| Message ID | 1440576450-17420-2-git-send-email-antoine.tenart@free-electrons.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Antoine, Just one observation below. El 26/08/15 a las 05:07, Antoine Tenart escribió: > Add a PWM controller driver for the Marvell Berlin SoCs. This PWM > controller has 4 channels. > > Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com> > Acked-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com> > --- > drivers/pwm/Kconfig | 9 ++ > drivers/pwm/Makefile | 1 + > drivers/pwm/pwm-berlin.c | 227 +++++++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 237 insertions(+) > create mode 100644 drivers/pwm/pwm-berlin.c > > diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig > index b1541f40fd8d..1773da8145b8 100644 > --- a/drivers/pwm/Kconfig > +++ b/drivers/pwm/Kconfig > @@ -92,6 +92,15 @@ config PWM_BCM2835 > To compile this driver as a module, choose M here: the module > will be called pwm-bcm2835. > > +config PWM_BERLIN > + tristate "Berlin PWM support" > + depends on ARCH_BERLIN > + help > + PWM framework driver for Berlin. > + > + To compile this driver as a module, choose M here: the module > + will be called pwm-berlin. > + > config PWM_BFIN > tristate "Blackfin PWM support" > depends on BFIN_GPTIMERS > diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile > index ec50eb5b5a8f..670c5fce8bbb 100644 > --- a/drivers/pwm/Makefile > +++ b/drivers/pwm/Makefile > @@ -6,6 +6,7 @@ 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_BCM2835) += pwm-bcm2835.o > +obj-$(CONFIG_PWM_BERLIN) += pwm-berlin.o > obj-$(CONFIG_PWM_BFIN) += pwm-bfin.o > obj-$(CONFIG_PWM_CLPS711X) += pwm-clps711x.o > obj-$(CONFIG_PWM_EP93XX) += pwm-ep93xx.o > diff --git a/drivers/pwm/pwm-berlin.c b/drivers/pwm/pwm-berlin.c > new file mode 100644 > index 000000000000..3a373fd72892 > --- /dev/null > +++ b/drivers/pwm/pwm-berlin.c > @@ -0,0 +1,227 @@ > +/* > + * Marvell Berlin PWM driver > + * > + * Copyright (C) 2015 Marvell Technology Group Ltd. > + * > + * Antoine Tenart <antoine.tenart@free-electrons.com> > + * > + * This file is licensed under the terms of the GNU General Public > + * License version 2. This program is licensed "as is" without any > + * warranty of any kind, whether express or implied. > + */ > + > +#include <linux/clk.h> > +#include <linux/io.h> > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/platform_device.h> > +#include <linux/pwm.h> > +#include <linux/spinlock.h> > + > +#define BERLIN_PWM_EN 0x0 > +#define BERLIN_PWM_CONTROL 0x4 > +#define BERLIN_PWM_DUTY 0x8 > +#define BERLIN_PWM_TCNT 0xc > + > +#define BERLIN_PWM_ENABLE BIT(0) > +#define BERLIN_PWM_INVERT_POLARITY BIT(3) > +#define BERLIN_PWM_PRESCALE_MASK 0x7 > +#define BERLIN_PWM_PRESCALE_MAX 4096 > +#define BERLIN_PWM_MAX_TCNT 65535 > + > +struct berlin_pwm_chip { > + struct pwm_chip chip; > + struct clk *clk; > + void __iomem *base; > + spinlock_t lock; > +}; > + > +#define to_berlin_pwm_chip(chip) \ > + container_of((chip), struct