> Subject: [PATCHv9 1/4] pwm: Add Freescale FTM PWM driver support
>
> The FTM PWM device can be found on Vybrid VF610 Tower and Layerscape LS-1
> SoCs.
>
> Signed-off-by: Xiubo Li <li.xi...@freescale.com>
> ---
For this patch series,
Reviewed-by: Yuan Yao <yao.y...@freescale.com>
Thanks.
>
>
> Hi Thierry,
>
> For this version I just removed the big-endian mode support, and will add
> it in later separate patches.
>
>
> Changes in v9:
> - Remove the big-endian mode support.
>
> Changes in v7 ~ v8:
> - Mainly about big-endian mode support.
>
> [snip] v1~v6
>
>
>
> drivers/pwm/Kconfig | 10 +
> drivers/pwm/Makefile | 1 +
> drivers/pwm/pwm-fsl-ftm.c | 479
> ++++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 490 insertions(+)
> create mode 100644 drivers/pwm/pwm-fsl-ftm.c
>
> diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig index
> 6a2a1e0a..9a4c641 100644
> --- a/drivers/pwm/Kconfig
> +++ b/drivers/pwm/Kconfig
> @@ -80,6 +80,16 @@ config PWM_EP93XX
> To compile this driver as a module, choose M here: the module
> will be called pwm-ep93xx.
>
> +config PWM_FSL_FTM
> + tristate "Freescale FlexTimer Module (FTM) PWM support"
> + depends on OF
> + help
> + Generic FTM PWM framework driver for Freescale VF610 and
> + Layerscape LS-1 SoCs.
> +
> + To compile this driver as a module, choose M here: the module
> + will be called pwm-fsl-ftm.
> +
> config PWM_IMX
> tristate "i.MX PWM support"
> depends on ARCH_MXC
> diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile index
> 1b99cfb..c22905c 100644
> --- a/drivers/pwm/Makefile
> +++ b/drivers/pwm/Makefile
> @@ -5,6 +5,7 @@ obj-$(CONFIG_PWM_ATMEL) += pwm-atmel.o
> obj-$(CONFIG_PWM_ATMEL_TCB) += pwm-atmel-tcb.o
> obj-$(CONFIG_PWM_BFIN) += pwm-bfin.o
> obj-$(CONFIG_PWM_EP93XX) += pwm-ep93xx.o
> +obj-$(CONFIG_PWM_FSL_FTM) += pwm-fsl-ftm.o
> obj-$(CONFIG_PWM_IMX) += pwm-imx.o
> obj-$(CONFIG_PWM_JZ4740) += pwm-jz4740.o
> obj-$(CONFIG_PWM_LPC32XX) += pwm-lpc32xx.o
> diff --git a/drivers/pwm/pwm-fsl-ftm.c b/drivers/pwm/pwm-fsl-ftm.c new
> file mode 100644 index 0000000..60467b3
> --- /dev/null
> +++ b/drivers/pwm/pwm-fsl-ftm.c
> @@ -0,0 +1,479 @@
> +/*
> + * Freescale FlexTimer Module (FTM) PWM Driver
> + *
> + * Copyright 2012-2013 Freescale Semiconductor, Inc.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/err.h>
> +#include <linux/io.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/of_address.h>
> +#include <linux/platform_device.h>
> +#include <linux/pwm.h>
> +#include <linux/slab.h>
> +
> +#define FTM_SC 0x00
> +#define FTM_SC_CLK_MASK 0x3
> +#define FTM_SC_CLK_SHIFT 3
> +#define FTM_SC_CLK(c) (((c) + 1) << FTM_SC_CLK_SHIFT)
> +#define FTM_SC_PS_MASK 0x7
> +#define FTM_SC_PS_SHIFT 0
> +
> +#define FTM_CNT 0x04
> +#define FTM_MOD 0x08
> +
