lkml.org 
[lkml]   [2017]   [May]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 52/58] PWM: atmel-tcb: switch to new binding
    Date
    The PWM is now a subnode of the used TCB. This is cleaner and it mainly
    allows to stop wasting TCB channels when only 4 PWMs are used.

    Cc: Thierry Reding <thierry.reding@gmail.com>
    Cc: linux-pwm@vger.kernel.org
    Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
    ---
    drivers/pwm/Kconfig | 3 +-
    drivers/pwm/pwm-atmel-tcb.c | 221 ++++++++++++++++++++++++--------------------
    2 files changed, 122 insertions(+), 102 deletions(-)

    diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
    index 313c10789ca2..d154f1fb610e 100644
    --- a/drivers/pwm/Kconfig
    +++ b/drivers/pwm/Kconfig
    @@ -64,7 +64,8 @@ config PWM_ATMEL_HLCDC_PWM

    config PWM_ATMEL_TCB
    tristate "Atmel TC Block PWM support"
    - depends on ATMEL_TCLIB && OF
    + depends on OF
    + select REGMAP_MMIO
    help
    Generic PWM framework driver for Atmel Timer Counter Block.

    diff --git a/drivers/pwm/pwm-atmel-tcb.c b/drivers/pwm/pwm-atmel-tcb.c
    index 75db585a2a94..9aa569835b97 100644
    --- a/drivers/pwm/pwm-atmel-tcb.c
    +++ b/drivers/pwm/pwm-atmel-tcb.c
    @@ -16,19 +16,26 @@
    #include <linux/err.h>
    #include <linux/ioport.h>
    #include <linux/io.h>
    +#include <linux/mfd/syscon.h>
    #include <linux/platform_device.h>
    -#include <linux/atmel_tc.h>
    #include <linux/pwm.h>
    #include <linux/of_device.h>
    +#include <linux/of_irq.h>
    +#include <linux/regmap.h>
    #include <linux/slab.h>
    +#include <soc/at91/atmel_tcb.h>

    -#define NPWM 6
    +#define NPWM 2

    -#define ATMEL_TC_ACMR_MASK (ATMEL_TC_ACPA | ATMEL_TC_ACPC | \
    - ATMEL_TC_AEEVT | ATMEL_TC_ASWTRG)
    +#define ATMEL_TC_ACMR_MASK (ATMEL_TC_CMR_ACPA_MSK | \
    + ATMEL_TC_CMR_ACPC_MSK | \
    + ATMEL_TC_CMR_AEEVT_MSK | \
    + ATMEL_TC_CMR_ASWTRG_MSK)

    -#define ATMEL_TC_BCMR_MASK (ATMEL_TC_BCPB | ATMEL_TC_BCPC | \
    - ATMEL_TC_BEEVT | ATMEL_TC_BSWTRG)
    +#define ATMEL_TC_BCMR_MASK (ATMEL_TC_CMR_BCPB_MSK | \
    + ATMEL_TC_CMR_BCPC_MSK | \
    + ATMEL_TC_CMR_BEEVT_MSK | \
    + ATMEL_TC_CMR_BSWTRG_MSK)

    struct atmel_tcb_pwm_device {
    enum pwm_polarity polarity; /* PWM polarity */
    @@ -40,7 +47,11 @@ struct atmel_tcb_pwm_device {
    struct atmel_tcb_pwm_chip {
    struct pwm_chip chip;
    spinlock_t lock;
    - struct atmel_tc *tc;
    + u8 channel;
    + u8 width;
    + struct regmap *regmap;
    + struct clk *clk;
    + struct clk *slow_clk;
    struct atmel_tcb_pwm_device *pwms[NPWM];
    };

