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authorMike Dunn <mikedunn@newsguy.com>2013-09-21 23:19:33 +0400
committerThierry Reding <thierry.reding@gmail.com>2013-12-04 13:18:52 +0400
commitb52fa7bc5dc9697fb5983727d276dd565d85a8d0 (patch)
tree834180da5e34ac663df68a57a64e5608fc004e6b /drivers/pwm
parent6ce4eac1f600b34f2f7f58f9cd8f0503d79e42ae (diff)
downloadlinux-b52fa7bc5dc9697fb5983727d276dd565d85a8d0.tar.xz
pwm: pxa: Add device tree support
This patch adds device tree support to the PXA's PWM driver. Nothing needs to be extracted from the device tree node by the PWM device. Client devices need only specify the period; the per-chip index is implicitly zero because one device node must be present for each PWM output in use. This approach is more convenient due to the wide variability in the number of PWM channels present across the various PXA variants, and is made possible by the fact that the register sets for each PWM channel are segregated from each other. An of_xlate() method is added to parse this single-cell node. The existing ID table is reused for the match table data. Tested on a Palm Treo 680 (both platform data and DT cases). Signed-off-by: Mike Dunn <mikedunn@newsguy.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Diffstat (limited to 'drivers/pwm')
-rw-r--r--drivers/pwm/pwm-pxa.c53
1 files changed, 53 insertions, 0 deletions
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,