> +#define FTM_CSC_BASE 0x0C
> +#define FTM_CSC_MSB BIT(5)
> +#define FTM_CSC_MSA BIT(4)
> +#define FTM_CSC_ELSB BIT(3)
> +#define FTM_CSC_ELSA BIT(2)
> +#define FTM_CSC(_channel) (FTM_CSC_BASE + ((_channel) * 8))
> +
> +#define FTM_CV_BASE 0x10
> +#define FTM_CV(_channel) (FTM_CV_BASE + ((_channel) * 8))
> +
> +#define FTM_CNTIN 0x4C
> +#define FTM_STATUS 0x50
> +
> +#define FTM_MODE 0x54
> +#define FTM_MODE_FTMEN BIT(0)
> +#define FTM_MODE_INIT BIT(2)
> +#define FTM_MODE_PWMSYNC BIT(3)
> +
> +#define FTM_SYNC 0x58
> +#define FTM_OUTINIT 0x5C
> +#define FTM_OUTMASK 0x60
> +#define FTM_COMBINE 0x64
> +#define FTM_DEADTIME 0x68
> +#define FTM_EXTTRIG 0x6C
> +#define FTM_POL 0x70
> +#define FTM_FMS 0x74
> +#define FTM_FILTER 0x78
> +#define FTM_FLTCTRL 0x7C
> +#define FTM_QDCTRL 0x80
> +#define FTM_CONF 0x84
> +#define FTM_FLTPOL 0x88
> +#define FTM_SYNCONF 0x8C
> +#define FTM_INVCTRL 0x90
> +#define FTM_SWOCTRL 0x94
> +#define FTM_PWMLOAD 0x98
> +
> +enum fsl_pwm_clk {
> + FSL_PWM_CLK_SYS,
> + FSL_PWM_CLK_FIX,
> + FSL_PWM_CLK_EXT,
> +};
> +
> +struct fsl_pwm_chip {
> + struct pwm_chip chip;
> +
> + struct mutex lock;
> +
> + struct clk *sys_clk;
> + struct clk *counter_clk;
> + struct clk *counter_clk_en;
> + unsigned int counter_clk_select;
> + unsigned int counter_clk_enable;
> + unsigned int clk_ps;
> +
> + void __iomem *base;
> +
> + int period_ns;
> +};
> +
> +static inline struct fsl_pwm_chip *to_fsl_chip(struct pwm_chip *chip) {
> + return container_of(chip, struct fsl_pwm_chip, chip); }
> +
> +static int fsl_pwm_request(struct pwm_chip *chip, struct pwm_device
> +*pwm) {
> + struct fsl_pwm_chip *fpc = to_fsl_chip(chip);
> +
> + return clk_prepare_enable(fpc->sys_clk); }
> +
> +static void fsl_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
> +{
> + struct fsl_pwm_chip *fpc = to_fsl_chip(chip);
> +
> + clk_disable_unprepare(fpc->sys_clk);
> +}
> +
> +static int fsl_pwm_calculate_default_ps(struct fsl_pwm_chip *fpc,
> + enum fsl_pwm_clk index)
> +{
> + unsigned long sys_rate, cnt_rate;
> + unsigned long long ratio;
> +
> + sys_rate = clk_get_rate(fpc->sys_clk);
> + if (!sys_rate)
> + return -EINVAL;
> +
> + cnt_rate = clk_get_rate(fpc->counter_clk);
> + if (!cnt_rate)
> + return -EINVAL;
> +
> + switch (index) {
> + case FSL_PWM_CLK_SYS:
> + fpc->clk_ps = 1;
> + break;
> + case FSL_PWM_CLK_FIX:
> + ratio = 2 * cnt_rate - 1;
> + do_div(ratio, sys_rate);
> + fpc->clk_ps = ratio;
> + break;
> + case FSL_PWM_CLK_EXT:
> + ratio = 4 * cnt_rate - 1;
> + do_div(ratio, sys_rate);
> + fpc->clk_ps = ratio;
> + break;
> + }
> +
> + return 0;
> +}
> +
> +static unsigned long fsl_pwm_calculate_cycles(struct fsl_pwm_chip *fpc,
> + unsigned long period_ns)
> +{
> + unsigned long long c, c0;
> +
> + c = clk_get_rate(fpc->counter_clk);
