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    SubjectRe: [PATCH v2 2/7] pwm: add support for atmel-hlcdc-pwm device


    On 06/09/2014 06:04 PM, Boris BREZILLON wrote:
    > The HLCDC IP available in some Atmel SoCs (i.e. sam9x5i.e. at91sam9n12,
    > at91sam9x5 family or sama5d3 family) provide a PWM device.
    >
    > This driver add support for this PWM device.
    >
    > Signed-off-by: Boris BREZILLON <boris.brezillon@free-electrons.com>
    > ---
    > .../devicetree/bindings/pwm/atmel-hlcdc-pwm.txt | 40 ++++
    > drivers/pwm/Kconfig | 9 +
    > drivers/pwm/Makefile | 1 +
    > drivers/pwm/pwm-atmel-hlcdc.c | 216 +++++++++++++++++++++
    > 4 files changed, 266 insertions(+)
    > create mode 100644 Documentation/devicetree/bindings/pwm/atmel-hlcdc-pwm.txt
    > create mode 100644 drivers/pwm/pwm-atmel-hlcdc.c
    >
    > diff --git a/Documentation/devicetree/bindings/pwm/atmel-hlcdc-pwm.txt b/Documentation/devicetree/bindings/pwm/atmel-hlcdc-pwm.txt
    > new file mode 100644
    > index 0000000..5e2ba87
    > --- /dev/null
    > +++ b/Documentation/devicetree/bindings/pwm/atmel-hlcdc-pwm.txt
    > @@ -0,0 +1,40 @@
    > +Device-Tree bindings for Atmel's HLCDC (High LCD Controller) PWM driver
    > +
    > +The Atmel HLCDC PWM is subdevice of the HLCDC MFD device.
    > +See Documentation/devicetree/bindings/mfd/atmel-hlcdc.txt for more details.
    > +
    > +Required properties:
    > + - compatible: value should be one of the following:
    > + "atmel,hlcdc-pwm"
    > + - pinctr-names: the pin control state names. Should contain "default".
    > + - pinctrl-0: should contain the pinctrl states described by pinctrl
    > + default.
    > + - #pwm-cells: should be set to 3.
    > +
    > +Example:
    > +
    > + hlcdc: hlcdc@f0030000 {
    > + compatible = "atmel,sama5d3-hlcdc";
    > + reg = <0xf0030000 0x2000>;
    > + clocks = <&lcdc_clk>, <&lcdck>, <&clk32k>;
    > + clock-names = "periph_clk","sys_clk", "slow_clk";
    > + status = "disabled";
    > +
    > + hlcdc-display-controller {
    > + compatible = "atmel,hlcdc-dc";
    > + interrupts = <36 IRQ_TYPE_LEVEL_HIGH 0>;
    > + pinctrl-names = "default", "rgb-444", "rgb-565", "rgb-666", "rgb-888";
    > + pinctrl-0 = <&pinctrl_lcd_base>;
    > + pinctrl-1 = <&pinctrl_lcd_base &pinctrl_lcd_rgb444>;
    > + pinctrl-2 = <&pinctrl_lcd_base &pinctrl_lcd_rgb565>;
    > + pinctrl-3 = <&pinctrl_lcd_base &pinctrl_lcd_rgb666>;
    > + pinctrl-4 = <&pinctrl_lcd_base &pinctrl_lcd_rgb888>;
    > + };
    > +
    > + hlcdc_pwm: hlcdc-pwm {
    > + compatible = "atmel,hlcdc-pwm";
    > + pinctrl-names = "default";
    > + pinctrl-0 = <&pinctrl_lcd_pwm>;
    > + #pwm-cells = <3>;
    > + };
    > + };
    > diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
    > index 5b34ff2..7186242 100644
    > --- a/drivers/pwm/Kconfig
    > +++ b/drivers/pwm/Kconfig
    > @@ -50,6 +50,15 @@ config PWM_ATMEL
    > To compile this driver as a module, choose M here: the module
    > will be called pwm-atmel.
