* [PATCH v9 0/2] pwm: add support for atmel-hlcdc-pwm device
@ 2014-10-07 10:14 Boris Brezillon
2014-10-07 10:14 ` [PATCH v9 1/2] " Boris Brezillon
2014-10-07 10:14 ` [PATCH v9 2/2] pwm: add DT bindings documentation for atmel-hlcdc-pwm driver Boris Brezillon
0 siblings, 2 replies; 5+ messages in thread
From: Boris Brezillon @ 2014-10-07 10:14 UTC (permalink / raw)
To: linux-arm-kernel
Hi Thierry,
This patch series adds support for the atmel-hlcdc-pwm device provided
by the atmel-hlcdc MFD driver.
It depends on this series [1] implementing the MFD driver.
Best Regards,
Boris
[1]http://www.mail-archive.com/devicetree at vger.kernel.org/msg44979.html
Changes since v8:
- rework the enable/disable waiting loop
- check return code of regmap functions
- fix DT binding doc
Changes since v7:
- addressed several coding style issues
Boris Brezillon (2):
pwm: add support for atmel-hlcdc-pwm device
pwm: add DT bindings documentation for atmel-hlcdc-pwm driver
.../devicetree/bindings/pwm/atmel-hlcdc-pwm.txt | 29 +++
drivers/pwm/Kconfig | 9 +
drivers/pwm/Makefile | 1 +
drivers/pwm/pwm-atmel-hlcdc.c | 259 +++++++++++++++++++++
4 files changed, 298 insertions(+)
create mode 100644 Documentation/devicetree/bindings/pwm/atmel-hlcdc-pwm.txt
create mode 100644 drivers/pwm/pwm-atmel-hlcdc.c
--
1.9.1
^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH v9 1/2] pwm: add support for atmel-hlcdc-pwm device
2014-10-07 10:14 [PATCH v9 0/2] pwm: add support for atmel-hlcdc-pwm device Boris Brezillon
@ 2014-10-07 10:14 ` Boris Brezillon
2014-10-07 12:45 ` Nicolas Ferre
2014-10-07 10:14 ` [PATCH v9 2/2] pwm: add DT bindings documentation for atmel-hlcdc-pwm driver Boris Brezillon
1 sibling, 1 reply; 5+ messages in thread
From: Boris Brezillon @ 2014-10-07 10:14 UTC (permalink / raw)
To: linux-arm-kernel
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 a PWM chip exposing a single PWM device (which
will most likely be used to drive a backlight device).
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Tested-by: Anthony Harivel <anthony.harivel@emtrion.de>
Tested-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Acked-by: Thierry Reding <thierry.reding@gmail.com>
---
drivers/pwm/Kconfig | 9 ++
drivers/pwm/Makefile | 1 +
drivers/pwm/pwm-atmel-hlcdc.c | 259 ++++++++++++++++++++++++++++++++++++++++++
3 files changed, 269 insertions(+)
create mode 100644 drivers/pwm/pwm-atmel-hlcdc.c
diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index b800783..c36f308 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"
+ select MFD_ATMEL_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-hlcdc.