> + c = c * period_ns;
> + do_div(c, 1000000000UL);
> +
> + do {
> + c0 = c;
> + do_div(c0, (1 << fpc->clk_ps));
> + if (c0 <= 0xFFFF)
> + return (unsigned long)c0;
> + } while (++fpc->clk_ps < 8);
> +
> + return 0;
> +}
> +
> +static unsigned long fsl_pwm_calculate_period_cycles(struct fsl_pwm_chip
> *fpc,
> + unsigned long period_ns,
> + enum fsl_pwm_clk index)
> +{
> + int ret;
> +
> + fpc->counter_clk_select = FTM_SC_CLK(index);
> +
> + ret = fsl_pwm_calculate_default_ps(fpc, index);
> + if (ret) {
> + dev_err(fpc->chip.dev, "failed to calculate default "
> + "prescaler: %d\n", ret);
> + return 0;
> + }
> +
> + return fsl_pwm_calculate_cycles(fpc, period_ns); }
> +
> +static unsigned long fsl_pwm_calculate_period(struct fsl_pwm_chip *fpc,
> + unsigned long period_ns)
> +{
> + struct clk *cnt_clk[3];
> + enum fsl_pwm_clk m0, m1;
> + unsigned long fix_rate, ext_rate, cycles;
> +
> + fpc->counter_clk = fpc->sys_clk;
> + cycles = fsl_pwm_calculate_period_cycles(fpc, period_ns,
> + FSL_PWM_CLK_SYS);
> + if (cycles)
> + return cycles;
> +
> + cnt_clk[FSL_PWM_CLK_FIX] = devm_clk_get(fpc->chip.dev, "ftm_fix");
> + if (IS_ERR(cnt_clk[FSL_PWM_CLK_FIX]))
> + return PTR_ERR(cnt_clk[FSL_PWM_CLK_FIX]);
> +
> + cnt_clk[FSL_PWM_CLK_EXT] = devm_clk_get(fpc->chip.dev, "ftm_ext");
> + if (IS_ERR(cnt_clk[FSL_PWM_CLK_EXT]))
> + return PTR_ERR(cnt_clk[FSL_PWM_CLK_EXT]);
> +
> + fpc->counter_clk_en = devm_clk_get(fpc->chip.dev, "ftm_cnt_clk_en");
> + if (IS_ERR(fpc->counter_clk_en))
> + return PTR_ERR(fpc->counter_clk_en);
> +
> + fix_rate = clk_get_rate(cnt_clk[FSL_PWM_CLK_FIX]);
> + ext_rate = clk_get_rate(cnt_clk[FSL_PWM_CLK_EXT]);
> +
> + if (fix_rate > ext_rate) {
> + m0 = FSL_PWM_CLK_FIX;
> + m1 = FSL_PWM_CLK_EXT;
> + } else {
> + m0 = FSL_PWM_CLK_EXT;
> + m1 = FSL_PWM_CLK_FIX;
> + }
> +
> + fpc->counter_clk = cnt_clk[m0];
> + cycles = fsl_pwm_calculate_period_cycles(fpc, period_ns, m0);
> + if (cycles)
> + return cycles;
> +
> + fpc->counter_clk = cnt_clk[m1];
> +
> + return fsl_pwm_calculate_period_cycles(fpc, period_ns, m0); }
> +
> +static unsigned long fsl_pwm_calculate_duty(struct fsl_pwm_chip *fpc,
> + unsigned long period_ns,
> + unsigned long duty_ns)
> +{
> + unsigned long long val, duty;
> +
> + val = readl(fpc->base + FTM_MOD);
> + duty = duty_ns * (val + 1);
> + do_div(duty, period_ns);
> +
> + return (unsigned long)duty;
> +}
> +
> +static int fsl_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
> + int duty_ns, int period_ns)
> +{
> + struct fsl_pwm_chip *fpc = to_fsl_chip(chip);
> + u32 val, period, duty;
> +
> + mutex_lock(&fpc->lock);
> +
> + /*
> + * The Freescale FTM controller supports only a single period for
> + * all PWM channels, therefore incompatible changes need to be
> + * refused.
