2 * Blackfin Pulse Width Modulation (PWM) core
4 * Copyright (c) 2011 Analog Devices Inc.
6 * Licensed under the GPL-2 or later.
9 #include <linux/module.h>
10 #include <linux/platform_device.h>
11 #include <linux/pwm.h>
12 #include <linux/slab.h>
14 #include <asm/gptimers.h>
15 #include <asm/portmux.h>
17 struct bfin_pwm_chip {
25 static const unsigned short pwm_to_gptimer_per[] = {
26 P_TMR0, P_TMR1, P_TMR2, P_TMR3, P_TMR4, P_TMR5,
27 P_TMR6, P_TMR7, P_TMR8, P_TMR9, P_TMR10, P_TMR11,
30 static int bfin_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
32 struct bfin_pwm *priv;
35 if (pwm->hwpwm >= ARRAY_SIZE(pwm_to_gptimer_per))
38 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
42 priv->pin = pwm_to_gptimer_per[pwm->hwpwm];
44 ret = peripheral_request(priv->pin, NULL);
50 pwm_set_chip_data(pwm, priv);
55 static void bfin_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
57 struct bfin_pwm *priv = pwm_get_chip_data(pwm);
60 peripheral_free(priv->pin);
65 static int bfin_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
66 int duty_ns, int period_ns)
68 struct bfin_pwm *priv = pwm_get_chip_data(pwm);
69 unsigned long period, duty;
70 unsigned long long val;
72 if (duty_ns < 0 || duty_ns > period_ns)
75 val = (unsigned long long)get_sclk() * period_ns;
76 do_div(val, NSEC_PER_SEC);
79 val = (unsigned long long)period * duty_ns;
80 do_div(val, period_ns);
86 set_gptimer_config(priv->pin, TIMER_MODE_PWM | TIMER_PERIOD_CNT);
87 set_gptimer_pwidth(priv->pin, duty);
88 set_gptimer_period(priv->pin, period);
93 static int bfin_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
95 struct bfin_pwm *priv = pwm_get_chip_data(pwm);
97 enable_gptimer(priv->pin);
102 static void bfin_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
104 struct bfin_pwm *priv = pwm_get_chip_data(pwm);
106 disable_gptimer(priv->pin);
109 static struct pwm_ops bfin_pwm_ops = {
110 .request = bfin_pwm_request,
111 .free = bfin_pwm_free,
112 .config = bfin_pwm_config,
113 .enable = bfin_pwm_enable,
114 .disable = bfin_pwm_disable,
115 .owner = THIS_MODULE,
118 static int bfin_pwm_probe(struct platform_device *pdev)
120 struct bfin_pwm_chip *pwm;
123 pwm = devm_kzalloc(&pdev->dev, sizeof(*pwm), GFP_KERNEL);
125 dev_err(&pdev->dev, "failed to allocate memory\n");
129 platform_set_drvdata(pdev, pwm);
131 pwm->chip.dev = &pdev->dev;
132 pwm->chip.ops = &bfin_pwm_ops;
136 ret = pwmchip_add(&pwm->chip);
138 dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
145 static int __devexit bfin_pwm_remove(struct platform_device *pdev)
147 struct bfin_pwm_chip *pwm = platform_get_drvdata(pdev);
149 return pwmchip_remove(&pwm->chip);
152 static struct platform_driver bfin_pwm_driver = {
156 .probe = bfin_pwm_probe,
157 .remove = __devexit_p(bfin_pwm_remove),
160 module_platform_driver(bfin_pwm_driver);
162 MODULE_LICENSE("GPL");