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path: root/drivers/pwm/pwm-bfin.c
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Diffstat (limited to 'drivers/pwm/pwm-bfin.c')
-rw-r--r--drivers/pwm/pwm-bfin.c164
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");