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authorLinus Torvalds <torvalds@linux-foundation.org>2012-12-19 17:19:07 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2012-12-19 17:19:07 +0100
commit74779e22261172ea728b989310f6ecc991b57d62 (patch)
treea6c71e02bf6cefc9e0d261dd1ab11f4a7433ed92 /drivers/pwm/pwm-vt8500.c
parentMerge tag 'for-v3.8-part2' of git://git.infradead.org/battery-2.6 (diff)
parentpwm: samsung: add missing s3c->pwm_id assignment (diff)
downloadlinux-74779e22261172ea728b989310f6ecc991b57d62.tar.xz
linux-74779e22261172ea728b989310f6ecc991b57d62.zip
Merge tag 'for-3.8-rc1' of git://gitorious.org/linux-pwm/linux-pwm
Pull pwm changes from Thierry Reding: "A new driver has been added for the SPEAr platform and the TWL4030/6030 driver has been replaced by two drivers that control the regular PWMs and the PWM driven LEDs provided by the chips. The vt8500, tiecap, tiehrpwm, i.MX, LPC32xx and Samsung drivers have all been improved and the device tree bindings now support the PWM signal polarity." Fix up trivial conflicts due to __devinit/exit removal. * tag 'for-3.8-rc1' of git://gitorious.org/linux-pwm/linux-pwm: (21 commits) pwm: samsung: add missing s3c->pwm_id assignment pwm: lpc32xx: Set the chip base for dynamic allocation pwm: lpc32xx: Properly disable the clock on device removal pwm: lpc32xx: Fix the PWM polarity pwm: i.MX: eliminate build warning pwm: Export of_pwm_xlate_with_flags() pwm: Remove pwm-twl6030 driver pwm: New driver to support PWM driven LEDs on TWL4030/6030 series of PMICs pwm: New driver to support PWMs on TWL4030/6030 series of PMICs pwm: pwm-tiehrpwm: pinctrl support pwm: tiehrpwm: Add device-tree binding pwm: pwm-tiehrpwm: Adding TBCLK gating support. pwm: pwm-tiecap: pinctrl support pwm: tiecap: Add device-tree binding pwm: Add TI PWM subsystem driver pwm: Device tree support for PWM polarity pwm: vt8500: Ensure PWM clock is enabled during pwm_config pwm: vt8500: Fix build error pwm: spear: Staticize spear_pwm_config() pwm: Add SPEAr PWM chip driver support ...
Diffstat (limited to 'drivers/pwm/pwm-vt8500.c')
-rw-r--r--drivers/pwm/pwm-vt8500.c98
1 files changed, 74 insertions, 24 deletions
diff --git a/drivers/pwm/pwm-vt8500.c b/drivers/pwm/pwm-vt8500.c
index ad14389b7144..b0ba2d403439 100644
--- a/drivers/pwm/pwm-vt8500.c
+++ b/drivers/pwm/pwm-vt8500.c
@@ -1,7 +1,8 @@
/*
* drivers/pwm/pwm-vt8500.c
*
- * Copyright (C) 2010 Alexey Charkov <alchark@gmail.com>
+ * Copyright (C) 2012 Tony Prisk <linux@prisktech.co.nz>
+ * Copyright (C) 2010 Alexey Charkov <alchark@gmail.com>
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
@@ -21,14 +22,24 @@
#include <linux/io.h>
#include <linux/pwm.h>
#include <linux/delay.h>
+#include <linux/clk.h>
#include <asm/div64.h>
-#define VT8500_NR_PWMS 4
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_address.h>
+
+/*
+ * SoC architecture allocates register space for 4 PWMs but only
+ * 2 are currently implemented.