berlin_pwm_chip, chip) > + > +#define berlin_pwm_readl(chip, channel, offset) \ > + readl_relaxed((chip)->base + (channel) * 0x10 + offset) > +#define berlin_pwm_writel(val, chip, channel, offset) \ > + writel_relaxed(val, (chip)->base + (channel) * 0x10 + offset) > + > +/* prescaler table: {1, 4, 8, 16, 64, 256, 1024, 4096} */ > +static const u32 prescaler_diff_table[] = { > + 1, 4, 2, 2, 4, 4, 4, 4, > +}; > + > +static int berlin_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm_dev, > + int duty_ns, int period_ns) > +{ > + struct berlin_pwm_chip *pwm = to_berlin_pwm_chip(chip); > + int prescale = 0; > + u32 val, duty, period; > + u64 cycles; > + > + cycles = clk_get_rate(pwm->clk); > + cycles *= period_ns; > + do_div(cycles, NSEC_PER_SEC); > + > + while (cycles > BERLIN_PWM_MAX_TCNT) > + do_div(cycles, prescaler_diff_table[++prescale]); > + > + if (cycles > BERLIN_PWM_MAX_TCNT) > + return -EINVAL; > + > + period = cycles; > + cycles *= duty_ns; > + do_div(cycles, period_ns); > + duty = cycles; > + > + spin_lock(&pwm->lock); > + > + val = berlin_pwm_readl(pwm, pwm_dev->hwpwm, BERLIN_PWM_CONTROL); > + val &= ~BERLIN_PWM_PRESCALE_MASK; > + val |= prescale; > + berlin_pwm_writel(val, pwm, pwm_dev->hwpwm, BERLIN_PWM_CONTROL); > + > + berlin_pwm_writel(duty, pwm, pwm_dev->hwpwm, BERLIN_PWM_DUTY); > + berlin_pwm_writel(period, pwm, pwm_dev->hwpwm, BERLIN_PWM_TCNT); > + > + spin_unlock(&pwm->lock); > + > + return 0; > +} > + > +static int berlin_pwm_set_polarity(struct pwm_chip *chip, > + struct pwm_device *pwm_dev, > + enum pwm_polarity polarity) > +{ > + struct berlin_pwm_chip *pwm = to_berlin_pwm_chip(chip); > + u32 val; > + > + spin_lock(&pwm->lock); > + > + val = berlin_pwm_readl(pwm, pwm_dev->hwpwm, BERLIN_PWM_CONTROL); > + > + if (polarity == PWM_POLARITY_NORMAL) > + val &= ~BERLIN_PWM_INVERT_POLARITY; > + else > + val |= BERLIN_PWM_INVERT_POLARITY; > + > + berlin_pwm_writel(val, pwm, pwm_dev->hwpwm, BERLIN_PWM_CONTROL); > + > + spin_unlock(&pwm->lock); > + > + return 0; > +} > + > +static int berlin_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm_dev) > +{ > + struct berlin_pwm_chip *pwm = to_berlin_pwm_chip(chip); > + u32 val; > + > + spin_lock(&pwm->lock); > + > + val = berlin_pwm_readl(pwm, pwm_dev->hwpwm, BERLIN_PWM_EN); > + val |= BERLIN_PWM_ENABLE; > + berlin_pwm_writel(val, pwm, pwm_dev->hwpwm, BERLIN_PWM_EN); > + > + spin_unlock(&pwm->lock); > + > + return 0; > +} > + > +static void berlin_pwm_disable(struct pwm_chip *chip, > + struct pwm_device *pwm_dev) > +{ > + struct berlin_pwm_chip *pwm = to_berlin_pwm_chip(chip); > + u32 val; > + > + spin_lock(&pwm->lock); > + > + val = berlin_pwm_readl(pwm, pwm_dev->hwpwm, BERLIN_PWM_EN); > + val &= ~BERLIN_PWM_ENABLE; > + berlin_pwm_writel(val, pwm, pwm_dev->hwpwm, BERLIN_PWM_EN); > + > + spin_unlock(&pwm->lock); > +} > + > +static const struct pwm_ops berlin_pwm_ops = { > + .config = berlin_pwm_config, > + .set_polarity = berlin_pwm_set_polarity, > + .enable = berlin_pwm_enable, > + .disable = berlin_pwm_disable, > + .owner = THIS_MODULE, > +}; > + > +static const struct of_device_id berlin_pwm_match[] = { > + { .compatible = "marvell,berlin-pwm" }, > + { }, > +}; > +MODULE_DEVICE_TABLE(of, berlin_pwm_match); > + > +static int berlin_pwm_probe(struct platform_device *pdev) > +{ > + struct berlin_pwm_chip *pwm; > + struct resource *res; > + int ret; > + > + pwm = devm_kzalloc(&pdev->dev, sizeof(*pwm), GFP_KERNEL); > + if (!pwm) > + return -ENOMEM; > + > + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > + pwm->base = devm_ioremap_resource(&pdev->dev, res); > + if (IS_ERR(pwm->base)) > + return PTR_ERR(pwm->base); > + > + pwm->clk = devm_clk_get(&pdev->dev, NULL); > + if (IS_ERR(pwm->clk)) > + return PTR_ERR(pwm->clk); > + > + ret = clk_prepare_enable(pwm->clk); > + if (ret) > + return ret; > + > + pwm->chip.dev = &pdev->dev; > + pwm->chip.ops = &berlin_pwm_ops; > + pwm->chip.base = -1; > + pwm->chip.npwm = 4; > + pwm->chip.can_sleep = true; > + pwm->chip.of_xlate = of_pwm_xlate_with_flags; > + pwm->chip.of_pwm_n_cells = 3; > + > + spin_lock_init(&pwm->lock); > + > + ret = pwmchip_add(&pwm->chip); > + if (ret < 0) { > + dev_err(&pdev->dev, "Failed to add PWM chip: %d\n", ret); > + return ret; I think you're missing some cleanup routine here. You have a previous call to clk_prepare_enable(), so you may have a call to clk_disable_unprepare() here in order to exit cleanly, don't you think? > + } > + > + platform_set_drvdata(pdev, pwm); > + > + return 0; > +} > + > +static int berlin_pwm_remove(struct platform_device *pdev) > +{ > + struct berlin_pwm_chip *pwm = platform_get_drvdata(pdev); > + int ret; > + > + ret = pwmchip_remove(&pwm->chip); > + if (ret) > + return ret; > + > + clk_disable_unprepare(pwm->clk); > + return 0; > +} > + > +static struct platform_driver berlin_pwm_driver = { > + .probe = berlin_pwm_probe, > + .remove = berlin_pwm_remove, > + .driver = { > + .name = "berlin-pwm", > + .of_match_table = berlin_pwm_match, > + }, > +}; > +module_platform_driver(berlin_pwm_driver); > + > +MODULE_AUTHOR("Antoine Tenart <antoine.tenart@free-electrons.com>"); > +MODULE_DESCRIPTION("Marvell Berlin PWM driver"); > +MODULE_LICENSE("GPL v2"); >
diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig index b1541f40fd8d..1773da8145b8 100644 --- a/drivers/pwm/Kconfig +++ b/drivers/pwm/Kconfig @@ -92,6 +92,15 @@ config PWM_BCM2835 To compile this driver as a module, choose M here: the module will be called pwm-bcm2835. +config PWM_BERLIN + tristate "Berlin PWM support" + depends on ARCH_BERLIN + help + PWM framework driver for Berlin. + + To compile this driver as a module, choose M here: the module + will be called pwm-berlin. + config PWM_BFIN tristate "Blackfin PWM support" depends on BFIN_GPTIMERS diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile index ec50eb5b5a8f..670c5fce8bbb 100644 --- a/drivers/pwm/Makefile +++ b/drivers/pwm/Makefile @@ -6,6 +6,7 @@ 