RE: [PATCHv9 1/4] pwm: Add Freescale FTM PWM driver support

From: Li.Xiubo@xxxxxxxxxxxxx
Date: Wed Feb 19 2014 - 04:27:23 EST

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> Subject: RE: [PATCHv9 1/4] pwm: Add Freescale FTM PWM driver support
>
> > 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.Xiubo@xxxxxxxxxxxxx>
> > ---
>
> For this patch series,
> Reviewed-by: Yuan Yao <yao.yuan@xxxxxxxxxxxxx>
>
>

Thanks for your reply very much.

And the following information had been missing and should be added too:
Signed-off-by: Alison Wang <b18965@xxxxxxxxxxxxx>
Signed-off-by: Jingchang Lu <b35083@xxxxxxxxxxxxx>
Reviewed-by: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>

Thanks,

--
Best Regards,
Xiubo

> 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.Xiubo@xxxxxxxxxxxxx>");
> > +MODULE_ALIAS("platform:fsl-ftm-pwm");
> > +MODULE_LICENSE("GPL");
> > --
> > 1.8.4
> >
> >
> > --
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> > Please read the FAQ at http://www.tux.org/lkml/
> >

Next message: Jan Kara: "Re: [PATCH] backing_dev: Fix hung task on sync"
Previous message: Vlastimil Babka: "Re: [PATCH akpm] mm: include VM_MIXEDMAP flag in the VM_SPECIAL list to avoid m(un)locking"
In reply to: Yao Yuan: "RE: [PATCHv9 1/4] pwm: Add Freescale FTM PWM driver support"
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