diff options
| -rw-r--r-- | Documentation/devicetree/bindings/pwm/vt8500-pwm.txt | 17 | ||||
| -rw-r--r-- | drivers/pwm/pwm-vt8500.c | 86 |
2 files changed, 80 insertions, 23 deletions
diff --git a/Documentation/devicetree/bindings/pwm/vt8500-pwm.txt b/Documentation/devicetree/bindings/pwm/vt8500-pwm.txt new file mode 100644 index 000000000000..bcc63678a9a5 --- /dev/null +++ b/Documentation/devicetree/bindings/pwm/vt8500-pwm.txt @@ -0,0 +1,17 @@ +VIA/Wondermedia VT8500/WM8xxx series SoC PWM controller + +Required properties: +- compatible: should be "via,vt8500-pwm" +- reg: physical base address and length of the controller's registers +- #pwm-cells: should be 2. The first cell specifies the per-chip index + of the PWM to use and the second cell is the period in nanoseconds. +- clocks: phandle to the PWM source clock + +Example: + +pwm1: pwm@d8220000 { + #pwm-cells = <2>; + compatible = "via,vt8500-pwm"; + reg = <0xd8220000 0x1000>; + clocks = <&clkpwm>; +}; diff --git a/drivers/pwm/pwm-vt8500.c b/drivers/pwm/pwm-vt8500.c index ad14389b7144..970b0c6e268f 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) @@ -52,7 +63,7 @@ static int vt8500_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, unsigned long long c; unsigned long period_cycles, prescale, pv, dc; - c = 25000000/2; /* wild guess --- need to implement clocks */ + c = clk_get_rate(vt8500->clk); c = c * period_ns; do_div(c, 1000000000); period_cycles = c; @@ -85,8 +96,15 @@ static int vt8500_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, 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 +116,8 @@ 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 +127,24 @@ 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 +156,12 @@ 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 +169,26 @@ 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 +196,22 @@ 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"); |