    >
    > +config PWM_ATMEL_HLCDC_PWM
    > + tristate "Atmel HLCDC PWM support"
    > + depends on MFD_ATMEL_HLCDC
    I'd personnaly prefer a 'select' instead of 'depends on' here. Or maybe
    the MFD driver should enabled y defaut for platforms supporting the hlcdc.
    > + help
    > + Generic PWM framework driver for Atmel HLCDC PWM.
    > +
    > + To compile this driver as a module, choose M here: the module
    > + will be called pwm-atmel.
    > +
    > config PWM_ATMEL_TCB
    > tristate "Atmel TC Block PWM support"
    > depends on ATMEL_TCLIB && OF
    > diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile
    > index e57d2c3..a245519 100644
    > --- a/drivers/pwm/Makefile
    > +++ b/drivers/pwm/Makefile
    > @@ -2,6 +2,7 @@ obj-$(CONFIG_PWM) += core.o
    > obj-$(CONFIG_PWM_SYSFS) += sysfs.o
    > obj-$(CONFIG_PWM_AB8500) += pwm-ab8500.o
    > obj-$(CONFIG_PWM_ATMEL) += pwm-atmel.o
    > +obj-$(CONFIG_PWM_ATMEL_HLCDC_PWM) += pwm-atmel-hlcdc.o
    > obj-$(CONFIG_PWM_ATMEL_TCB) += pwm-atmel-tcb.o
    > obj-$(CONFIG_PWM_BFIN) += pwm-bfin.o
    > obj-$(CONFIG_PWM_CLPS711X) += pwm-clps711x.o
    > diff --git a/drivers/pwm/pwm-atmel-hlcdc.c b/drivers/pwm/pwm-atmel-hlcdc.c
    > new file mode 100644
    > index 0000000..080e43e
    > --- /dev/null
    > +++ b/drivers/pwm/pwm-atmel-hlcdc.c
    > @@ -0,0 +1,216 @@
    > +/*
    > + * Copyright (C) 2014 Free Electrons
    > + * Copyright (C) 2014 Atmel
    > + *
    > + * Author: Boris BREZILLON <boris.brezillon@free-electrons.com>
    > + *
    > + * 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.
    > + *
    > + * This program is distributed in the hope that it will be useful, but WITHOUT
    > + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    > + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
    > + * more details.
    > + *
    > + * You should have received a copy of the GNU General Public License along with
    > + * this program. If not, see <http://www.gnu.org/licenses/>.
    > + */
    > +
    > +#include <linux/mfd/atmel-hlcdc.h>
    > +#include <linux/module.h>
    > +#include <linux/platform_device.h>
    > +#include <linux/pwm.h>
    > +
    > +#define ATMEL_HLCDC_PWMCVAL_MASK (0xff << 8)
    > +#define ATMEL_HLCDC_PWMCVAL(x) (((x) & 0xff) << 8)
    > +#define ATMEL_HLCDC_PWMPOL BIT(4)
    > +#define ATMEL_HLCDC_PWMPS_MASK 0x7
    > +#define ATMEL_HLCDC_PWMPS_MAX 0x6
    > +#define ATMEL_HLCDC_PWMPS(x) ((x) & 0x7)
    > +
    > +struct atmel_hlcdc_pwm_chip {
    > + struct pwm_chip chip;
    > + struct atmel_hlcdc *hlcdc;
    > + struct clk *cur_clk;
    > +};
    > +
    > +static inline struct atmel_hlcdc_pwm_chip *
    > +pwm_chip_to_atmel_hlcdc_pwm_chip(struct pwm_chip *chip)
    > +{