    @@ -65,10 +76,6 @@ static int atmel_tcb_pwm_request(struct pwm_chip *chip,
    {
    struct atmel_tcb_pwm_chip *tcbpwmc = to_tcb_chip(chip);
    struct atmel_tcb_pwm_device *tcbpwm;
    - struct atmel_tc *tc = tcbpwmc->tc;
    - void __iomem *regs = tc->regs;
    - unsigned group = pwm->hwpwm / 2;
    - unsigned index = pwm->hwpwm % 2;
    unsigned cmr;
    int ret;

    @@ -76,7 +83,7 @@ static int atmel_tcb_pwm_request(struct pwm_chip *chip,
    if (!tcbpwm)
    return -ENOMEM;

    - ret = clk_prepare_enable(tc->clk[group]);
    + ret = clk_prepare_enable(tcbpwmc->clk);
    if (ret) {
    devm_kfree(chip->dev, tcbpwm);
    return ret;
    @@ -89,28 +96,32 @@ static int atmel_tcb_pwm_request(struct pwm_chip *chip,
    tcbpwm->div = 0;

    spin_lock(&tcbpwmc->lock);
    - cmr = __raw_readl(regs + ATMEL_TC_REG(group, CMR));
    + regmap_read(tcbpwmc->regmap, ATMEL_TC_CMR(tcbpwmc->channel), &cmr);
    /*
    * Get init config from Timer Counter registers if
    * Timer Counter is already configured as a PWM generator.
    */
    - if (cmr & ATMEL_TC_WAVE) {
    - if (index == 0)
    - tcbpwm->duty =
    - __raw_readl(regs + ATMEL_TC_REG(group, RA));
    + if (cmr & ATMEL_TC_CMR_WAVE) {
    + if (pwm->hwpwm == 0)
    + regmap_read(tcbpwmc->regmap,
    + ATMEL_TC_RA(tcbpwmc->channel),
    + &tcbpwm->duty);
    else
    - tcbpwm->duty =
    - __raw_readl(regs + ATMEL_TC_REG(group, RB));
    -
    - tcbpwm->div = cmr & ATMEL_TC_TCCLKS;
    - tcbpwm->period = __raw_readl(regs + ATMEL_TC_REG(group, RC));
    - cmr &= (ATMEL_TC_TCCLKS | ATMEL_TC_ACMR_MASK |
    + regmap_read(tcbpwmc->regmap,
    + ATMEL_TC_RB(tcbpwmc->channel),
    + &tcbpwm->duty);
    +
    + tcbpwm->div = cmr & ATMEL_TC_CMR_TCLKS_MSK;
    + regmap_read(tcbpwmc->regmap, ATMEL_TC_RC(tcbpwmc->channel),
    + &tcbpwm->period);
    + cmr &= (ATMEL_TC_CMR_TCLKS_MSK | ATMEL_TC_ACMR_MASK |
    ATMEL_TC_BCMR_MASK);
    } else
    cmr = 0;

    - cmr |= ATMEL_TC_WAVE | ATMEL_TC_WAVESEL_UP_AUTO | ATMEL_TC_EEVT_XC0;
    - __raw_writel(cmr, regs + ATMEL_TC_REG(group, CMR));
    + cmr |= ATMEL_TC_CMR_WAVE | ATMEL_TC_CMR_WAVESEL_UPRC |
    + ATMEL_TC_CMR_EEVT_XC(0);
    + regmap_write(tcbpwmc->regmap, ATMEL_TC_CMR(tcbpwmc->channel), cmr);
    spin_unlock(&tcbpwmc->lock);

    tcbpwmc->pwms[pwm->hwpwm] = tcbpwm;
    @@ -122,9 +133,8 @@ static void atmel_tcb_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
    {
    struct atmel_tcb_pwm_chip *tcbpwmc = to_tcb_chip(chip);
    struct atmel_tcb_pwm_device *tcbpwm = pwm_get_chip_data(pwm);
    - struct atmel_tc *tc = tcbpwmc->tc;

