diff options
Diffstat (limited to 'drivers/pwm/pwm-bfin.c')
| -rw-r--r-- | drivers/pwm/pwm-bfin.c | 164 |
1 files changed, 164 insertions, 0 deletions
diff --git a/drivers/pwm/pwm-bfin.c b/drivers/pwm/pwm-bfin.c new file mode 100644 index 000000000000..a0c6bf9070ea --- /dev/null +++ b/drivers/pwm/pwm-bfin.c @@ -0,0 +1,164 @@ +/* + * Blackfin Pulse Width Modulation (PWM) core + * + * Copyright (c) 2011 Analog Devices Inc. + * + * Licensed under the GPL-2 or later. + */ + +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/pwm.h> +#include <linux/slab.h> + +#include <asm/gptimers.h> +#include <asm/portmux.h> + +struct bfin_pwm_chip { + struct pwm_chip chip; +}; + +struct bfin_pwm { + unsigned short pin; +}; + +static const unsigned short pwm_to_gptimer_per[] = { + P_TMR0, P_TMR1, P_TMR2, P_TMR3, P_TMR4, P_TMR5, + P_TMR6, P_TMR7, P_TMR8, P_TMR9, P_TMR10, P_TMR11, +}; + +static int bfin_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct bfin_pwm *priv; + int ret; + + if (pwm->hwpwm >= ARRAY_SIZE(pwm_to_gptimer_per)) + return -EINVAL; + + priv = kzalloc(sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + priv->pin = pwm_to_gptimer_per[pwm->hwpwm]; + + ret = peripheral_request(priv->pin, NULL); + if (ret) { + kfree(priv); + return ret; + } + + pwm_set_chip_data(pwm, priv); + + return 0; +} + +static void bfin_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct bfin_pwm *priv = pwm_get_chip_data(pwm); + + if (priv) { + peripheral_free(priv->pin); + kfree(priv); + } +} + +static int bfin_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, + int duty_ns, int period_ns) +{ + struct bfin_pwm *priv = pwm_get_chip_data(pwm); + unsigned long period, duty; + unsigned long long val; + + if (duty_ns < 0 || duty_ns > period_ns) + return -EINVAL; + + val = (unsigned long long)get_sclk() * period_ns; + do_div(val, NSEC_PER_SEC); + period = val; + + val = (unsigned long long)period * duty_ns; + do_div(val, period_ns); + duty = period - val; + + if (duty >= period) + duty = period - 1; + + set_gptimer_config(priv->pin, TIMER_MODE_PWM | TIMER_PERIOD_CNT); + set_gptimer_pwidth(priv->pin, duty); + set_gptimer_period(priv->pin, period); + + return 0; +} + +static int bfin_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct bfin_pwm *priv = pwm_get_chip_data(pwm); + + enable_gptimer(priv->pin); + + return 0; +} + +static void bfin_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct bfin_pwm *priv = pwm_get_chip_data(pwm); + + disable_gptimer(priv->pin); +} + +static struct pwm_ops bfin_pwm_ops = { + .request = bfin_pwm_request, + .free = bfin_pwm_free, + .config = bfin_pwm_config, + .enable = bfin_pwm_enable, + .disable = bfin_pwm_disable, + .owner = THIS_MODULE, +}; + +static int bfin_pwm_probe(struct platform_device *pdev) +{ + struct bfin_pwm_chip *pwm; + int ret; + + pwm = devm_kzalloc(&pdev->dev, sizeof(*pwm), GFP_KERNEL); + if (!pwm) { + dev_err(&pdev->dev, "failed to allocate memory\n"); + return -ENOMEM; + } + + platform_set_drvdata(pdev, pwm); + + pwm->chip.dev = &pdev->dev; + pwm->chip.ops = &bfin_pwm_ops; + pwm->chip.base = -1; + pwm->chip.npwm = 12; + + ret = pwmchip_add(&pwm->chip); + if (ret < 0) { + dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret); + return ret; + } + + return 0; +} + +static int __devexit bfin_pwm_remove(struct platform_device *pdev) +{ + struct bfin_pwm_chip *pwm = platform_get_drvdata(pdev); + + pwmchip_remove(&pwm->chip); + + return 0; +} + +static struct platform_driver bfin_pwm_driver = { + .driver = { + .name = "bfin-pwm", + }, + .probe = bfin_pwm_probe, + .remove = __devexit_p(bfin_pwm_remove), +}; + +module_platform_driver(bfin_pwm_driver); + +MODULE_LICENSE("GPL"); |