/of_gpio.h>
19 #include <linux/clk.h>
20 +#include <linux/leds.h>
21 +#include <linux/slab.h>
23 #include <asm/mach-ralink/ralink_regs.h>
27 #define TMR0CTL_ENABLE BIT(7)
28 #define TMR0CTL_MODE_PERIODIC BIT(4)
29 -#define TMR0CTL_PRESCALER 1
30 +#define TMR0CTL_PRESCALER 2
31 #define TMR0CTL_PRESCALE_VAL (0xf - TMR0CTL_PRESCALER)
32 #define TMR0CTL_PRESCALE_DIV (65536 / BIT(TMR0CTL_PRESCALER))
34 +struct rt_timer_gpio {
35 + struct list_head list;
36 + struct led_classdev *led;
41 - void __iomem *membase;
43 - unsigned long timer_freq;
44 - unsigned long timer_div;
46 + void __iomem *membase;
49 + unsigned long timer_freq;
50 + unsigned long timer_div;
52 + struct list_head gpios;
53 + struct led_trigger led_trigger;
54 + unsigned int duty_cycle;
58 + unsigned int fade_min;
59 + unsigned int fade_max;
60 + unsigned int fade_speed;
61 + unsigned int fade_dir;
62 + unsigned int fade_count;
65 static inline void rt_timer_w32(struct rt_timer *rt, u8 reg, u32 val)
66 @@ -48,18 +68,46 @@ static inline u32 rt_timer_r32(struct rt_timer *rt, u8 reg)
67 static irqreturn_t rt_timer_irq(int irq, void *_rt)
69 struct rt_timer *rt = (struct rt_timer *) _rt;
70 + struct rt_timer_gpio *gpio;
73 - rt_timer_w32(rt, TIMER_REG_TMR0LOAD, rt->timer_freq / rt->timer_div);
74 + if (rt->fade && (rt->fade_count++ > rt->fade_speed)) {
76 + if (rt->duty_cycle <= rt->fade_min)
78 + else if (rt->duty_cycle >= rt->fade_max)
82 + rt->duty_cycle += 1;
84 + rt->duty_cycle -= 1;
88 + val = rt->timer_freq / rt->timer_div;
90 + val *= rt->duty_cycle;
92 + val *= (100 - rt->duty_cycle);
95 + if (!list_empty(&rt->gpios))
96 + list_for_each_entry(gpio, &rt->gpios, list)
97 + led_set_brightness(gpio->led, !!rt->duty);
99 + rt->duty = !rt->duty;
101 + rt_timer_w32(rt, TIMER_REG_TMR0LOAD, val + 1);
102 rt_timer_w32(rt, TIMER_REG_TMRSTAT, TMRSTAT_TMR0INT);
108 static int rt_timer_request(struct rt_timer *rt)
110 - int err = request_irq(rt->irq, rt_timer_irq, IRQF_DISABLED,
111 - dev_name(rt->dev), rt);
112 + int err = devm_request_irq(rt->dev, rt->irq, rt_timer_irq,
113 + IRQF_DISABLED, dev_name(rt->dev), rt);
115 dev_err(rt->dev, "failed to request irq\n");
117 @@ -81,8 +129,6 @@ static int rt_timer_config(struct rt_timer *rt, unsigned long divisor)
119 rt->timer_div = divisor;
121 - rt_timer_w32(rt, TIMER_REG_TMR0LOAD, rt->timer_freq / rt->timer_div);
126 @@ -108,11 +154,128 @@ static void rt_timer_disable(struct rt_timer *rt)
127 rt_timer_w32(rt, TIMER_REG_TMR0CTL, t);
130 +static ssize_t led_fade_show(struct device *dev,
131 + struct device_attribute *attr, char *buf)
133 + struct led_classdev *led_cdev = dev_get_drvdata(dev);
134 + struct rt_timer *rt = container_of(led_cdev->trigger, struct rt_timer, led_trigger);
136 + return sprintf(buf, "speed: %d, min: %d, max: %d\n", rt->fade_speed, rt->fade_min, rt->fade_max);
139 +static ssize_t led_fade_store(struct device *dev,
140 + struct device_attribute *attr, const char *buf, size_t size)
142 + struct led_classdev *led_cdev = dev_get_drvdata(dev);
143 + struct rt_timer *rt = container_of(led_cdev->trigger, struct rt_timer, led_trigger);
144 + unsigned int speed = 0, min = 0, max = 0;
145 + ssize_t ret = -EINVAL;
147 + ret = sscanf(buf, "%u %u %u", &speed, &min, &max);
150 + rt->fade_speed = speed;
151 + rt->fade_min = min;
152 + rt->fade_max = max;
161 +static DEVICE_ATTR(fade, 0644, led_fade_show, led_fade_store);
163 +static ssize_t led_duty_cycle_show(struct device *dev,
164 + struct device_attribute *attr, char *buf)
