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Release 4.14 drivers/pwm/pwm-mxs.c

Directory: drivers/pwm
/*
 * Copyright 2012 Freescale Semiconductor, Inc.
 *
 * The code contained herein is licensed under the GNU General Public
 * License. You may obtain a copy of the GNU General Public License
 * Version 2 or later at the following locations:
 *
 * http://www.opensource.org/licenses/gpl-license.html
 * http://www.gnu.org/copyleft/gpl.html
 */

#include <linux/clk.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/pwm.h>
#include <linux/slab.h>
#include <linux/stmp_device.h>


#define SET	0x4

#define CLR	0x8

#define TOG	0xc


#define PWM_CTRL		0x0

#define PWM_ACTIVE0		0x10

#define PWM_PERIOD0		0x20

#define  PERIOD_PERIOD(p)	((p) & 0xffff)

#define  PERIOD_PERIOD_MAX	0x10000

#define  PERIOD_ACTIVE_HIGH	(3 << 16)

#define  PERIOD_INACTIVE_LOW	(2 << 18)

#define  PERIOD_CDIV(div)	(((div) & 0x7) << 20)

#define  PERIOD_CDIV_MAX	8


static const unsigned int cdiv[PERIOD_CDIV_MAX] = {
	1, 2, 4, 8, 16, 64, 256, 1024
};


struct mxs_pwm_chip {
	
struct pwm_chip chip;
	
struct clk *clk;
	
void __iomem *base;
};


#define to_mxs_pwm_chip(_chip) container_of(_chip, struct mxs_pwm_chip, chip)


static int mxs_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, int duty_ns, int period_ns) { struct mxs_pwm_chip *mxs = to_mxs_pwm_chip(chip); int ret, div = 0; unsigned int period_cycles, duty_cycles; unsigned long rate; unsigned long long c; rate = clk_get_rate(mxs->clk); while (1) { c = rate / cdiv[div]; c = c * period_ns; do_div(c, 1000000000); if (c < PERIOD_PERIOD_MAX) break; div++; if (div >= PERIOD_CDIV_MAX) return -EINVAL; } period_cycles = c; c *= duty_ns; do_div(c, period_ns); duty_cycles = c; /* * If the PWM channel is disabled, make sure to turn on the clock * before writing the register. Otherwise, keep it enabled. */ if (!pwm_is_enabled(pwm)) { ret = clk_prepare_enable(mxs->clk); if (ret) return ret; } writel(duty_cycles << 16, mxs->base + PWM_ACTIVE0 + pwm->hwpwm * 0x20); writel(PERIOD_PERIOD(period_cycles) | PERIOD_ACTIVE_HIGH | PERIOD_INACTIVE_LOW | PERIOD_CDIV(div), mxs->base + PWM_PERIOD0 + pwm->hwpwm * 0x20); /* * If the PWM is not enabled, turn the clock off again to save power. */ if (!pwm_is_enabled(pwm)) clk_disable_unprepare(mxs->clk); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Shawn Guo21897.32%133.33%
Gaetan Hug41.79%133.33%
Boris Brezillon20.89%133.33%
Total224100.00%3100.00%


static int mxs_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) { struct mxs_pwm_chip *mxs = to_mxs_pwm_chip(chip); int ret; ret = clk_prepare_enable(mxs->clk); if (ret) return ret; writel(1 << pwm->hwpwm, mxs->base + PWM_CTRL + SET); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Shawn Guo65100.00%1100.00%
Total65100.00%1100.00%


static void mxs_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) { struct mxs_pwm_chip *mxs = to_mxs_pwm_chip(chip); writel(1 << pwm->hwpwm, mxs->base + PWM_CTRL + CLR); clk_disable_unprepare(mxs->clk); }

Contributors

PersonTokensPropCommitsCommitProp
Shawn Guo50100.00%1100.00%
Total50100.00%1100.00%

static const struct pwm_ops mxs_pwm_ops = { .config = mxs_pwm_config, .enable = mxs_pwm_enable, .disable = mxs_pwm_disable, .owner = THIS_MODULE, };
static int mxs_pwm_probe(struct platform_device *pdev) { struct device_node *np = pdev->dev.of_node; struct mxs_pwm_chip *mxs; struct resource *res; int ret; mxs = devm_kzalloc(&pdev->dev, sizeof(*mxs), GFP_KERNEL); if (!mxs) return -ENOMEM; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); mxs->base = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(mxs->base)) return PTR_ERR(mxs->base); mxs->clk = devm_clk_get(&pdev->dev, NULL); if (IS_ERR(mxs->clk)) return PTR_ERR(mxs->clk); mxs->chip.dev = &pdev->dev; mxs->chip.ops = &mxs_pwm_ops; mxs->chip.base = -1; ret = of_property_read_u32(np, "fsl,pwm-number", &mxs->chip.npwm); if (ret < 0) { dev_err(&pdev->dev, "failed to get pwm number: %d\n", ret); return ret; } ret = pwmchip_add(&mxs->chip); if (ret < 0) { dev_err(&pdev->dev, "failed to add pwm chip %d\n", ret); return ret; } platform_set_drvdata(pdev, mxs); ret = stmp_reset_block(mxs->base); if (ret) goto pwm_remove; return 0; pwm_remove: pwmchip_remove(&mxs->chip); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
Shawn Guo24388.36%360.00%
Fabio Estevam228.00%120.00%
Thierry Reding103.64%120.00%
Total275100.00%5100.00%


static int mxs_pwm_remove(struct platform_device *pdev) { struct mxs_pwm_chip *mxs = platform_get_drvdata(pdev); return pwmchip_remove(&mxs->chip); }

Contributors

PersonTokensPropCommitsCommitProp
Shawn Guo2996.67%150.00%
Axel Lin13.33%150.00%
Total30100.00%2100.00%

static const struct of_device_id mxs_pwm_dt_ids[] = { { .compatible = "fsl,imx23-pwm", }, { /* sentinel */ } }; MODULE_DEVICE_TABLE(of, mxs_pwm_dt_ids); static struct platform_driver mxs_pwm_driver = { .driver = { .name = "mxs-pwm", .of_match_table = mxs_pwm_dt_ids, }, .probe = mxs_pwm_probe, .remove = mxs_pwm_remove, }; module_platform_driver(mxs_pwm_driver); MODULE_ALIAS("platform:mxs-pwm"); MODULE_AUTHOR("Shawn Guo <shawn.guo@linaro.org>"); MODULE_DESCRIPTION("Freescale MXS PWM Driver"); MODULE_LICENSE("GPL v2");

Overall Contributors

PersonTokensPropCommitsCommitProp
Shawn Guo83092.53%440.00%
Gaetan Hug313.46%110.00%
Fabio Estevam222.45%110.00%
Thierry Reding111.23%220.00%
Boris Brezillon20.22%110.00%
Axel Lin10.11%110.00%
Total897100.00%10100.00%
Directory: drivers/pwm
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