    - clk_disable_unprepare(tc->clk[pwm->hwpwm / 2]);
    + clk_disable_unprepare(tcbpwmc->clk);
    tcbpwmc->pwms[pwm->hwpwm] = NULL;
    devm_kfree(chip->dev, tcbpwm);
    }
    @@ -133,10 +143,6 @@ static void atmel_tcb_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
    {
    struct atmel_tcb_pwm_chip *tcbpwmc = to_tcb_chip(chip);
    struct atmel_tcb_pwm_device *tcbpwm = pwm_get_chip_data(pwm);
    - struct atmel_tc *tc = tcbpwmc->tc;
    - void __iomem *regs = tc->regs;
    - unsigned group = pwm->hwpwm / 2;
    - unsigned index = pwm->hwpwm % 2;
    unsigned cmr;
    enum pwm_polarity polarity = tcbpwm->polarity;

    @@ -152,35 +158,35 @@ static void atmel_tcb_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
    polarity = !polarity;

    spin_lock(&tcbpwmc->lock);
    - cmr = __raw_readl(regs + ATMEL_TC_REG(group, CMR));
    + regmap_read(tcbpwmc->regmap, ATMEL_TC_CMR(tcbpwmc->channel), &cmr);

    /* flush old setting and set the new one */
    - if (index == 0) {
    + if (pwm->hwpwm == 0) {
    cmr &= ~ATMEL_TC_ACMR_MASK;
    if (polarity == PWM_POLARITY_INVERSED)
    - cmr |= ATMEL_TC_ASWTRG_CLEAR;
    + cmr |= ATMEL_TC_CMR_ASWTRG(CLEAR);
    else
    - cmr |= ATMEL_TC_ASWTRG_SET;
    + cmr |= ATMEL_TC_CMR_ASWTRG(SET);
    } else {
    cmr &= ~ATMEL_TC_BCMR_MASK;
    if (polarity == PWM_POLARITY_INVERSED)
    - cmr |= ATMEL_TC_BSWTRG_CLEAR;
    + cmr |= ATMEL_TC_CMR_BSWTRG(CLEAR);
    else
    - cmr |= ATMEL_TC_BSWTRG_SET;
    + cmr |= ATMEL_TC_CMR_BSWTRG(SET);
    }

    - __raw_writel(cmr, regs + ATMEL_TC_REG(group, CMR));
    + regmap_write(tcbpwmc->regmap, ATMEL_TC_CMR(tcbpwmc->channel), cmr);

    /*
    * Use software trigger to apply the new setting.
    * If both PWM devices in this group are disabled we stop the clock.
    */
    - if (!(cmr & (ATMEL_TC_ACPC | ATMEL_TC_BCPC)))
    - __raw_writel(ATMEL_TC_SWTRG | ATMEL_TC_CLKDIS,
    - regs + ATMEL_TC_REG(group, CCR));
    + if (!(cmr & (ATMEL_TC_CMR_ACPC_MSK | ATMEL_TC_CMR_BCPC_MSK)))
    + regmap_write(tcbpwmc->regmap, ATMEL_TC_CCR(tcbpwmc->channel),
    + ATMEL_TC_CCR_SWTRG | ATMEL_TC_CCR_CLKDIS);
    else
    - __raw_writel(ATMEL_TC_SWTRG, regs +
    - ATMEL_TC_REG(group, CCR));
    + regmap_write(tcbpwmc->regmap, ATMEL_TC_CCR(tcbpwmc->channel),
    + ATMEL_TC_CCR_SWTRG);

    spin_unlock(&tcbpwmc->lock);
    }
    @@ -189,10 +195,6 @@ static int atmel_tcb_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
    {
    struct atmel_tcb_pwm_chip *tcbpwmc = to_tcb_chip(chip);
    struct atmel_tcb_pwm_device *tcbpwm = pwm_get_chip_data(pwm);
    - struct atmel_tc *tc = tcbpwmc->tc;
    - void __iomem *regs = tc->regs;
    - unsigned group = pwm->hwpwm / 2;
    - unsigned index = pwm->hwpwm % 2;
    u32 cmr;
    enum pwm_polarity polarity = tcbpwm->polarity;