+
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 f8c577d..eb0aae5 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-$(CONFIG_PWM_BCM_KONA) += pwm-bcm-kona.o
obj-$(CONFIG_PWM_BFIN) += pwm-bfin.o
diff --git a/drivers/pwm/pwm-atmel-hlcdc.c b/drivers/pwm/pwm-atmel-hlcdc.c
new file mode 100644
index 0000000..eaf8b12
--- /dev/null
+++ b/drivers/pwm/pwm-atmel-hlcdc.c
@@ -0,0 +1,259 @@
+/*
+ * 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/clk.h>
+#include <linux/delay.h>
+#include <linux/mfd/atmel-hlcdc.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+#include <linux/regmap.h>
+
+#define ATMEL_HLCDC_PWMCVAL_MASK GENMASK(15, 8)
+#define ATMEL_HLCDC_PWMCVAL(x) (((x) << 8) & ATMEL_HLCDC_PWMCVAL_MASK)
+#define ATMEL_HLCDC_PWMPOL BIT(4)
+#define ATMEL_HLCDC_PWMPS_MASK GENMASK(2, 0)
+#define ATMEL_HLCDC_PWMPS_MAX 0x6
+#define ATMEL_HLCDC_PWMPS(x) ((x) & ATMEL_HLCDC_PWMPS_MASK)
+
+struct atmel_hlcdc_pwm {
+ struct pwm_chip chip;
+ struct atmel_hlcdc *hlcdc;
+ struct clk *cur_clk;
+};
+
+static inline struct atmel_hlcdc_pwm *to_atmel_hlcdc_pwm(struct pwm_chip *chip)
+{
+ return container_of(chip, struct atmel_hlcdc_pwm, 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 = to_atmel_hlcdc_pwm(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 = (u64)NSEC_PER_SEC * 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 = (u64)NSEC_PER_SEC * 256;
+ do_div(clk_period_ns, clk_freq);
+ }
+
+ for (pres = 0; pres <= ATMEL_HLCDC_PWMPS_MAX; 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;
+ int ret;
+
+ ret = clk_prepare_enable(new_clk);
+ if (ret)
+ return ret;
+
+ clk_disable_unprepare(chip->cur_clk);
+ chip->cur_clk = new_clk;
+
+ if (new_clk == hlcdc->sys_clk)
+ gencfg = ATMEL_HLCDC_CLKPWMSEL;
+
+ ret = regmap_update_bits(hlcdc->regmap, ATMEL_HLCDC_CFG(0),
+ ATMEL_HLCDC_CLKPWMSEL, gencfg);
+ if (ret)
+ return ret;
+ }
+
+ do_div(pwmcval, period_ns);
+
+ /*
+ * The PWM duty cycle is configurable from 0/256 to 255/256 of the
+ * period cycle. Hence we can't set a duty cycle occupying the
+ * whole period cycle if we're asked to.
+ * Set it to 255 if pwmcval is greater than 256.
+ */
+ if (pwmcval > 255)
+ pwmcval = 255;
+
+ pwmcfg |= ATMEL_HLCDC_PWMCVAL(pwmcval);
+
+ return regmap_update_bits(hlcdc->regmap, ATMEL_HLCDC_CFG(6),
+ ATMEL_HLCDC_PWMCVAL_MASK |
+ ATMEL_HLCDC_PWMPS_MASK,
+ pwmcfg);
+}
+
+static int atmel_hlcdc_pwm_set_polarity(struct pwm_chip *c,
+ struct pwm_device *pwm,
+ enum pwm_polarity polarity)
+{
+ struct atmel_hlcdc_pwm *chip = to_atmel_hlcdc_pwm(c);
+ struct atmel_hlcdc *hlcdc = chip->hlcdc;
+ u32 cfg = 0;
+
+ if (polarity == PWM_POLARITY_NORMAL)
+ cfg = ATMEL_HLCDC_PWMPOL;
+
+ return regmap_update_bits(hlcdc->regmap, ATMEL_HLCDC_CFG(6),
+ ATMEL_HLCDC_PWMPOL, cfg);
+}
+
+static int atmel_hlcdc_pwm_enable(struct pwm_chip *c, struct pwm_device *pwm)
+{
+ struct atmel_hlcdc_pwm *chip = to_atmel_hlcdc_pwm(c);
+ struct atmel_hlcdc *hlcdc = chip->hlcdc;
+ u32 status;
+ int ret;
+
+ ret = regmap_write(hlcdc->regmap, ATMEL_HLCDC_EN, ATMEL_HLCDC_PWM);
+ if (ret)