166 + struct led_classdev *led_cdev = dev_get_drvdata(dev);
167 + struct rt_timer *rt = container_of(led_cdev->trigger, struct rt_timer, led_trigger);
169 + return sprintf(buf, "%u\n", rt->duty_cycle);
172 +static ssize_t led_duty_cycle_store(struct device *dev,
173 + struct device_attribute *attr, const char *buf, size_t size)
175 + struct led_classdev *led_cdev = dev_get_drvdata(dev);
176 + struct rt_timer *rt = container_of(led_cdev->trigger, struct rt_timer, led_trigger);
177 + unsigned long state;
178 + ssize_t ret = -EINVAL;
180 + ret = kstrtoul(buf, 10, &state);
185 + rt->duty_cycle = state;
187 + rt->duty_cycle = 100;
194 +static DEVICE_ATTR(duty_cycle, 0644, led_duty_cycle_show, led_duty_cycle_store);
196 +static void rt_timer_trig_activate(struct led_classdev *led_cdev)
198 + struct rt_timer *rt = container_of(led_cdev->trigger, struct rt_timer, led_trigger);
199 + struct rt_timer_gpio *gpio_data;
202 + led_cdev->trigger_data = NULL;
203 + gpio_data = kzalloc(sizeof(*gpio_data), GFP_KERNEL);
207 + rc = device_create_file(led_cdev->dev, &dev_attr_duty_cycle);
210 + rc = device_create_file(led_cdev->dev, &dev_attr_fade);
212 + goto err_out_duty_cycle;
214 + led_cdev->activated = true;
215 + led_cdev->trigger_data = gpio_data;
216 + gpio_data->led = led_cdev;
217 + list_add(&gpio_data->list, &rt->gpios);
218 + led_cdev->trigger_data = gpio_data;
219 + rt_timer_enable(rt);
223 + device_remove_file(led_cdev->dev, &dev_attr_duty_cycle);
229 +static void rt_timer_trig_deactivate(struct led_classdev *led_cdev)
231 + struct rt_timer *rt = container_of(led_cdev->trigger, struct rt_timer, led_trigger);
232 + struct rt_timer_gpio *gpio_data = (struct rt_timer_gpio*) led_cdev->trigger_data;
234 + if (led_cdev->activated) {
235 + device_remove_file(led_cdev->dev, &dev_attr_duty_cycle);
236 + device_remove_file(led_cdev->dev, &dev_attr_fade);
237 + led_cdev->activated = false;
240 + list_del(&gpio_data->list);
241 + rt_timer_disable(rt);
242 + led_set_brightness(led_cdev, LED_OFF);
245 static int rt_timer_probe(struct platform_device *pdev)
247 struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
248 + const __be32 *divisor;
253 rt = devm_kzalloc(&pdev->dev, sizeof(*rt), GFP_KERNEL);
255 @@ -140,12 +303,29 @@ static int rt_timer_probe(struct platform_device *pdev)
259 + rt->duty_cycle = 100;
260 rt->dev = &pdev->dev;
261 platform_set_drvdata(pdev, rt);
263 - rt_timer_request(rt);
264 - rt_timer_config(rt, 2);
265 - rt_timer_enable(rt);
266 + ret = rt_timer_request(rt);
270 + divisor = of_get_property(pdev->dev.of_node, "ralink,divisor", NULL);
272 + rt_timer_config(rt, be32_to_cpu(*divisor));
274 + rt_timer_config(rt, 200);
276 + rt->led_trigger.name = "pwmtimer",
277 + rt->led_trigger.activate = rt_timer_trig_activate,
278 + rt->led_trigger.deactivate = rt_timer_trig_deactivate,
280 + ret = led_trigger_register(&rt->led_trigger);
284 + INIT_LIST_HEAD(&rt->gpios);
286 dev_info(&pdev->dev, "maximum frequency is %luHz\n", rt->timer_freq);
288 @@ -156,6 +336,7 @@ static int rt_timer_remove(struct platform_device *pdev)
290 struct rt_timer *rt = platform_get_drvdata(pdev);
292 + led_trigger_unregister(&rt->led_trigger);
293 rt_timer_disable(rt);
296 @@ -180,6 +361,6 @@ static struct platform_driver rt_timer_driver = {
298 module_platform_driver(rt_timer_driver);
300 -MODULE_DESCRIPTION("Ralink RT2880 timer");
301 +MODULE_DESCRIPTION("Ralink RT2880 timer / pseudo pwm");
302 MODULE_AUTHOR("John Crispin <blogic@openwrt.org");
303 MODULE_LICENSE("GPL");