> + */
> + if (fpc->period_ns && fpc->period_ns != period_ns) {
> + dev_err(fpc->chip.dev,
> + "conflicting period requested for PWM %u\n",
> + pwm->hwpwm);
> + mutex_unlock(&fpc->lock);
> + return -EBUSY;
> + }
> +
> + if (!fpc->period_ns && duty_ns) {
> + period = fsl_pwm_calculate_period(fpc, period_ns);
> + if (!period) {
> + dev_err(fpc->chip.dev, "failed to calculate period\n");
> + mutex_unlock(&fpc->lock);
> + return -EINVAL;
> + }
> +
> + val = readl(fpc->base + FTM_SC);
> + val &= ~(FTM_SC_PS_MASK << FTM_SC_PS_SHIFT);
> + val |= fpc->clk_ps;
> + writel(val, fpc->base + FTM_SC);
> + writel(period - 1, fpc->base + FTM_MOD);
> +
> + fpc->period_ns = period_ns;
> + }
> +
> + mutex_unlock(&fpc->lock);
> +
> + duty = fsl_pwm_calculate_duty(fpc, period_ns, duty_ns);
> +
> + writel(FTM_CSC_MSB | FTM_CSC_ELSB, fpc->base + FTM_CSC(pwm->hwpwm));
> + writel(duty, fpc->base + FTM_CV(pwm->hwpwm));
> +
> + return 0;
> +}
> +
> +static int fsl_pwm_set_polarity(struct pwm_chip *chip,
> + struct pwm_device *pwm,
> + enum pwm_polarity polarity)
> +{
> + struct fsl_pwm_chip *fpc = to_fsl_chip(chip);
> + u32 val;
> +
> + val = readl(fpc->base + FTM_POL);
> +
> + if (polarity == PWM_POLARITY_INVERSED)
> + val |= BIT(pwm->hwpwm);
> + else
> + val &= ~BIT(pwm->hwpwm);
> +
> + writel(val, fpc->base + FTM_POL);
> +
> + return 0;
> +}
> +
> +static int fsl_counter_clock_enable(struct fsl_pwm_chip *fpc) {
> + u32 val;
> + int ret;
> +
> + if (fpc->counter_clk_enable++)
> + return 0;
> +
> + ret = clk_prepare_enable(fpc->counter_clk);
> + if (ret) {
> + fpc->counter_clk_enable--;
> + return ret;
> + }
> +
> + ret = clk_prepare_enable(fpc->counter_clk_en);
> + if (ret) {
> + fpc->counter_clk_enable--;
> + return ret;
> + }
> +
> + /* select counter clock source */
> + val = readl(fpc->base + FTM_SC);
> + val &= ~(FTM_SC_CLK_MASK << FTM_SC_CLK_SHIFT);
> + val |= fpc->counter_clk_select;
> + writel(val, fpc->base + FTM_SC);
> +
> + return 0;
> +}
> +
> +static int fsl_pwm_enable(struct pwm_chip *chip, struct pwm_device
> +*pwm) {
> + struct fsl_pwm_chip *fpc = to_fsl_chip(chip);
> + u32 val;
> + int ret;
> +
> + val = readl(fpc->base + FTM_OUTMASK);
> + val &= ~BIT(pwm->hwpwm);
> + writel(val, fpc->base + FTM_OUTMASK);
> +
> + mutex_lock(&fpc->lock);
> + ret = fsl_counter_clock_enable(fpc);
> + mutex_unlock(&fpc->lock);
> +
> + return ret;
> +}
> +
> +static void fsl_counter_clock_disable(struct fsl_pwm_chip *fpc) {
> + u32 val;
> +
> + if (--fpc->counter_clk_enable)
> + return;
> +
> + val = readl(fpc->base + FTM_SC);
> + val &= ~(FTM_SC_CLK_MASK << FTM_SC_CLK_SHIFT);
> + writel(val, fpc->base + FTM_SC);
> +
> + clk_disable_unprepare(fpc->counter_clk_en);
> + clk_disable_unprepare(fpc->counter_clk);
> +}
> +
> +static void fsl_pwm_disable(struct pwm_chip *chip, struct pwm_device
> +*pwm) {
