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 --- a/arch/mips/ralink/timer.c
13 +++ b/arch/mips/ralink/timer.c
15 #include <linux/timer.h>
16 #include <linux/of_gpio.h>
17 #include <linux/clk.h>
18 +#include <linux/leds.h>
19 +#include <linux/slab.h>
21 #include <asm/mach-ralink/ralink_regs.h>
25 #define TMR0CTL_ENABLE BIT(7)
26 #define TMR0CTL_MODE_PERIODIC BIT(4)
27 -#define TMR0CTL_PRESCALER 1
28 +#define TMR0CTL_PRESCALER 2
29 #define TMR0CTL_PRESCALE_VAL (0xf - TMR0CTL_PRESCALER)
30 #define TMR0CTL_PRESCALE_DIV (65536 / BIT(TMR0CTL_PRESCALER))
32 +struct rt_timer_gpio {
33 + struct list_head list;
34 + struct led_classdev *led;
39 - void __iomem *membase;
41 - unsigned long timer_freq;
42 - unsigned long timer_div;
44 + void __iomem *membase;
47 + unsigned long timer_freq;
48 + unsigned long timer_div;
50 + struct list_head gpios;
51 + struct led_trigger led_trigger;
52 + unsigned int duty_cycle;
56 + unsigned int fade_min;
57 + unsigned int fade_max;
58 + unsigned int fade_speed;
59 + unsigned int fade_dir;
60 + unsigned int fade_count;
63 static inline void rt_timer_w32(struct rt_timer *rt, u8 reg, u32 val)
64 @@ -48,8 +68,37 @@ static inline u32 rt_timer_r32(struct rt
65 static irqreturn_t rt_timer_irq(int irq, void *_rt)
67 struct rt_timer *rt = (struct rt_timer *) _rt;
68 + struct rt_timer_gpio *gpio;
71 - rt_timer_w32(rt, TIMER_REG_TMR0LOAD, rt->timer_freq / rt->timer_div);
72 + if (rt->fade && (rt->fade_count++ > rt->fade_speed)) {
74 + if (rt->duty_cycle <= rt->fade_min)
76 + else if (rt->duty_cycle >= rt->fade_max)
80 + rt->duty_cycle += 1;
82 + rt->duty_cycle -= 1;
86 + val = rt->timer_freq / rt->timer_div;
88 + val *= rt->duty_cycle;
90 + val *= (100 - rt->duty_cycle);
93 + if (!list_empty(&rt->gpios))
94 + list_for_each_entry(gpio, &rt->gpios, list)
95 + led_set_brightness(gpio->led, !!rt->duty);
97 + rt->duty = !rt->duty;
99 + rt_timer_w32(rt, TIMER_REG_TMR0LOAD, val + 1);
100 rt_timer_w32(rt, TIMER_REG_TMRSTAT, TMRSTAT_TMR0INT);
103 @@ -58,8 +107,8 @@ static irqreturn_t rt_timer_irq(int irq,
105 static int rt_timer_request(struct rt_timer *rt)
107 - int err = request_irq(rt->irq, rt_timer_irq, 0,
108 - dev_name(rt->dev), rt);
109 + int err = devm_request_irq(rt->dev, rt->irq, rt_timer_irq,
110 + 0, dev_name(rt->dev), rt);
112 dev_err(rt->dev, "failed to request irq\n");
114 @@ -81,8 +130,6 @@ static int rt_timer_config(struct rt_tim
116 rt->timer_div = divisor;
118 - rt_timer_w32(rt, TIMER_REG_TMR0LOAD, rt->timer_freq / rt->timer_div);
123 @@ -108,11 +155,128 @@ static void rt_timer_disable(struct rt_t
124 rt_timer_w32(rt, TIMER_REG_TMR0CTL, t);
127 +static ssize_t led_fade_show(struct device *dev,
128 + struct device_attribute *attr, char *buf)
130 + struct led_classdev *led_cdev = dev_get_drvdata(dev);
131 + struct rt_timer *rt = container_of(led_cdev->trigger, struct rt_timer, led_trigger);
133 + return sprintf(buf, "speed: %d, min: %d, max: %d\n", rt->fade_speed, rt->fade_min, rt->fade_max);
136 +static ssize_t led_fade_store(struct device *dev,
137 + struct device_attribute *attr, const char *buf, size_t size)
139 + struct led_classdev *led_cdev = dev_get_drvdata(dev);
140 + struct rt_timer *rt = container_of(led_cdev->trigger, struct rt_timer, led_trigger);
141 + unsigned int speed = 0, min = 0, max = 0;
142 + ssize_t ret = -EINVAL;
144 + ret = sscanf(buf, "%u %u %u", &speed, &min, &max);
147 + rt->fade_speed = speed;
148 + rt->fade_min = min;
149 + rt->fade_max = max;
158 +static DEVICE_ATTR(fade, 0644, led_fade_show, led_fade_store);