+ return ret;
+
+ while (true) {
+ ret = regmap_read(hlcdc->regmap, ATMEL_HLCDC_SR, &status);
+ if (ret)
+ return ret;
+
+ if ((status & ATMEL_HLCDC_PWM) != 0)
+ break;
+
+ usleep_range(1, 10);
+ }
+
+ return 0;
+}
+
+static void atmel_hlcdc_pwm_disable(struct pwm_chip *c,
+ struct pwm_device *pwm)
+{
+ struct atmel_hlcdc_pwm *chip = to_atmel_hlcdc_pwm(c);
+ struct atmel_hlcdc *hlcdc = chip->hlcdc;
+ u32 status;
+ int ret;
+
+ ret = regmap_write(hlcdc->regmap, ATMEL_HLCDC_DIS, ATMEL_HLCDC_PWM);
+ if (ret)
+ return;
+
+ while (true) {
+ ret = regmap_read(hlcdc->regmap, ATMEL_HLCDC_SR, &status);
+ if (ret)
+ return;
+
+ if ((status & ATMEL_HLCDC_PWM) == 0)
+ break;
+
+ usleep_range(1, 10);
+ }
+}
+
+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 device *dev = &pdev->dev;
+ struct atmel_hlcdc_pwm *chip;
+ struct atmel_hlcdc *hlcdc;
+ int ret;
+
+ hlcdc = dev_get_drvdata(dev->parent);
+
+ chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
+ if (!chip)
+ return -ENOMEM;
+
+ ret = clk_prepare_enable(hlcdc->periph_clk);
+ if (ret)
+ return ret;
+
+ chip->hlcdc = hlcdc;
+ 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) {
+ clk_disable_unprepare(hlcdc->periph_clk);
+ return ret;
+ }
+
+ platform_set_drvdata(pdev, chip);
+
+ return 0;
+}
+
+static int atmel_hlcdc_pwm_remove(struct platform_device *pdev)
+{
+ struct atmel_hlcdc_pwm *chip = platform_get_drvdata(pdev);
+ int ret;
+
+ ret = pwmchip_remove(&chip->chip);
+ if (ret)
+ return ret;
+
+ clk_disable_unprepare(chip->hlcdc->periph_clk);
+
+ return 0;
+}
+
+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 v2");
--
1.9.1
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH v9 2/2] pwm: add DT bindings documentation for atmel-hlcdc-pwm driver
2014-10-07 10:14 [PATCH v9 0/2] pwm: add support for atmel-hlcdc-pwm device Boris Brezillon
2014-10-07 10:14 ` [PATCH v9 1/2] " Boris Brezillon
@ 2014-10-07 10:14 ` Boris Brezillon
2014-10-07 12:55 ` Nicolas Ferre
1 sibling, 1 reply; 5+ messages in thread
From: Boris Brezillon @ 2014-10-07 10:14 UTC (permalink / raw)
To: linux-arm-kernel
The HLCDC IP available in some Atmel SoCs (i.e. sam9x5i.e. at91sam9n12,
at91sam9x5 family or sama5d3 family) provide a PWM device.
The DT bindings used for this PWM device is following the default 3 cells
bindings described in Documentation/devicetree/bindings/pwm/pwm.txt.
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
---
.../devicetree/bindings/pwm/atmel-hlcdc-pwm.txt | 29 ++++++++++++++++++++++
1 file changed, 29 insertions(+)
create mode 100644 Documentation/devicetree/bindings/pwm/atmel-hlcdc-pwm.txt
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..8a85244
--- /dev/null
+++ b/Documentation/devicetree/bindings/pwm/atmel-hlcdc-pwm.txt
@@ -0,0 +1,29 @@
+Device-Tree bindings for Atmel's HLCDC (High LCD Controller) PWM driver
+
+The Atmel HLCDC PWM is subdevice of the HLCDC MFD device.
+See ../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. This PWM chip use the default 3 cells
+ bindings defined in pwm.txt in this directory.
