diff options
Diffstat (limited to 'drivers/pwm/pwm-imx.c')
| -rw-r--r-- | drivers/pwm/pwm-imx.c | 308 |
1 files changed, 0 insertions, 308 deletions
diff --git a/drivers/pwm/pwm-imx.c b/drivers/pwm/pwm-imx.c deleted file mode 100644 index 2b7c4f88b461..000000000000 --- a/drivers/pwm/pwm-imx.c +++ /dev/null @@ -1,308 +0,0 @@ -/* - * simple driver for PWM (Pulse Width Modulator) controller - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 as - * published by the Free Software Foundation. - * - * Derived from pxa PWM driver by eric miao <eric.miao@marvell.com> - */ - -#include <linux/module.h> -#include <linux/kernel.h> -#include <linux/platform_device.h> -#include <linux/slab.h> -#include <linux/err.h> -#include <linux/clk.h> -#include <linux/io.h> -#include <linux/pwm.h> -#include <linux/of_device.h> - -/* i.MX1 and i.MX21 share the same PWM function block: */ - -#define MX1_PWMC 0x00 /* PWM Control Register */ -#define MX1_PWMS 0x04 /* PWM Sample Register */ -#define MX1_PWMP 0x08 /* PWM Period Register */ - -#define MX1_PWMC_EN (1 << 4) - -/* i.MX27, i.MX31, i.MX35 share the same PWM function block: */ - -#define MX3_PWMCR 0x00 /* PWM Control Register */ -#define MX3_PWMSAR 0x0C /* PWM Sample Register */ -#define MX3_PWMPR 0x10 /* PWM Period Register */ -#define MX3_PWMCR_PRESCALER(x) (((x - 1) & 0xFFF) << 4) -#define MX3_PWMCR_DOZEEN (1 << 24) -#define MX3_PWMCR_WAITEN (1 << 23) -#define MX3_PWMCR_DBGEN (1 << 22) -#define MX3_PWMCR_CLKSRC_IPG_HIGH (2 << 16) -#define MX3_PWMCR_CLKSRC_IPG (1 << 16) -#define MX3_PWMCR_EN (1 << 0) - -struct imx_chip { - struct clk *clk_per; - struct clk *clk_ipg; - - void __iomem *mmio_base; - - struct pwm_chip chip; - - int (*config)(struct pwm_chip *chip, - struct pwm_device *pwm, int duty_ns, int period_ns); - void (*set_enable)(struct pwm_chip *chip, bool enable); -}; - -#define to_imx_chip(chip) container_of(chip, struct imx_chip, chip) - -static int imx_pwm_config_v1(struct pwm_chip *chip, - struct pwm_device *pwm, int duty_ns, int period_ns) -{ - struct imx_chip *imx = to_imx_chip(chip); - - /* - * The PWM subsystem allows for exact frequencies. However, - * I cannot connect a scope on my device to the PWM line and - * thus cannot provide the program the PWM controller - * exactly. Instead, I'm relying on the fact that the - * Bootloader (u-boot or WinCE+haret) has programmed the PWM - * function group already. So I'll just modify the PWM sample - * register to follow the ratio of duty_ns vs. period_ns - * accordingly. - * - * This is good enough for programming the brightness of - * the LCD backlight. - * - * The real implementation would divide PERCLK[0] first by - * both the prescaler (/1 .. /128) and then by CLKSEL - * (/2 .. /16). - */ - u32 max = readl(imx->mmio_base + MX1_PWMP); - u32 p = max * duty_ns / period_ns; - writel(max - p, imx->mmio_base + MX1_PWMS); - - return 0; -} - -static void imx_pwm_set_enable_v1(struct pwm_chip *chip, bool enable) -{ - struct imx_chip *imx = to_imx_chip(chip); - u32 val; - - val = readl(imx->mmio_base + MX1_PWMC); - - if (enable) - val |= MX1_PWMC_EN; - else - val &= ~MX1_PWMC_EN; - - writel(val, imx->mmio_base + MX1_PWMC); -} - -static int imx_pwm_config_v2(struct pwm_chip *chip, - struct pwm_device *pwm, int duty_ns, int period_ns) -{ - struct imx_chip *imx = to_imx_chip(chip); - unsigned long long c; - unsigned long period_cycles, duty_cycles, prescale; - u32 cr; - - c = clk_get_rate(imx->clk_per); - c = c * period_ns; - do_div(c, 1000000000); - period_cycles = c; - - prescale = period_cycles / 0x10000 + 1; - - period_cycles /= prescale; - c = (unsigned long long)period_cycles * duty_ns; - do_div(c, period_ns); - duty_cycles = c; - - /* - * according to imx pwm RM, the real period value should be - * PERIOD value in PWMPR plus 2. - */ - if (period_cycles > 2) - period_cycles -= 2; - else - period_cycles = 0; - - writel(duty_cycles, imx->mmio_base + MX3_PWMSAR); - writel(period_cycles, imx->mmio_base + MX3_PWMPR); - - cr = MX3_PWMCR_PRESCALER(prescale) | - MX3_PWMCR_DOZEEN | MX3_PWMCR_WAITEN | - MX3_PWMCR_DBGEN | MX3_PWMCR_CLKSRC_IPG_HIGH; - - if (test_bit(PWMF_ENABLED, &pwm->flags)) - cr |= MX3_PWMCR_EN; - - writel(cr, imx->mmio_base + MX3_PWMCR); - - return 0; -} - -static void imx_pwm_set_enable_v2(struct pwm_chip *chip, bool enable) -{ - struct imx_chip *imx = to_imx_chip(chip); - u32 val; - - val = readl(imx->mmio_base + MX3_PWMCR); - - if (enable) - val |= MX3_PWMCR_EN; - else - val &= ~MX3_PWMCR_EN; - - writel(val, imx->mmio_base + MX3_PWMCR); -} - -static int imx_pwm_config(struct pwm_chip *chip, - struct pwm_device *pwm, int duty_ns, int period_ns) -{ - struct imx_chip *imx = to_imx_chip(chip); - int ret; - - ret = clk_prepare_enable(imx->clk_ipg); - if (ret) - return ret; - - ret = imx->config(chip, pwm, duty_ns, period_ns); - - clk_disable_unprepare(imx->clk_ipg); - - return ret; -} - -static int imx_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) -{ - struct imx_chip *imx = to_imx_chip(chip); - int ret; - - ret = clk_prepare_enable(imx->clk_per); - if (ret) - return ret; - - imx->set_enable(chip, true); - - return 0; -} - -static void imx_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) -{ - struct imx_chip *imx = to_imx_chip(chip); - - imx->set_enable(chip, false); - - clk_disable_unprepare(imx->clk_per); -} - -static struct pwm_ops imx_pwm_ops = { - .enable = imx_pwm_enable, - .disable = imx_pwm_disable, - .config = imx_pwm_config, - .owner = THIS_MODULE, -}; - -struct imx_pwm_data { - int (*config)(struct pwm_chip *chip, - struct pwm_device *pwm, int duty_ns, int period_ns); - void (*set_enable)(struct pwm_chip *chip, bool enable); -}; - -static struct imx_pwm_data imx_pwm_data_v1 = { - .config = imx_pwm_config_v1, - .set_enable = imx_pwm_set_enable_v1, -}; - -static struct imx_pwm_data imx_pwm_data_v2 = { - .config = imx_pwm_config_v2, - .set_enable = imx_pwm_set_enable_v2, -}; - -static const struct of_device_id imx_pwm_dt_ids[] = { - { .compatible = "fsl,imx1-pwm", .data = &imx_pwm_data_v1, }, - { .compatible = "fsl,imx27-pwm", .data = &imx_pwm_data_v2, }, - { /* sentinel */ } -}; -MODULE_DEVICE_TABLE(of, imx_pwm_dt_ids); - -static int imx_pwm_probe(struct platform_device *pdev) -{ - const struct of_device_id *of_id = - of_match_device(imx_pwm_dt_ids, &pdev->dev); - const struct imx_pwm_data *data; - struct imx_chip *imx; - struct resource *r; - int ret = 0; - - if (!of_id) - return -ENODEV; - - imx = devm_kzalloc(&pdev->dev, sizeof(*imx), GFP_KERNEL); - if (imx == NULL) { - dev_err(&pdev->dev, "failed to allocate memory\n"); - return -ENOMEM; - } - - imx->clk_per = devm_clk_get(&pdev->dev, "per"); - if (IS_ERR(imx->clk_per)) { - dev_err(&pdev->dev, "getting per clock failed with %ld\n", - PTR_ERR(imx->clk_per)); - return PTR_ERR(imx->clk_per); - } - - imx->clk_ipg = devm_clk_get(&pdev->dev, "ipg"); - if (IS_ERR(imx->clk_ipg)) { - dev_err(&pdev->dev, "getting ipg clock failed with %ld\n", - PTR_ERR(imx->clk_ipg)); - return PTR_ERR(imx->clk_ipg); - } - - imx->chip.ops = &imx_pwm_ops; - imx->chip.dev = &pdev->dev; - imx->chip.base = -1; - imx->chip.npwm = 1; - - r = platform_get_resource(pdev, IORESOURCE_MEM, 0); - imx->mmio_base = devm_ioremap_resource(&pdev->dev, r); - if (IS_ERR(imx->mmio_base)) - return PTR_ERR(imx->mmio_base); - - data = of_id->data; - imx->config = data->config; - imx->set_enable = data->set_enable; - - ret = pwmchip_add(&imx->chip); - if (ret < 0) - return ret; - - platform_set_drvdata(pdev, imx); - return 0; -} - -static int imx_pwm_remove(struct platform_device *pdev) -{ - struct imx_chip *imx; - - imx = platform_get_drvdata(pdev); - if (imx == NULL) - return -ENODEV; - - return pwmchip_remove(&imx->chip); -} - -static struct platform_driver imx_pwm_driver = { - .driver = { - .name = "imx-pwm", - .owner = THIS_MODULE, - .of_match_table = of_match_ptr(imx_pwm_dt_ids), - }, - .probe = imx_pwm_probe, - .remove = imx_pwm_remove, -}; - -module_platform_driver(imx_pwm_driver); - -MODULE_LICENSE("GPL v2"); -MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>"); |