Re: [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");