    @@ -208,25 +210,25 @@ static int atmel_tcb_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
    polarity = !polarity;

    spin_lock(&tcbpwmc->lock);
    - cmr = __raw_readl(regs + ATMEL_TC_REG(group, CMR));
    + regmap_read(tcbpwmc->regmap, ATMEL_TC_CMR(tcbpwmc->channel), &cmr);

    /* flush old setting and set the new one */
    - cmr &= ~ATMEL_TC_TCCLKS;
    + cmr &= ~ATMEL_TC_CMR_TCLKS_MSK;

    - if (index == 0) {
    + if (pwm->hwpwm == 0) {
    cmr &= ~ATMEL_TC_ACMR_MASK;

    /* Set CMR flags according to given polarity */
    if (polarity == PWM_POLARITY_INVERSED)
    - cmr |= ATMEL_TC_ASWTRG_CLEAR;
    + cmr |= ATMEL_TC_CMR_ASWTRG(CLEAR);
    else
    - cmr |= ATMEL_TC_ASWTRG_SET;
    + cmr |= ATMEL_TC_CMR_ASWTRG(SET);
    } else {
    cmr &= ~ATMEL_TC_BCMR_MASK;
    if (polarity == PWM_POLARITY_INVERSED)
    - cmr |= ATMEL_TC_BSWTRG_CLEAR;
    + cmr |= ATMEL_TC_CMR_BSWTRG(CLEAR);
    else
    - cmr |= ATMEL_TC_BSWTRG_SET;
    + cmr |= ATMEL_TC_CMR_BSWTRG(SET);
    }

    /*
    @@ -236,33 +238,40 @@ static int atmel_tcb_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
    * this config till next config call.
    */
    if (tcbpwm->duty != tcbpwm->period && tcbpwm->duty > 0) {
    - if (index == 0) {
    + if (pwm->hwpwm == 0) {
    if (polarity == PWM_POLARITY_INVERSED)
    - cmr |= ATMEL_TC_ACPA_SET | ATMEL_TC_ACPC_CLEAR;
    + cmr |= ATMEL_TC_CMR_ACPA(SET) |
    + ATMEL_TC_CMR_ACPC(CLEAR);
    else
    - cmr |= ATMEL_TC_ACPA_CLEAR | ATMEL_TC_ACPC_SET;
    + cmr |= ATMEL_TC_CMR_ACPA(CLEAR) |
    + ATMEL_TC_CMR_ACPC(SET);
    } else {
    if (polarity == PWM_POLARITY_INVERSED)
    - cmr |= ATMEL_TC_BCPB_SET | ATMEL_TC_BCPC_CLEAR;
    + cmr |= ATMEL_TC_CMR_BCPB(SET) |
    + ATMEL_TC_CMR_BCPC(CLEAR);
    else
    - cmr |= ATMEL_TC_BCPB_CLEAR | ATMEL_TC_BCPC_SET;
    + cmr |= ATMEL_TC_CMR_BCPB(CLEAR) |
    + ATMEL_TC_CMR_BCPC(SET);
    }
    }

    - cmr |= (tcbpwm->div & ATMEL_TC_TCCLKS);
    + cmr |= (tcbpwm->div & ATMEL_TC_CMR_TCLKS_MSK);

    - __raw_writel(cmr, regs + ATMEL_TC_REG(group, CMR));
    + regmap_write(tcbpwmc->regmap, ATMEL_TC_CMR(tcbpwmc->channel), cmr);