160 +static ssize_t led_duty_cycle_show(struct device *dev,
161 + struct device_attribute *attr, char *buf)
163 + struct led_classdev *led_cdev = dev_get_drvdata(dev);
164 + struct rt_timer *rt = container_of(led_cdev->trigger, struct rt_timer, led_trigger);
166 + return sprintf(buf, "%u\n", rt->duty_cycle);
169 +static ssize_t led_duty_cycle_store(struct device *dev,
170 + struct device_attribute *attr, const char *buf, size_t size)
172 + struct led_classdev *led_cdev = dev_get_drvdata(dev);
173 + struct rt_timer *rt = container_of(led_cdev->trigger, struct rt_timer, led_trigger);
174 + unsigned long state;
175 + ssize_t ret = -EINVAL;
177 + ret = kstrtoul(buf, 10, &state);
182 + rt->duty_cycle = state;
184 + rt->duty_cycle = 100;
191 +static DEVICE_ATTR(duty_cycle, 0644, led_duty_cycle_show, led_duty_cycle_store);
193 +static void rt_timer_trig_activate(struct led_classdev *led_cdev)
195 + struct rt_timer *rt = container_of(led_cdev->trigger, struct rt_timer, led_trigger);
196 + struct rt_timer_gpio *gpio_data;
199 + led_cdev->trigger_data = NULL;
200 + gpio_data = kzalloc(sizeof(*gpio_data), GFP_KERNEL);
204 + rc = device_create_file(led_cdev->dev, &dev_attr_duty_cycle);
207 + rc = device_create_file(led_cdev->dev, &dev_attr_fade);
209 + goto err_out_duty_cycle;
211 + led_cdev->activated = true;
212 + led_cdev->trigger_data = gpio_data;
213 + gpio_data->led = led_cdev;
214 + list_add(&gpio_data->list, &rt->gpios);
215 + led_cdev->trigger_data = gpio_data;
216 + rt_timer_enable(rt);
220 + device_remove_file(led_cdev->dev, &dev_attr_duty_cycle);
226 +static void rt_timer_trig_deactivate(struct led_classdev *led_cdev)
228 + struct rt_timer *rt = container_of(led_cdev->trigger, struct rt_timer, led_trigger);
229 + struct rt_timer_gpio *gpio_data = (struct rt_timer_gpio*) led_cdev->trigger_data;
231 + if (led_cdev->activated) {
232 + device_remove_file(led_cdev->dev, &dev_attr_duty_cycle);
233 + device_remove_file(led_cdev->dev, &dev_attr_fade);
234 + led_cdev->activated = false;
237 + list_del(&gpio_data->list);
238 + rt_timer_disable(rt);
239 + led_set_brightness(led_cdev, LED_OFF);
242 static int rt_timer_probe(struct platform_device *pdev)
244 struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
245 + const __be32 *divisor;
250 rt = devm_kzalloc(&pdev->dev, sizeof(*rt), GFP_KERNEL);
252 @@ -140,12 +304,29 @@ static int rt_timer_probe(struct platfor
256 + rt->duty_cycle = 100;
257 rt->dev = &pdev->dev;
258 platform_set_drvdata(pdev, rt);
260 - rt_timer_request(rt);
261 - rt_timer_config(rt, 2);
262 - rt_timer_enable(rt);
263 + ret = rt_timer_request(rt);
267 + divisor = of_get_property(pdev->dev.of_node, "ralink,divisor", NULL);
269 + rt_timer_config(rt, be32_to_cpu(*divisor));
271 + rt_timer_config(rt, 200);
273 + rt->led_trigger.name = "pwmtimer",
274 + rt->led_trigger.activate = rt_timer_trig_activate,
275 + rt->led_trigger.deactivate = rt_timer_trig_deactivate,
277 + ret = led_trigger_register(&rt->led_trigger);
281 + INIT_LIST_HEAD(&rt->gpios);
283 dev_info(&pdev->dev, "maximum frequency is %luHz\n", rt->timer_freq);
285 @@ -156,6 +337,7 @@ static int rt_timer_remove(struct platfo
287 struct rt_timer *rt = platform_get_drvdata(pdev);
289 + led_trigger_unregister(&rt->led_trigger);
290 rt_timer_disable(rt);
293 @@ -180,6 +362,6 @@ static struct platform_driver rt_timer_d
295 module_platform_driver(rt_timer_driver);
297 -MODULE_DESCRIPTION("Ralink RT2880 timer");
298 +MODULE_DESCRIPTION("Ralink RT2880 timer / pseudo pwm");
299 MODULE_AUTHOR("John Crispin <blogic@openwrt.org");
300 MODULE_LICENSE("GPL");