+
+Example:
+
+ hlcdc: hlcdc at f0030000 {
+ compatible = "atmel,sama5d3-hlcdc";
+ reg = <0xf0030000 0x2000>;
+ clocks = <&lcdc_clk>, <&lcdck>, <&clk32k>;
+ clock-names = "periph_clk","sys_clk", "slow_clk";
+
+ hlcdc_pwm: hlcdc-pwm {
+ compatible = "atmel,hlcdc-pwm";
+ pinctrl-names = "default";
+ pinctrl-0 = <&pinctrl_lcd_pwm>;
+ #pwm-cells = <3>;
+ };
+ };
--
1.9.1
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH v9 1/2] pwm: add support for atmel-hlcdc-pwm device
2014-10-07 10:14 ` [PATCH v9 1/2] " Boris Brezillon
@ 2014-10-07 12:45 ` Nicolas Ferre
0 siblings, 0 replies; 5+ messages in thread
From: Nicolas Ferre @ 2014-10-07 12:45 UTC (permalink / raw)
To: linux-arm-kernel
On 07/10/2014 12:14, Boris Brezillon :
> The HLCDC IP available in some Atmel SoCs (i.e. sam9x5i.e. at91sam9n12,
What is this sam9x5i.e. ? I would say instead:
The HLCDC IP available in some Atmel SoCs (i.e. at91sam9x5, at91sam9n12
or sama5d3 families for instance) provides a PWM device.
> at91sam9x5 family or sama5d3 family) provide a PWM device.
>
> This driver add support for a PWM chip exposing a single PWM device (which
> will most likely be used to drive a backlight device).
>
> Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
> Tested-by: Anthony Harivel <anthony.harivel@emtrion.de>
> Tested-by: Ludovic Desroches <ludovic.desroches@atmel.com>
> Acked-by: Thierry Reding <thierry.reding@gmail.com>
See the little nitpicking...
But otherwise:
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
> ---
> drivers/pwm/Kconfig | 9 ++
> drivers/pwm/Makefile | 1 +
> drivers/pwm/pwm-atmel-hlcdc.c | 259 ++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 269 insertions(+)
> create mode 100644 drivers/pwm/pwm-atmel-hlcdc.c
>
> diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
> index b800783..c36f308 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"
> + select MFD_ATMEL_HLCDC
> + help
> + Generic PWM framework driver for Atmel HLCDC PWM.
What about:
"Generic PWM framework driver for the PWM output of the HLCDC (Atmel
High-end LCD Controller). This PWM output is mainly used to control the
LCD backlight.
> +
> + To compile this driver as a module, choose M here: the module
> + will be called pwm-atmel-hlcdc.
> +
> 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 f8c577d..eb0aae5 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-$(CONFIG_PWM_BCM_KONA) += pwm-bcm-kona.o
> obj-$(CONFIG_PWM_BFIN) += pwm-bfin.o
> diff --git a/drivers/pwm/pwm-atmel-hlcdc.c b/drivers/pwm/pwm-atmel-hlcdc.c
> new file mode 100644
> index 0000000..eaf8b12
> --- /dev/null
> +++ b/drivers/pwm/pwm-atmel-hlcdc.c
> @@ -0,0 +1,259 @@
> +/*
> + * 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/clk.h>
> +#include <linux/delay.h>
> +#include <linux/mfd/atmel-hlcdc.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/pwm.h>
> +#include <linux/regmap.h>
> +
> +#define ATMEL_HLCDC_PWMCVAL_MASK GENMASK(15, 8)
> +#define ATMEL_HLCDC_PWMCVAL(x) (((x) << 8) & ATMEL_HLCDC_PWMCVAL_MASK)
> +#define ATMEL_HLCDC_PWMPOL BIT(4)
> +#define ATMEL_HLCDC_PWMPS_MASK GENMASK(2, 0)
> +#define ATMEL_HLCDC_PWMPS_MAX 0x6
> +#define ATMEL_HLCDC_PWMPS(x) ((x) & ATMEL_HLCDC_PWMPS_MASK)
> +
> +struct atmel_hlcdc_pwm {
> + struct pwm_chip chip;
> + struct atmel_hlcdc *hlcdc;
> + struct clk *cur_clk;
> +};
> +
> +static inline struct atmel_hlcdc_pwm *to_atmel_hlcdc_pwm(struct pwm_chip *chip)
> +{
> + return container_of(chip, struct atmel_hlcdc_pwm, 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 = to_atmel_hlcdc_pwm(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 = (u64)NSEC_PER_SEC * 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 = (u64)NSEC_PER_SEC * 256;
> + do_div(clk_period_ns, clk_freq);
> + }
> +
> + for (pres = 0; pres <= ATMEL_HLCDC_PWMPS_MAX; 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;
> + int ret;
> +
> + ret = clk_prepare_enable(new_clk);
> + if (ret)
> + return ret;
> +
> + clk_disable_unprepare(chip->cur_clk);
> + chip->cur_clk = new_clk;
> +
> + if (new_clk == hlcdc->sys_clk)
> + gencfg = ATMEL_HLCDC_CLKPWMSEL;
> +
> + ret = regmap_update_bits(hlcdc->regmap, ATMEL_HLCDC_CFG(0),
> + ATMEL_HLCDC_CLKPWMSEL, gencfg);
> + if (ret)
> + return ret;
> + }
> +
> + do_div(pwmcval, period_ns);
> +
> + /*
> + * The PWM duty cycle is configurable from 0/256 to 255/256 of the
> + * period cycle. Hence we can't set a duty cycle occupying the
> + * whole period cycle if we're asked to.
