Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752791AbbHRLiN (ORCPT ); Tue, 18 Aug 2015 07:38:13 -0400 Received: from down.free-electrons.com ([37.187.137.238]:33571 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751652AbbHRLiL (ORCPT ); Tue, 18 Aug 2015 07:38:11 -0400 From: Antoine Tenart To: sebastian.hesselbarth@gmail.com, thierry.reding@gmail.com Cc: Antoine Tenart , zmxu@marvell.com, jszhang@marvell.com, linux-arm-kernel@lists.infradead.org, linux-pwm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v4 1/5] pwm: add the Berlin pwm controller driver Date: Tue, 18 Aug 2015 13:38:04 +0200 Message-Id: <1439897888-10921-2-git-send-email-antoine.tenart@free-electrons.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1439897888-10921-1-git-send-email-antoine.tenart@free-electrons.com> References: <1439897888-10921-1-git-send-email-antoine.tenart@free-electrons.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7602 Lines: 276 Add a PWM controller driver for the Marvell Berlin SoCs. This PWM controller has 4 channels. Signed-off-by: Antoine Tenart Acked-by: Sebastian Hesselbarth --- drivers/pwm/Kconfig | 9 ++ drivers/pwm/Makefile | 1 + drivers/pwm/pwm-berlin.c | 218 +++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 228 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..1bb3958b6e4f --- /dev/null +++ b/drivers/pwm/pwm-berlin.c @@ -0,0 +1,218 @@ +/* + * Marvell Berlin PWM driver + * + * Copyright (C) 2015 Marvell Technology Group Ltd. + * + * Antoine Tenart + * + * 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 +#include +#include +#include +#include +#include +#include + +#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); + + spin_lock(&pwm->lock); + berlin_pwm_writel(BERLIN_PWM_ENABLE, 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); + + clk_disable_unprepare(pwm->clk); + return pwmchip_remove(&pwm->chip); +} + +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 "); +MODULE_DESCRIPTION("Marvell Berlin PWM driver"); +MODULE_LICENSE("GPL v2"); -- 2.5.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/