diff options
| -rw-r--r-- | Documentation/devicetree/bindings/pwm/pxa-pwm.txt | 30 | ||||
| -rw-r--r-- | drivers/pwm/pwm-pxa.c | 53 |
2 files changed, 83 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/pwm/pxa-pwm.txt b/Documentation/devicetree/bindings/pwm/pxa-pwm.txt new file mode 100644 index 000000000000..5ae9f1e3c338 --- /dev/null +++ b/Documentation/devicetree/bindings/pwm/pxa-pwm.txt @@ -0,0 +1,30 @@ +Marvell PWM controller + +Required properties: +- compatible: should be one or more of: + - "marvell,pxa250-pwm" + - "marvell,pxa270-pwm" + - "marvell,pxa168-pwm" + - "marvell,pxa910-pwm" +- reg: Physical base address and length of the registers used by the PWM channel + Note that one device instance must be created for each PWM that is used, so the + length covers only the register window for one PWM output, not that of the + entire PWM controller. Currently length is 0x10 for all supported devices. +- #pwm-cells: Should be 1. This cell is used to specify the period in + nanoseconds. + +Example PWM device node: + +pwm0: pwm@40b00000 { + compatible = "marvell,pxa250-pwm"; + reg = <0x40b00000 0x10>; + #pwm-cells = <1>; +}; + +Example PWM client node: + +backlight { + compatible = "pwm-backlight"; + pwms = <&pwm0 5000000>; + ... +} diff --git a/drivers/pwm/pwm-pxa.c b/drivers/pwm/pwm-pxa.c index a4d2164aaf55..3dc7c10bb7a0 100644 --- a/drivers/pwm/pwm-pxa.c +++ b/drivers/pwm/pwm-pxa.c @@ -19,6 +19,7 @@ #include <linux/clk.h> #include <linux/io.h> #include <linux/pwm.h> +#include <linux/of_device.h> #include <asm/div64.h> @@ -124,6 +125,46 @@ static struct pwm_ops pxa_pwm_ops = { .owner = THIS_MODULE, }; +#ifdef CONFIG_OF +/* + * Device tree users must create one device instance for each pwm channel. + * Hence we dispense with the HAS_SECONDARY_PWM and "tell" the original driver + * code that this is a single channel pxa25x-pwm. Currently all devices are + * supported identically. + */ +static struct of_device_id pwm_of_match[] = { + { .compatible = "marvell,pxa250-pwm", .data = &pwm_id_table[0]}, + { .compatible = "marvell,pxa270-pwm", .data = &pwm_id_table[0]}, + { .compatible = "marvell,pxa168-pwm", .data = &pwm_id_table[0]}, + { .compatible = "marvell,pxa910-pwm", .data = &pwm_id_table[0]}, + { } +}; +MODULE_DEVICE_TABLE(of, pwm_of_match); +#else +#define pwm_of_match NULL +#endif + +static const struct platform_device_id *pxa_pwm_get_id_dt(struct device *dev) +{ + const struct of_device_id *id = of_match_device(pwm_of_match, dev); + + return id ? id->data : NULL; +} + +static struct pwm_device * +pxa_pwm_of_xlate(struct pwm_chip *pc, const struct of_phandle_args *args) +{ + struct pwm_device *pwm; + + pwm = pwm_request_from_chip(pc, 0, NULL); + if (IS_ERR(pwm)) + return pwm; + + pwm_set_period(pwm, args->args[0]); + + return pwm; +} + static int pwm_probe(struct platform_device *pdev) { const struct platform_device_id *id = platform_get_device_id(pdev); @@ -131,6 +172,12 @@ static int pwm_probe(struct platform_device *pdev) struct resource *r; int ret = 0; + if (IS_ENABLED(CONFIG_OF) && id == NULL) + id = pxa_pwm_get_id_dt(&pdev->dev); + + if (id == NULL) + return -EINVAL; + pwm = devm_kzalloc(&pdev->dev, sizeof(*pwm), GFP_KERNEL); if (pwm == NULL) { dev_err(&pdev->dev, "failed to allocate memory\n"); @@ -146,6 +193,11 @@ static int pwm_probe(struct platform_device *pdev) pwm->chip.base = -1; pwm->chip.npwm = (id->driver_data & HAS_SECONDARY_PWM) ? 2 : 1; + if (IS_ENABLED(CONFIG_OF)) { + pwm->chip.of_xlate = pxa_pwm_of_xlate; + pwm->chip.of_pwm_n_cells = 1; + } + r = platform_get_resource(pdev, IORESOURCE_MEM, 0); pwm->mmio_base = devm_ioremap_resource(&pdev->dev, r); if (IS_ERR(pwm->mmio_base)) @@ -176,6 +228,7 @@ static struct platform_driver pwm_driver = { .driver = { .name = "pxa25x-pwm", .owner = THIS_MODULE, + .of_match_table = pwm_of_match, }, .probe = pwm_probe, .remove = pwm_remove, |