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_BCM2835) += pwm-bcm2835.o +obj-$(CONFIG_PWM_BERLIN) += pwm-berlin.o obj-$(CONFIG_PWM_BFIN) += pwm-bfin.o obj-$(CONFIG_PWM_CLPS711X) += pwm-clps711x.o obj-$(CONFIG_PWM_EP93XX) += pwm-ep93xx.o diff --git a/drivers/pwm/pwm-berlin.c b/drivers/pwm/pwm-berlin.c new file mode 100644 index 000000000000..3a373fd72892 --- /dev/null +++ b/drivers/pwm/pwm-berlin.c @@ -0,0 +1,227 @@ +/* + * Marvell Berlin PWM driver + * + * Copyright (C) 2015 Marvell Technology Group Ltd. + * + * Antoine Tenart <antoine.tenart@free-electrons.com> + * + * This file is licensed under the terms of the GNU General Public + * License version 2. This program is licensed "as is" without any + * warranty of any kind, whether express or implied. + */ + +#include <linux/clk.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/pwm.h> +#include <linux/spinlock.h> + +#define BERLIN_PWM_EN 0x0 +#define BERLIN_PWM_CONTROL 0x4 +#define BERLIN_PWM_DUTY 0x8 +#define BERLIN_PWM_TCNT 0xc + +#define BERLIN_PWM_ENABLE BIT(0) +#define BERLIN_PWM_INVERT_POLARITY BIT(3) +#define BERLIN_PWM_PRESCALE_MASK 0x7 +#define BERLIN_PWM_PRESCALE_MAX 4096 +#define BERLIN_PWM_MAX_TCNT 65535 + +struct berlin_pwm_chip { + struct pwm_chip chip; + struct clk *clk; + void __iomem *base; + spinlock_t lock; +}; + +#define to_berlin_pwm_chip(chip) \ + container_of((chip), struct berlin_pwm_chip, chip) + +#define berlin_pwm_readl(chip, channel, offset) \ + readl_relaxed((chip)->base + (channel) * 0x10 + offset) +#define berlin_pwm_writel(val, chip, channel, offset) \ + writel_relaxed(val, (chip)->base + (channel) * 0x10 + offset) + +/* prescaler table: {1, 4, 8, 16, 64, 256, 1024, 4096} */ +static const u32 prescaler_diff_table[] = { + 1, 4, 2, 2, 4, 4, 4, 4, +}; + +static int berlin_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm_dev, + int duty_ns, int period_ns) +{ + struct berlin_pwm_chip *pwm = to_berlin_pwm_chip(chip); + int prescale = 0; + u32 val, duty, period; + u64 cycles; + + cycles = clk_get_rate(pwm->clk); + cycles *= period_ns; + do_div(cycles, NSEC_PER_SEC); + + while (cycles > BERLIN_PWM_MAX_TCNT) + do_div(cycles, prescaler_diff_table[++prescale]); + + if (cycles > BERLIN_PWM_MAX_TCNT) + return -EINVAL; + + period = cycles; + cycles *= duty_ns; + do_div(cycles, period_ns); + duty = cycles; + + spin_lock(&pwm->lock); + + val = berlin_pwm_readl(pwm, pwm_dev->hwpwm, BERLIN_PWM_CONTROL); + val &= ~BERLIN_PWM_PRESCALE_MASK; + val |= prescale; + berlin_pwm_writel(val, pwm, pwm_dev->hwpwm, BERLIN_PWM_CONTROL); + + berlin_pwm_writel(duty, pwm, pwm_dev->hwpwm, BERLIN_PWM_DUTY); + berlin_pwm_writel(period, pwm, pwm_dev->hwpwm, BERLIN_PWM_TCNT); + + spin_unlock(&pwm->lock); + + return 0; +} + +static int berlin_pwm_set_polarity(struct pwm_chip *chip, + struct pwm_device *pwm_dev, + enum pwm_polarity polarity) +{ + struct berlin_pwm_chip *pwm = to_berlin_pwm_chip(chip); + u32 val; + + spin_lock(&pwm->lock); + + val = berlin_pwm_readl(pwm, pwm_dev->hwpwm, BERLIN_PWM_CONTROL); + + if (polarity == PWM_POLARITY_NORMAL) + val &= ~BERLIN_PWM_INVERT_POLARITY; + else + val |= BERLIN_PWM_INVERT_POLARITY; + + berlin_pwm_writel(val, pwm, pwm_dev->hwpwm, BERLIN_PWM_CONTROL); + + spin_unlock(&pwm->lock); + + return 0; +} + +static int berlin_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm_dev) +{ + struct berlin_pwm_chip *pwm = to_berlin_pwm_chip(chip); + u32 val; + + spin_lock(&pwm->lock); + + val = berlin_pwm_readl(pwm, pwm_dev->hwpwm, BERLIN_PWM_EN); + val |= BERLIN_PWM_ENABLE; + berlin_pwm_writel(val, pwm, pwm_dev->hwpwm, BERLIN_PWM_EN); + + spin_unlock(&pwm->lock); + + return 0; +} + +static void berlin_pwm_disable(struct pwm_chip *chip, + struct pwm_device *pwm_dev) +{ + struct berlin_pwm_chip *pwm = to_berlin_pwm_chip(chip); + u32 val; + + spin_lock(&pwm->lock); + + val = berlin_pwm_readl(pwm, pwm_dev->hwpwm, BERLIN_PWM_EN); + val &= ~BERLIN_PWM_ENABLE; + berlin_pwm_writel(val, pwm, pwm_dev->hwpwm, BERLIN_PWM_EN); + + spin_unlock(&pwm->lock); +} + +static const struct pwm_ops berlin_pwm_ops = { + .config = berlin_pwm_config, + .set_polarity = berlin_pwm_set_polarity, + .enable = berlin_pwm_enable, + .disable = berlin_pwm_disable, + .owner = THIS_MODULE, +}; + +static const struct of_device_id berlin_pwm_match[] = { + { .compatible = "marvell,berlin-pwm" }, + { }, +}; +MODULE_DEVICE_TABLE(of, berlin_pwm_match); + +static int berlin_pwm_probe(struct platform_device *pdev) +{ + struct berlin_pwm_chip *pwm; + struct resource *res; + int ret; + + pwm = devm_kzalloc(&pdev->dev, sizeof(*pwm), GFP_KERNEL); + if (!pwm) + return -ENOMEM; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + pwm->base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(pwm->base)) + return PTR_ERR(pwm->base); + + pwm->clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(pwm->clk)) + return PTR_ERR(pwm->clk); + + ret = clk_prepare_enable(pwm->clk); + if (ret) + return ret; + + pwm->chip.dev = &pdev->dev; + pwm->chip.ops = &berlin_pwm_ops; + pwm->chip.base = -1; + pwm->chip.npwm = 4; + pwm->chip.can_sleep = true; + pwm->chip.of_xlate = of_pwm_xlate_with_flags; + pwm->chip.of_pwm_n_cells = 3; + + spin_lock_init(&pwm->lock); + + ret = pwmchip_add(&pwm->chip); + if (ret < 0) { + dev_err(&pdev->dev, "Failed to add PWM chip: %d\n", ret); + return ret; + } + + platform_set_drvdata(pdev, pwm); + + return 0; +} + +static int berlin_pwm_remove(struct platform_device *pdev) +{ + struct berlin_pwm_chip *pwm = platform_get_drvdata(pdev); + int ret; + + ret = pwmchip_remove(&pwm->chip); + if (ret) + return ret; + + clk_disable_unprepare(pwm->clk); + return 0; +} + +static struct platform_driver berlin_pwm_driver = { + .probe = berlin_pwm_probe, + .remove = berlin_pwm_remove, + .driver = { + .name = "berlin-pwm", + .of_match_table = berlin_pwm_match, + }, +}; +module_platform_driver(berlin_pwm_driver); + +MODULE_AUTHOR("Antoine Tenart <antoine.tenart@free-electrons.com>"); +MODULE_DESCRIPTION("Marvell Berlin PWM driver"); +MODULE_LICENSE("GPL v2");