    > + return container_of(chip, struct atmel_hlcdc_pwm_chip, chip);
    > +}
    > +
    > +static int atmel_hlcdc_pwm_config(struct pwm_chip *c,
    > + struct pwm_device *pwm,
    > + int duty_ns, int period_ns)
    > +{
    > + struct atmel_hlcdc_pwm_chip *chip =
    > + pwm_chip_to_atmel_hlcdc_pwm_chip(c);
    > + struct atmel_hlcdc *hlcdc = chip->hlcdc;
    > + struct clk *new_clk = hlcdc->slow_clk;
    > + u64 pwmcval = duty_ns * 256;
    > + unsigned long clk_freq;
    > + u64 clk_period_ns;
    > + u32 pwmcfg;
    > + int pres;
    > +
    > + clk_freq = clk_get_rate(new_clk);
    > + clk_period_ns = 1000000000;
    > + clk_period_ns *= 256;
    > + do_div(clk_period_ns, clk_freq);
    > +
    > + if (clk_period_ns > period_ns) {
    > + new_clk = hlcdc->sys_clk;
    > + clk_freq = clk_get_rate(new_clk);
    > + clk_period_ns = 1000000000;
    > + clk_period_ns *= 256;
    > + do_div(clk_period_ns, clk_freq);
    > + }
    > +
    > + for (pres = ATMEL_HLCDC_PWMPS_MAX; pres >= 0; pres--) {
    > + if ((clk_period_ns << pres) <= period_ns)
    > + break;
    > + }
    > +
    > + if (pres > ATMEL_HLCDC_PWMPS_MAX)
    > + return -EINVAL;
    > +
    > + pwmcfg = ATMEL_HLCDC_PWMPS(pres);
    > +
    > + if (new_clk != chip->cur_clk) {
    > + u32 gencfg = 0;
    > +
    > + clk_prepare_enable(new_clk);
    > + clk_disable_unprepare(chip->cur_clk);
    > + chip->cur_clk = new_clk;
    > +
    > + if (new_clk != hlcdc->slow_clk)
    > + gencfg = ATMEL_HLCDC_CLKPWMSEL;
    > + regmap_update_bits(hlcdc->regmap, ATMEL_HLCDC_CFG(0),
    > + ATMEL_HLCDC_CLKPWMSEL, gencfg);
    > + }
    > +
    > + do_div(pwmcval, period_ns);
    > + if (pwmcval > 255)
    > + pwmcval = 255;
    > +
    > + pwmcfg |= ATMEL_HLCDC_PWMCVAL(pwmcval);
    > +
    > + regmap_update_bits(hlcdc->regmap, ATMEL_HLCDC_CFG(6),
    > + ATMEL_HLCDC_PWMCVAL_MASK | ATMEL_HLCDC_PWMPS_MASK,
    > + pwmcfg);
    > +
    > + return 0;
    > +}
    > +
    > +static int atmel_hlcdc_pwm_set_polarity(struct pwm_chip *c,
    > + struct pwm_device *pwm,
    > + enum pwm_polarity polarity)
    > +{
    > + struct atmel_hlcdc_pwm_chip *chip =
    > + pwm_chip_to_atmel_hlcdc_pwm_chip(c);
    > + struct atmel_hlcdc *hlcdc = chip->hlcdc;
    > + u32 cfg = 0;
    > +
    > + if (polarity == PWM_POLARITY_NORMAL)
    > + cfg = ATMEL_HLCDC_PWMPOL;
    > +
    > + regmap_update_bits(hlcdc->regmap, ATMEL_HLCDC_CFG(6),
    > + ATMEL_HLCDC_PWMPOL, cfg);
    > +
    > + return 0;
    > +}
    > +
    > +static int atmel_hlcdc_pwm_enable(struct pwm_chip *c,
    > + struct pwm_device *pwm)
    > +{
    > + struct atmel_hlcdc_pwm_chip *chip =
    > + pwm_chip_to_atmel_hlcdc_pwm_chip(c);
    > + struct atmel_hlcdc *hlcdc = chip->hlcdc;
    > + u32 status;
    > +
    > + regmap_write(hlcdc->regmap, ATMEL_HLCDC_EN, ATMEL_HLCDC_PWM);