> + * Set it to 255 if pwmcval is greater than 256.
> + */
> + if (pwmcval > 255)
> + pwmcval = 255;
> +
> + pwmcfg |= ATMEL_HLCDC_PWMCVAL(pwmcval);
> +
> + return regmap_update_bits(hlcdc->regmap, ATMEL_HLCDC_CFG(6),
> + ATMEL_HLCDC_PWMCVAL_MASK |
> + ATMEL_HLCDC_PWMPS_MASK,
> + pwmcfg);
> +}
> +
> +static int atmel_hlcdc_pwm_set_polarity(struct pwm_chip *c,
> + struct pwm_device *pwm,
> + enum pwm_polarity polarity)
> +{
> + struct atmel_hlcdc_pwm *chip = to_atmel_hlcdc_pwm(c);
> + struct atmel_hlcdc *hlcdc = chip->hlcdc;
> + u32 cfg = 0;
> +
> + if (polarity == PWM_POLARITY_NORMAL)
> + cfg = ATMEL_HLCDC_PWMPOL;
> +
> + return regmap_update_bits(hlcdc->regmap, ATMEL_HLCDC_CFG(6),
> + ATMEL_HLCDC_PWMPOL, cfg);
> +}
> +
> +static int atmel_hlcdc_pwm_enable(struct pwm_chip *c, struct pwm_device *pwm)
> +{
> + struct atmel_hlcdc_pwm *chip = to_atmel_hlcdc_pwm(c);
> + struct atmel_hlcdc *hlcdc = chip->hlcdc;
> + u32 status;
> + int ret;
> +
> + ret = regmap_write(hlcdc->regmap, ATMEL_HLCDC_EN, ATMEL_HLCDC_PWM);
> + if (ret)
> + return ret;
> +
> + while (true) {
> + ret = regmap_read(hlcdc->regmap, ATMEL_HLCDC_SR, &status);
> + if (ret)
> + return ret;
> +
> + if ((status & ATMEL_HLCDC_PWM) != 0)
> + break;
> +
> + usleep_range(1, 10);
> + }
> +
> + return 0;
> +}
> +
> +static void atmel_hlcdc_pwm_disable(struct pwm_chip *c,
> + struct pwm_device *pwm)
> +{
> + struct atmel_hlcdc_pwm *chip = to_atmel_hlcdc_pwm(c);
> + struct atmel_hlcdc *hlcdc = chip->hlcdc;
> + u32 status;
> + int ret;
> +
> + ret = regmap_write(hlcdc->regmap, ATMEL_HLCDC_DIS, ATMEL_HLCDC_PWM);
> + if (ret)
> + return;
> +
> + while (true) {
> + ret = regmap_read(hlcdc->regmap, ATMEL_HLCDC_SR, &status);
> + if (ret)
> + return;
> +
> + if ((status & ATMEL_HLCDC_PWM) == 0)
> + break;
> +
> + usleep_range(1, 10);
> + }
> +}
> +
> +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 device *dev = &pdev->dev;
> + struct atmel_hlcdc_pwm *chip;
> + struct atmel_hlcdc *hlcdc;
> + int ret;
> +
> + hlcdc = dev_get_drvdata(dev->parent);
> +
> + chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
> + if (!chip)
> + return -ENOMEM;
> +
> + ret = clk_prepare_enable(hlcdc->periph_clk);
> + if (ret)
> + return ret;
> +
> + chip->hlcdc = hlcdc;
> + 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) {
> + clk_disable_unprepare(hlcdc->periph_clk);
> + return ret;
> + }
> +
> + platform_set_drvdata(pdev, chip);
> +
> + return 0;
> +}
> +
> +static int atmel_hlcdc_pwm_remove(struct platform_device *pdev)
> +{
> + struct atmel_hlcdc_pwm *chip = platform_get_drvdata(pdev);
> + int ret;
> +
> + ret = pwmchip_remove(&chip->chip);
