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,