> + struct fsl_pwm_chip *fpc = to_fsl_chip(chip);
> + u32 val;
> +
> + val = readl(fpc->base + FTM_OUTMASK);
> + val |= BIT(pwm->hwpwm);
> + writel(val, fpc->base + FTM_OUTMASK);
> +
> + mutex_lock(&fpc->lock);
> +
> + fsl_counter_clock_disable(fpc);
> +
> + val = readl(fpc->base + FTM_OUTMASK);
> +
> + if ((val & 0xFF) == 0xFF) {
> + fpc->period_ns = 0;
> + fpc->counter_clk_en = NULL;
> + }
> +
> + mutex_unlock(&fpc->lock);
> +}
> +
> +static const struct pwm_ops fsl_pwm_ops = {
> + .request = fsl_pwm_request,
> + .free = fsl_pwm_free,
> + .config = fsl_pwm_config,
> + .set_polarity = fsl_pwm_set_polarity,
> + .enable = fsl_pwm_enable,
> + .disable = fsl_pwm_disable,
> + .owner = THIS_MODULE,
> +};
> +
> +static int fsl_pwm_probe(struct platform_device *pdev) {
> + struct fsl_pwm_chip *fpc;
> + struct resource *res;
> + int ret;
> +
> + fpc = devm_kzalloc(&pdev->dev, sizeof(*fpc), GFP_KERNEL);
> + if (!fpc)
> + return -ENOMEM;
> +
> + mutex_init(&fpc->lock);
> +
> + fpc->chip.dev = &pdev->dev;
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + fpc->base = devm_ioremap_resource(&pdev->dev, res);
> + if (IS_ERR(fpc->base))
> + return PTR_ERR(fpc->base);
> +
> + fpc->sys_clk = devm_clk_get(&pdev->dev, "ftm_sys");
> + if (IS_ERR(fpc->sys_clk)) {
> + dev_err(&pdev->dev,
> + "failed to get \"ftm_sys\" clock\n");
> + return PTR_ERR(fpc->sys_clk);
> + }
> +
> + ret = clk_prepare_enable(fpc->sys_clk);
> + if (ret)
> + return ret;
> +
> + writel(0x00, fpc->base + FTM_CNTIN);
> + writel(0x00, fpc->base + FTM_OUTINIT);
> + writel(0xFF, fpc->base + FTM_OUTMASK);
> + clk_disable_unprepare(fpc->sys_clk);
> +
> + fpc->chip.ops = &fsl_pwm_ops;
> + fpc->chip.of_xlate = of_pwm_xlate_with_flags;
> + fpc->chip.of_pwm_n_cells = 3;
> + fpc->chip.base = -1;
> + fpc->chip.npwm = 8;
> +
> + ret = pwmchip_add(&fpc->chip);
> + if (ret < 0) {
> + dev_err(&pdev->dev, "failed to add PWM chip : %d\n", ret);
> + return ret;
> + }
> +
> + platform_set_drvdata(pdev, fpc);
> +
> + return 0;
> +}
> +
> +static int fsl_pwm_remove(struct platform_device *pdev) {
> + struct fsl_pwm_chip *fpc = platform_get_drvdata(pdev);
> +
> + return pwmchip_remove(&fpc->chip);
> +}
> +
> +static const struct of_device_id fsl_pwm_dt_ids[] = {
> + { .compatible = "fsl,vf610-ftm-pwm", },
> + { /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, fsl_pwm_dt_ids);
> +
> +static struct platform_driver fsl_pwm_driver = {
> + .driver = {
> + .name = "fsl-ftm-pwm",
> + .of_match_table = fsl_pwm_dt_ids,
> + },
> + .probe = fsl_pwm_probe,
> + .remove = fsl_pwm_remove,
> +};
> +module_platform_driver(fsl_pwm_driver);
> +
> +MODULE_DESCRIPTION("Freescale FlexTimer Module PWM Driver");
> +MODULE_AUTHOR("Xiubo Li <li.xi...@freescale.com>");
> +MODULE_ALIAS("platform:fsl-ftm-pwm");
> +MODULE_LICENSE("GPL");
> --
> 1.8.4
>
>
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