    > + while (!regmap_read(hlcdc->regmap, ATMEL_HLCDC_SR, &status) &&
    > + !(status & ATMEL_HLCDC_PWM))
    > + cpu_relax();
    > +
    > + return 0;
    > +}
    > +
    > +static void atmel_hlcdc_pwm_disable(struct pwm_chip *c,
    > + struct pwm_device *pwm)
    > +{
    > + struct atmel_hlcdc_pwm_chip *chip =
    > + pwm_chip_to_atmel_hlcdc_pwm_chip(c);
    > + struct atmel_hlcdc *hlcdc = chip->hlcdc;
    > + u32 status;
    > +
    > + regmap_write(hlcdc->regmap, ATMEL_HLCDC_DIS, ATMEL_HLCDC_PWM);
    > + while (!regmap_read(hlcdc->regmap, ATMEL_HLCDC_SR, &status) &&
    > + (status & ATMEL_HLCDC_PWM))
    > + cpu_relax();
    > +}
    > +
    > +static const struct pwm_ops atmel_hlcdc_pwm_ops = {
    > + .config = atmel_hlcdc_pwm_config,
    > + .set_polarity = atmel_hlcdc_pwm_set_polarity,
    > + .enable = atmel_hlcdc_pwm_enable,
    > + .disable = atmel_hlcdc_pwm_disable,
    > + .owner = THIS_MODULE,
    > +};
    > +
    > +static int atmel_hlcdc_pwm_probe(struct platform_device *pdev)
    > +{
    > + struct atmel_hlcdc_pwm_chip *chip;
    > + struct device *dev = &pdev->dev;
    > + int ret;
    > +
    > + chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
    > + if (!chip)
    > + return -ENOMEM;
    > +
    > + chip->hlcdc = dev_get_drvdata(dev->parent);
    > + chip->chip.ops = &atmel_hlcdc_pwm_ops;
    > + chip->chip.dev = dev;
    > + chip->chip.base = -1;
    > + chip->chip.npwm = 1;
    > + chip->chip.of_xlate = of_pwm_xlate_with_flags;
    > + chip->chip.of_pwm_n_cells = 3;
    > + chip->chip.can_sleep = 1;
    > +
    > + ret = pwmchip_add(&chip->chip);
    > + if (ret)
    > + return ret;
    > +
    > + platform_set_drvdata(pdev, chip);
    > +
    > + return 0;
    > +}
    > +
    > +static int atmel_hlcdc_pwm_remove(struct platform_device *pdev)
    > +{
    > + struct atmel_hlcdc_pwm_chip *chip = platform_get_drvdata(pdev);
    > +
    > + return pwmchip_remove(&chip->chip);
    > +}
    > +
    > +static const struct of_device_id atmel_hlcdc_pwm_dt_ids[] = {
    > + { .compatible = "atmel,hlcdc-pwm" },
    > + { /* sentinel */ },
    > +};
    > +
    > +static struct platform_driver atmel_hlcdc_pwm_driver = {
    > + .driver = {
    > + .name = "atmel-hlcdc-pwm",
    > + .of_match_table = atmel_hlcdc_pwm_dt_ids,
    > + },
    > + .probe = atmel_hlcdc_pwm_probe,
    > + .remove = atmel_hlcdc_pwm_remove,
    > +};
    > +module_platform_driver(atmel_hlcdc_pwm_driver);
    > +
    > +MODULE_ALIAS("platform:atmel-hlcdc-pwm");
    > +MODULE_AUTHOR("Boris Brezillon <boris.brezillon@free-electrons.com>");
    > +MODULE_DESCRIPTION("Atmel HLCDC PWM driver");
    > +MODULE_LICENSE("GPL");
    >


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