+ */
+#define VT8500_NR_PWMS 2
struct vt8500_chip {
struct pwm_chip chip;
void __iomem *base;
+ struct clk *clk;
};
#define to_vt8500_chip(chip) container_of(chip, struct vt8500_chip, chip)
@@ -51,8 +62,15 @@ static int vt8500_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
struct vt8500_chip *vt8500 = to_vt8500_chip(chip);
unsigned long long c;
unsigned long period_cycles, prescale, pv, dc;
+ int err;
- c = 25000000/2; /* wild guess --- need to implement clocks */
+ err = clk_enable(vt8500->clk);
+ if (err < 0) {
+ dev_err(chip->dev, "failed to enable clock\n");
+ return err;
+ }
+
+ c = clk_get_rate(vt8500->clk);
c = c * period_ns;
do_div(c, 1000000000);
period_cycles = c;
@@ -64,8 +82,10 @@ static int vt8500_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
if (pv > 4095)
pv = 4095;
- if (prescale > 1023)
+ if (prescale > 1023) {
+ clk_disable(vt8500->clk);
return -EINVAL;
+ }
c = (unsigned long long)pv * duty_ns;
do_div(c, period_ns);
@@ -80,13 +100,21 @@ static int vt8500_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
pwm_busy_wait(vt8500->base + 0x40 + pwm->hwpwm, (1 << 3));
writel(dc, vt8500->base + 0xc + (pwm->hwpwm << 4));
+ clk_disable(vt8500->clk);
return 0;
}
static int vt8500_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
{
+ int err;
struct vt8500_chip *vt8500 = to_vt8500_chip(chip);
+ err = clk_enable(vt8500->clk);
+ if (err < 0) {
+ dev_err(chip->dev, "failed to enable clock\n");
+ return err;
+ }
+
pwm_busy_wait(vt8500->base + 0x40 + pwm->hwpwm, (1 << 0));
writel(5, vt8500->base + (pwm->hwpwm << 4));
return 0;
@@ -98,6 +126,8 @@ static void vt8500_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
pwm_busy_wait(vt8500->base + 0x40 + pwm->hwpwm, (1 << 0));
writel(0, vt8500->base + (pwm->hwpwm << 4));
+
+ clk_disable(vt8500->clk);
}
static struct pwm_ops vt8500_pwm_ops = {
@@ -107,12 +137,24 @@ static struct pwm_ops vt8500_pwm_ops = {
.owner = THIS_MODULE,
};
-static int __devinit pwm_probe(struct platform_device *pdev)
+static const struct of_device_id vt8500_pwm_dt_ids[] = {
+ { .compatible = "via,vt8500-pwm", },
+ { /* Sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, vt8500_pwm_dt_ids);
+
+static int vt8500_pwm_probe(struct platform_device *pdev)
{
struct vt8500_chip *chip;
struct resource *r;
+ struct device_node *np = pdev->dev.of_node;
int ret;
+ if (!np) {
+ dev_err(&pdev->dev, "invalid devicetree node\n");
+ return -EINVAL;
+ }
+
chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL);
if (chip == NULL) {
dev_err(&pdev->dev, "failed to allocate memory\n");
@@ -124,6 +166,12 @@ static int __devinit pwm_probe(struct platform_device *pdev)
chip->chip.base = -1;
chip->chip.npwm = VT8500_NR_PWMS;
+ chip->clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(chip->clk)) {
+ dev_err(&pdev->dev, "clock source not specified\n");
+ return PTR_ERR(chip->clk);
+ }
+
r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (r == NULL) {
dev_err(&pdev->dev, "no memory resource defined\n");
@@ -131,18 +179,26 @@ static int __devinit pwm_probe(struct platform_device *pdev)
}
chip->base = devm_request_and_ioremap(&pdev->dev, r);
- if (chip->base == NULL)
+ if (!chip->base)
return -EADDRNOTAVAIL;
+ ret = clk_prepare(chip->clk);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "failed to prepare clock\n");
+ return ret;
+ }
+
ret = pwmchip_add(&chip->chip);
- if (ret < 0)
+ if (ret < 0) {
+ dev_err(&pdev->dev, "failed to add PWM chip\n");
return ret;
+ }
platform_set_drvdata(pdev, chip);
return ret;
}
-static int __devexit pwm_remove(struct platform_device *pdev)
+static int vt8500_pwm_remove(struct platform_device *pdev)
{
struct vt8500_chip *chip;
@@ -150,28 +206,22 @@ static int __devexit pwm_remove(struct platform_device *pdev)
if (chip == NULL)
return -ENODEV;
+ clk_unprepare(chip->clk);
+
return pwmchip_remove(&chip->chip);
}
-static struct platform_driver pwm_driver = {
+static struct platform_driver vt8500_pwm_driver = {
+ .probe = vt8500_pwm_probe,
+ .remove = vt8500_pwm_remove,
.driver = {
.name = "vt8500-pwm",
.owner = THIS_MODULE,
+ .of_match_table = vt8500_pwm_dt_ids,
},
- .probe = pwm_probe,
- .remove = __devexit_p(pwm_remove),
};
+module_platform_driver(vt8500_pwm_driver);
-static int __init pwm_init(void)
-{
- return platform_driver_register(&pwm_driver);
-}
-arch_initcall(pwm_init);
-
-static void __exit pwm_exit(void)
-{
- platform_driver_unregister(&pwm_driver);
-}
-module_exit(pwm_exit);
-
-MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("VT8500 PWM Driver");
+MODULE_AUTHOR("Tony Prisk <linux@prisktech.co.nz>");
+MODULE_LICENSE("GPL v2");