> + if (ret)
> + return ret;
> +
> + clk_disable_unprepare(chip->hlcdc->periph_clk);
> +
> + return 0;
> +}
> +
> +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 v2");
>
--
Nicolas Ferre
^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH v9 2/2] pwm: add DT bindings documentation for atmel-hlcdc-pwm driver
2014-10-07 10:14 ` [PATCH v9 2/2] pwm: add DT bindings documentation for atmel-hlcdc-pwm driver Boris Brezillon
@ 2014-10-07 12:55 ` Nicolas Ferre
0 siblings, 0 replies; 5+ messages in thread
From: Nicolas Ferre @ 2014-10-07 12:55 UTC (permalink / raw)
To: linux-arm-kernel
On 07/10/2014 12:14, Boris Brezillon :
> The HLCDC IP available in some Atmel SoCs (i.e. sam9x5i.e. at91sam9n12,
Ditto: sam9x5 doesn't exist.
> at91sam9x5 family or sama5d3 family) provide a PWM device.
>
> The DT bindings used for this PWM device is following the default 3 cells
> bindings described in Documentation/devicetree/bindings/pwm/pwm.txt.
>
> Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
> ---
> .../devicetree/bindings/pwm/atmel-hlcdc-pwm.txt | 29 ++++++++++++++++++++++
> 1 file changed, 29 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/pwm/atmel-hlcdc-pwm.txt
>
> 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..8a85244
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/pwm/atmel-hlcdc-pwm.txt
> @@ -0,0 +1,29 @@
> +Device-Tree bindings for Atmel's HLCDC (High LCD Controller) PWM driver
s/High/High-end/
> +
> +The Atmel HLCDC PWM is subdevice of the HLCDC MFD device.
> +See ../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. This PWM chip use the default 3 cells
> + bindings defined in pwm.txt in this directory.
> +
> +Example:
> +
> + hlcdc: hlcdc at f0030000 {
> + compatible = "atmel,sama5d3-hlcdc";
> + reg = <0xf0030000 0x2000>;
> + clocks = <&lcdc_clk>, <&lcdck>, <&clk32k>;
> + clock-names = "periph_clk","sys_clk", "slow_clk";
> +
> + hlcdc_pwm: hlcdc-pwm {
> +
> + pinctrl-names = "default";
> + pinctrl-0 = <&pinctrl_lcd_pwm>;
> + #pwm-cells = <3>;
> + };
> + };
>
otherwise,
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Thanks.
--
Nicolas Ferre
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2014-10-07 12:55 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2014-10-07 10:14 [PATCH v9 0/2] pwm: add support for atmel-hlcdc-pwm device Boris Brezillon
2014-10-07 10:14 ` [PATCH v9 1/2] " Boris Brezillon
2014-10-07 12:45 ` Nicolas Ferre
2014-10-07 10:14 ` [PATCH v9 2/2] pwm: add DT bindings documentation for atmel-hlcdc-pwm driver Boris Brezillon
2014-10-07 12:55 ` Nicolas Ferre
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