From: Sascha Hauer Date: Thu, 15 Mar 2012 09:04:37 +0000 (+0100) Subject: ARM vt8500: Move vt8500 pwm driver to pwm framework X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=a245ccebb4aad9fae60597d5cbad158c0de4483e;hp=215c29d3d0e925189ade522d1ea6052a320d7692;p=deliverable%2Flinux.git ARM vt8500: Move vt8500 pwm driver to pwm framework Move the driver to drivers/pwm/ and convert it to use the framework. Signed-off-by: Sascha Hauer Cc: Alexey Charkov Signed-off-by: Thierry Reding --- diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 84449dd8f031..8da8f82f6fe3 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -962,7 +962,6 @@ config ARCH_VT8500 select ARCH_HAS_CPUFREQ select GENERIC_CLOCKEVENTS select ARCH_REQUIRE_GPIOLIB - select HAVE_PWM help Support for VIA/WonderMedia VT8500/WM85xx System-on-Chip. diff --git a/arch/arm/mach-vt8500/Makefile b/arch/arm/mach-vt8500/Makefile index 81aedb7c893c..8df9e4abab6d 100644 --- a/arch/arm/mach-vt8500/Makefile +++ b/arch/arm/mach-vt8500/Makefile @@ -5,5 +5,3 @@ obj-$(CONFIG_VTWM_VERSION_WM8505) += devices-wm8505.o obj-$(CONFIG_MACH_BV07) += bv07.o obj-$(CONFIG_MACH_WM8505_7IN_NETBOOK) += wm8505_7in.o - -obj-$(CONFIG_HAVE_PWM) += pwm.o diff --git a/arch/arm/mach-vt8500/pwm.c b/arch/arm/mach-vt8500/pwm.c deleted file mode 100644 index 8ad825e93592..000000000000 --- a/arch/arm/mach-vt8500/pwm.c +++ /dev/null @@ -1,265 +0,0 @@ -/* - * arch/arm/mach-vt8500/pwm.c - * - * Copyright (C) 2010 Alexey Charkov - * - * This software is licensed under the terms of the GNU General Public - * License version 2, as published by the Free Software Foundation, and - * may be copied, distributed, and modified under those terms. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - */ - -#include -#include -#include -#include -#include -#include -#include -#include - -#include - -#define VT8500_NR_PWMS 4 - -static DEFINE_MUTEX(pwm_lock); -static LIST_HEAD(pwm_list); - -struct pwm_device { - struct list_head node; - struct platform_device *pdev; - - const char *label; - - void __iomem *regbase; - - unsigned int use_count; - unsigned int pwm_id; -}; - -#define msecs_to_loops(t) (loops_per_jiffy / 1000 * HZ * t) -static inline void pwm_busy_wait(void __iomem *reg, u8 bitmask) -{ - int loops = msecs_to_loops(10); - while ((readb(reg) & bitmask) && --loops) - cpu_relax(); - - if (unlikely(!loops)) - pr_warning("Waiting for status bits 0x%x to clear timed out\n", - bitmask); -} - -int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns) -{ - unsigned long long c; - unsigned long period_cycles, prescale, pv, dc; - - if (pwm == NULL || period_ns == 0 || duty_ns > period_ns) - return -EINVAL; - - c = 25000000/2; /* wild guess --- need to implement clocks */ - c = c * period_ns; - do_div(c, 1000000000); - period_cycles = c; - - if (period_cycles < 1) - period_cycles = 1; - prescale = (period_cycles - 1) / 4096; - pv = period_cycles / (prescale + 1) - 1; - if (pv > 4095) - pv = 4095; - - if (prescale > 1023) - return -EINVAL; - - c = (unsigned long long)pv * duty_ns; - do_div(c, period_ns); - dc = c; - - pwm_busy_wait(pwm->regbase + 0x40 + pwm->pwm_id, (1 << 1)); - writel(prescale, pwm->regbase + 0x4 + (pwm->pwm_id << 4)); - - pwm_busy_wait(pwm->regbase + 0x40 + pwm->pwm_id, (1 << 2)); - writel(pv, pwm->regbase + 0x8 + (pwm->pwm_id << 4)); - - pwm_busy_wait(pwm->regbase + 0x40 + pwm->pwm_id, (1 << 3)); - writel(dc, pwm->regbase + 0xc + (pwm->pwm_id << 4)); - - return 0; -} -EXPORT_SYMBOL(pwm_config); - -int pwm_enable(struct pwm_device *pwm) -{ - pwm_busy_wait(pwm->regbase + 0x40 + pwm->pwm_id, (1 << 0)); - writel(5, pwm->regbase + (pwm->pwm_id << 4)); - return 0; -} -EXPORT_SYMBOL(pwm_enable); - -void pwm_disable(struct pwm_device *pwm) -{ - pwm_busy_wait(pwm->regbase + 0x40 + pwm->pwm_id, (1 << 0)); - writel(0, pwm->regbase + (pwm->pwm_id << 4)); -} -EXPORT_SYMBOL(pwm_disable); - -struct pwm_device *pwm_request(int pwm_id, const char *label) -{ - struct pwm_device *pwm; - int found = 0; - - mutex_lock(&pwm_lock); - - list_for_each_entry(pwm, &pwm_list, node) { - if (pwm->pwm_id == pwm_id) { - found = 1; - break; - } - } - - if (found) { - if (pwm->use_count == 0) { - pwm->use_count++; - pwm->label = label; - } else { - pwm = ERR_PTR(-EBUSY); - } - } else { - pwm = ERR_PTR(-ENOENT); - } - - mutex_unlock(&pwm_lock); - return pwm; -} -EXPORT_SYMBOL(pwm_request); - -void pwm_free(struct pwm_device *pwm) -{ - mutex_lock(&pwm_lock); - - if (pwm->use_count) { - pwm->use_count--; - pwm->label = NULL; - } else { - pr_warning("PWM device already freed\n"); - } - - mutex_unlock(&pwm_lock); -} -EXPORT_SYMBOL(pwm_free); - -static inline void __add_pwm(struct pwm_device *pwm) -{ - mutex_lock(&pwm_lock); - list_add_tail(&pwm->node, &pwm_list); - mutex_unlock(&pwm_lock); -} - -static int __devinit pwm_probe(struct platform_device *pdev) -{ - struct pwm_device *pwms; - struct resource *r; - int ret = 0; - int i; - - pwms = kzalloc(sizeof(struct pwm_device) * VT8500_NR_PWMS, GFP_KERNEL); - if (pwms == NULL) { - dev_err(&pdev->dev, "failed to allocate memory\n"); - return -ENOMEM; - } - - for (i = 0; i < VT8500_NR_PWMS; i++) { - pwms[i].use_count = 0; - pwms[i].pwm_id = i; - pwms[i].pdev = pdev; - } - - r = platform_get_resource(pdev, IORESOURCE_MEM, 0); - if (r == NULL) { - dev_err(&pdev->dev, "no memory resource defined\n"); - ret = -ENODEV; - goto err_free; - } - - r = request_mem_region(r->start, resource_size(r), pdev->name); - if (r == NULL) { - dev_err(&pdev->dev, "failed to request memory resource\n"); - ret = -EBUSY; - goto err_free; - } - - pwms[0].regbase = ioremap(r->start, resource_size(r)); - if (pwms[0].regbase == NULL) { - dev_err(&pdev->dev, "failed to ioremap() registers\n"); - ret = -ENODEV; - goto err_free_mem; - } - - for (i = 1; i < VT8500_NR_PWMS; i++) - pwms[i].regbase = pwms[0].regbase; - - for (i = 0; i < VT8500_NR_PWMS; i++) - __add_pwm(&pwms[i]); - - platform_set_drvdata(pdev, pwms); - return 0; - -err_free_mem: - release_mem_region(r->start, resource_size(r)); -err_free: - kfree(pwms); - return ret; -} - -static int __devexit pwm_remove(struct platform_device *pdev) -{ - struct pwm_device *pwms; - struct resource *r; - int i; - - pwms = platform_get_drvdata(pdev); - if (pwms == NULL) - return -ENODEV; - - mutex_lock(&pwm_lock); - - for (i = 0; i < VT8500_NR_PWMS; i++) - list_del(&pwms[i].node); - mutex_unlock(&pwm_lock); - - iounmap(pwms[0].regbase); - - r = platform_get_resource(pdev, IORESOURCE_MEM, 0); - release_mem_region(r->start, resource_size(r)); - - kfree(pwms); - return 0; -} - -static struct platform_driver pwm_driver = { - .driver = { - .name = "vt8500-pwm", - .owner = THIS_MODULE, - }, - .probe = pwm_probe, - .remove = __devexit_p(pwm_remove), -}; - -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"); diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig index 0d9aa92636c3..a93feffbc36a 100644 --- a/drivers/pwm/Kconfig +++ b/drivers/pwm/Kconfig @@ -55,4 +55,13 @@ config PWM_TEGRA To compile this driver as a module, choose M here: the module will be called pwm-tegra. +config PWM_VT8500 + tristate "vt8500 pwm support" + depends on ARCH_VT8500 + help + Generic PWM framework driver for vt8500. + + To compile this driver as a module, choose M here: the module + will be called pwm-vt8500. + endif diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile index a1d87b173312..b7c0fcf4de16 100644 --- a/drivers/pwm/Makefile +++ b/drivers/pwm/Makefile @@ -4,3 +4,4 @@ obj-$(CONFIG_PWM_IMX) += pwm-imx.o obj-$(CONFIG_PWM_PXA) += pwm-pxa.o obj-$(CONFIG_PWM_SAMSUNG) += pwm-samsung.o obj-$(CONFIG_PWM_TEGRA) += pwm-tegra.o +obj-$(CONFIG_PWM_VT8500) += pwm-vt8500.o diff --git a/drivers/pwm/pwm-vt8500.c b/drivers/pwm/pwm-vt8500.c new file mode 100644 index 000000000000..3db0746f7200 --- /dev/null +++ b/drivers/pwm/pwm-vt8500.c @@ -0,0 +1,208 @@ +/* + * arch/arm/mach-vt8500/pwm.c + * + * Copyright (C) 2010 Alexey Charkov + * + * This software is licensed under the terms of the GNU General Public + * License version 2, as published by the Free Software Foundation, and + * may be copied, distributed, and modified under those terms. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +#define VT8500_NR_PWMS 4 + +struct vt8500_chip { + struct pwm_chip chip; + void __iomem *base; +}; + +#define to_vt8500_chip(chip) container_of(chip, struct vt8500_chip, chip) + +#define msecs_to_loops(t) (loops_per_jiffy / 1000 * HZ * t) +static inline void pwm_busy_wait(void __iomem *reg, u8 bitmask) +{ + int loops = msecs_to_loops(10); + while ((readb(reg) & bitmask) && --loops) + cpu_relax(); + + if (unlikely(!loops)) + pr_warning("Waiting for status bits 0x%x to clear timed out\n", + bitmask); +} + +static int vt8500_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, + int duty_ns, int period_ns) +{ + struct vt8500_chip *vt8500 = to_vt8500_chip(chip); + unsigned long long c; + unsigned long period_cycles, prescale, pv, dc; + + c = 25000000/2; /* wild guess --- need to implement clocks */ + c = c * period_ns; + do_div(c, 1000000000); + period_cycles = c; + + if (period_cycles < 1) + period_cycles = 1; + prescale = (period_cycles - 1) / 4096; + pv = period_cycles / (prescale + 1) - 1; + if (pv > 4095) + pv = 4095; + + if (prescale > 1023) + return -EINVAL; + + c = (unsigned long long)pv * duty_ns; + do_div(c, period_ns); + dc = c; + + pwm_busy_wait(vt8500->base + 0x40 + pwm->hwpwm, (1 << 1)); + writel(prescale, vt8500->base + 0x4 + (pwm->hwpwm << 4)); + + pwm_busy_wait(vt8500->base + 0x40 + pwm->hwpwm, (1 << 2)); + writel(pv, vt8500->base + 0x8 + (pwm->hwpwm << 4)); + + pwm_busy_wait(vt8500->base + 0x40 + pwm->hwpwm, (1 << 3)); + writel(dc, vt8500->base + 0xc + (pwm->hwpwm << 4)); + + return 0; +} + +static int vt8500_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct vt8500_chip *vt8500 = to_vt8500_chip(chip); + + pwm_busy_wait(vt8500->base + 0x40 + pwm->hwpwm, (1 << 0)); + writel(5, vt8500->base + (pwm->hwpwm << 4)); + return 0; +} + +static void vt8500_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct vt8500_chip *vt8500 = to_vt8500_chip(chip); + + pwm_busy_wait(vt8500->base + 0x40 + pwm->hwpwm, (1 << 0)); + writel(0, vt8500->base + (pwm->hwpwm << 4)); +} + +static struct pwm_ops vt8500_pwm_ops = { + .enable = vt8500_pwm_enable, + .disable = vt8500_pwm_disable, + .config = vt8500_pwm_config, + .owner = THIS_MODULE, +}; + +static int __devinit pwm_probe(struct platform_device *pdev) +{ + struct vt8500_chip *chip; + struct resource *r; + int ret; + + chip = kzalloc(sizeof(*chip), GFP_KERNEL); + if (chip == NULL) { + dev_err(&pdev->dev, "failed to allocate memory\n"); + return -ENOMEM; + } + + chip->chip.dev = &pdev->dev; + chip->chip.ops = &vt8500_pwm_ops; + chip->chip.base = -1; + chip->chip.npwm = VT8500_NR_PWMS; + + r = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (r == NULL) { + dev_err(&pdev->dev, "no memory resource defined\n"); + ret = -ENODEV; + goto err_free; + } + + r = request_mem_region(r->start, resource_size(r), pdev->name); + if (r == NULL) { + dev_err(&pdev->dev, "failed to request memory resource\n"); + ret = -EBUSY; + goto err_free; + } + + chip->base = ioremap(r->start, resource_size(r)); + if (chip->base == NULL) { + dev_err(&pdev->dev, "failed to ioremap() registers\n"); + ret = -ENODEV; + goto err_free_mem; + } + + ret = pwmchip_add(&chip->chip); + if (ret < 0) + goto err_unmap; + + platform_set_drvdata(pdev, chip); + return ret; + +err_unmap: + iounmap(chip->base); +err_free_mem: + release_mem_region(r->start, resource_size(r)); +err_free: + kfree(chip); + return ret; +} + +static int __devexit pwm_remove(struct platform_device *pdev) +{ + struct vt8500_chip *chip; + struct resource *r; + int err; + + chip = platform_get_drvdata(pdev); + if (chip == NULL) + return -ENODEV; + + err = pwmchip_remove(&chip->chip); + if (err < 0) + return err; + + iounmap(chip->base); + + r = platform_get_resource(pdev, IORESOURCE_MEM, 0); + release_mem_region(r->start, resource_size(r)); + + kfree(chip); + return 0; +} + +static struct platform_driver pwm_driver = { + .driver = { + .name = "vt8500-pwm", + .owner = THIS_MODULE, + }, + .probe = pwm_probe, + .remove = __devexit_p(pwm_remove), +}; + +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");