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

Boris BREZILLON
2014-06-09T16:04:40Z

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
+ 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");
--
1.8.3.2