    - if (index == 0)
    - __raw_writel(tcbpwm->duty, regs + ATMEL_TC_REG(group, RA));
    + if (pwm->hwpwm == 0)
    + regmap_write(tcbpwmc->regmap, ATMEL_TC_RA(tcbpwmc->channel),
    + tcbpwm->duty);
    else
    - __raw_writel(tcbpwm->duty, regs + ATMEL_TC_REG(group, RB));
    + regmap_write(tcbpwmc->regmap, ATMEL_TC_RB(tcbpwmc->channel),
    + tcbpwm->duty);

    - __raw_writel(tcbpwm->period, regs + ATMEL_TC_REG(group, RC));
    + regmap_write(tcbpwmc->regmap, ATMEL_TC_RC(tcbpwmc->channel),
    + tcbpwm->period);

    /* Use software trigger to apply the new setting */
    - __raw_writel(ATMEL_TC_CLKEN | ATMEL_TC_SWTRG,
    - regs + ATMEL_TC_REG(group, CCR));
    + regmap_write(tcbpwmc->regmap, ATMEL_TC_CCR(tcbpwmc->channel),
    + ATMEL_TC_CCR_SWTRG | ATMEL_TC_CCR_CLKEN);
    spin_unlock(&tcbpwmc->lock);
    return 0;
    }
    @@ -272,15 +281,12 @@ static int atmel_tcb_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
    {
    struct atmel_tcb_pwm_chip *tcbpwmc = to_tcb_chip(chip);
    struct atmel_tcb_pwm_device *tcbpwm = pwm_get_chip_data(pwm);
    - unsigned group = pwm->hwpwm / 2;
    - unsigned index = pwm->hwpwm % 2;
    struct atmel_tcb_pwm_device *atcbpwm = NULL;
    - struct atmel_tc *tc = tcbpwmc->tc;
    int i;
    int slowclk = 0;
    unsigned period;
    unsigned duty;
    - unsigned rate = clk_get_rate(tc->clk[group]);
    + unsigned rate = clk_get_rate(tcbpwmc->clk);
    unsigned long long min;
    unsigned long long max;

    @@ -294,7 +300,7 @@ static int atmel_tcb_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
    continue;
    }
    min = div_u64((u64)NSEC_PER_SEC * atmel_tc_divisors[i], rate);
    - max = min << tc->tcb_config->counter_width;
    + max = min << tcbpwmc->width;
    if (max >= period_ns)
    break;
    }
    @@ -305,9 +311,9 @@ static int atmel_tcb_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
    */
    if (i == 5) {
    i = slowclk;
    - rate = clk_get_rate(tc->slow_clk);
    + rate = clk_get_rate(tcbpwmc->slow_clk);
    min = div_u64(NSEC_PER_SEC, rate);
    - max = min << tc->tcb_config->counter_width;
    + max = min << tcbpwmc->width;

    /* If period is too big return ERANGE error */
    if (max < period_ns)
    @@ -317,17 +323,13 @@ static int atmel_tcb_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
    duty = div_u64(duty_ns, min);
    period = div_u64(period_ns, min);

    - if (index == 0)
    - atcbpwm = tcbpwmc->pwms[pwm->hwpwm + 1];
    + if (pwm->hwpwm == 0)
    + atcbpwm = tcbpwmc->pwms[1];
    else
    - atcbpwm = tcbpwmc->pwms[pwm->hwpwm - 1];
    + atcbpwm = tcbpwmc->pwms[0];

    /*
    - * PWM devices provided by TCB driver are grouped by 2:
    - * - group 0: PWM 0 & 1
    - * - group 1: PWM 2 & 3
    - * - group 2: PWM 4 & 5
    - *
    + * PWM devices provided by the TCB driver are grouped by 2.
    * PWM devices in a given group must be configured with the
    * same period_ns.
    *
    @@ -365,31 +367,41 @@ static const struct pwm_ops atmel_tcb_pwm_ops = {

    static int atmel_tcb_pwm_probe(struct platform_device *pdev)
    {
    + const struct of_device_id *match;
    + const struct atmel_tcb_info *tcb_info;
    struct atmel_tcb_pwm_chip *tcbpwm;
    struct device_node *np = pdev->dev.of_node;
    - struct atmel_tc *tc;
    + struct regmap *regmap;
    + struct clk *clk;
    + struct clk *slow_clk;
    int err;
    - int tcblock;
    + int channel;

    - err = of_property_read_u32(np, "tc-block", &tcblock);
    + err = of_property_read_u32(np, "reg", &channel);
    if (err < 0) {
    dev_err(&pdev->dev,
    - "failed to get Timer Counter Block number from device tree (error: %d)\n",
    + "failed to get Timer Counter Block channel from device tree (error: %d)\n",
    err);
    return err;
    }

    - tc = atmel_tc_alloc(tcblock);
    - if (tc == NULL) {
    - dev_err(&pdev->dev, "failed to allocate Timer Counter Block\n");
    - return -ENOMEM;
    - }
    + regmap = syscon_node_to_regmap(np->parent);
    + if (IS_ERR(regmap))
    + return PTR_ERR(regmap);
    +
    + slow_clk = of_clk_get_by_name(np->parent, "slow_clk");
    + if (IS_ERR(slow_clk))
    + return PTR_ERR(slow_clk);
    +
    + clk = tcb_clk_get(np, channel);
    + if (IS_ERR(clk))
    + return PTR_ERR(clk);

    tcbpwm = devm_kzalloc(&pdev->dev, sizeof(*tcbpwm), GFP_KERNEL);
    if (tcbpwm == NULL) {
    err = -ENOMEM;
    dev_err(&pdev->dev, "failed to allocate memory\n");
    - goto err_free_tc;
    + goto err_slow_clk;
    }

    tcbpwm->chip.dev = &pdev->dev;
    @@ -398,11 +410,18 @@ static int atmel_tcb_pwm_probe(struct platform_device *pdev)
    tcbpwm->chip.of_pwm_n_cells = 3;
    tcbpwm->chip.base = -1;
    tcbpwm->chip.npwm = NPWM;
    - tcbpwm->tc = tc;
    + tcbpwm->channel = channel;
    + tcbpwm->regmap = regmap;
    + tcbpwm->clk = clk;
    + tcbpwm->slow_clk = slow_clk;

    - err = clk_prepare_enable(tc->slow_clk);
    + match = of_match_node(atmel_tcb_dt_ids, np->parent);
    + tcb_info = match->data;
    + tcbpwm->width = tcb_info->bits;
    +
    + err = clk_prepare_enable(slow_clk);
    if (err)
    - goto err_free_tc;
    + goto err_slow_clk;

    spin_lock_init(&tcbpwm->lock);

    @@ -415,10 +434,10 @@ static int atmel_tcb_pwm_probe(struct platform_device *pdev)
    return 0;

    err_disable_clk:
    - clk_disable_unprepare(tcbpwm->tc->slow_clk);
    + clk_disable_unprepare(tcbpwm->slow_clk);

    -err_free_tc:
    - atmel_tc_free(tc);
    +err_slow_clk:
    + clk_put(slow_clk);

    return err;
    }
    @@ -428,14 +447,14 @@ static int atmel_tcb_pwm_remove(struct platform_device *pdev)
    struct atmel_tcb_pwm_chip *tcbpwm = platform_get_drvdata(pdev);
    int err;

    - clk_disable_unprepare(tcbpwm->tc->slow_clk);
    + clk_disable_unprepare(tcbpwm->slow_clk);
    + clk_put(tcbpwm->slow_clk);
    + clk_put(tcbpwm->clk);

    err = pwmchip_remove(&tcbpwm->chip);
    if (err < 0)
    return err;

    - atmel_tc_free(tcbpwm->tc);
    -
    return 0;
    }

    --
    2.11.0
    \
     
     \ /
      Last update: 2017-05-30 23:55    [W:4.361 / U:0.012 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site