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Message-Id: <2ab3d3afe800febece9994d55813ab71b27c2d25.1354810562.git.linux-arm@overkiz.com> Date: Thu, 6 Dec 2012 17:45:23 +0100 From: Boris BREZILLON <linux-arm@...rkiz.com> To: Thierry Reding <thierry.reding@...onic-design.de>, Andrew Victor <linux@...im.org.za>, Nicolas Ferre <nicolas.ferre@...el.com>, Jean-Christophe Plagniol-Villard <plagnioj@...osoft.com>, Russell King <linux@....linux.org.uk>, Haavard Skinnemoen <hskinnemoen@...il.com>, Hans-Christian Egtvedt <egtvedt@...fundet.no> Cc: linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org, Boris BREZILLON <linux-arm@...rkiz.com> Subject: [PATCH 1/1] pwm: atmel: add Timer Counter Block PWM driver Add TCB PWM driver. Add device tree binding. Signed-off-by: Boris BREZILLON <linux-arm@...rkiz.com> -- create mode 100644 Documentation/devicetree/bindings/pwm/atmel-tcb-pwm.txt create mode 100644 drivers/pwm/pwm-atmel-tcb.c diff --git a/Documentation/devicetree/bindings/pwm/atmel-tcb-pwm.txt b/Documentation/devicetree/bindings/pwm/atmel-tcb-pwm.txt new file mode 100644 index 0000000..7644889 --- /dev/null +++ b/Documentation/devicetree/bindings/pwm/atmel-tcb-pwm.txt @@ -0,0 +1,15 @@ +Atmel TCB PWM controller + +Required properties: +- compatible: should be "atmel,tcb-pwm" +- #pwm-cells: should be 2. The first cell specifies the per-chip index + of the PWM to use and the second cell is the period in nanoseconds. +- atmel,tc-block: the Timer Counter block to use as a PWM chip. + +Example: + +pwm: pwm@...64000 { + compatible = "fsl,imx28-pwm", "fsl,imx23-pwm"; + #pwm-cells = <2>; + atmel,tc-block = <1>; +}; diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig index e513cd9..bda52f7 100644 --- a/drivers/pwm/Kconfig +++ b/drivers/pwm/Kconfig @@ -37,6 +37,14 @@ config PWM_AB8500 To compile this driver as a module, choose M here: the module will be called pwm-ab8500. +config PWM_ATMEL_TCB + bool "TC Block PWM" + depends on ATMEL_TCLIB + select HAVE_PWM + default y + help + Select this to get 6 PWM devices. + config PWM_BFIN tristate "Blackfin PWM support" depends on BFIN_GPTIMERS diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile index 62a2963..94ba21e 100644 --- a/drivers/pwm/Makefile +++ b/drivers/pwm/Makefile @@ -1,5 +1,6 @@ obj-$(CONFIG_PWM) += core.o obj-$(CONFIG_PWM_AB8500) += pwm-ab8500.o +obj-$(CONFIG_PWM_ATMEL_TCB) += pwm-atmel-tcb.o obj-$(CONFIG_PWM_BFIN) += pwm-bfin.o obj-$(CONFIG_PWM_IMX) += pwm-imx.o obj-$(CONFIG_PWM_JZ4740) += pwm-jz4740.o diff --git a/drivers/pwm/pwm-atmel-tcb.c b/drivers/pwm/pwm-atmel-tcb.c new file mode 100644 index 0000000..d5a87cc --- /dev/null +++ b/drivers/pwm/pwm-atmel-tcb.c @@ -0,0 +1,335 @@ +/* + * Copyright (C) Overkiz SAS 2012 + * + * Author: Boris BREZILLON <b.brezillon@...rkiz.com> + * License terms: GNU General Public License (GPL) version 2 + */ +#include <linux/module.h> +#include <linux/init.h> +#include <linux/clocksource.h> +#include <linux/clockchips.h> +#include <linux/interrupt.h> +#include <linux/irq.h> + +#include <linux/clk.h> +#include <linux/err.h> +#include <linux/ioport.h> +#include <linux/io.h> +#include <linux/platform_device.h> +#include <linux/atmel_tc.h> +#include <linux/pwm.h> +#include <linux/of_device.h> +#include <linux/slab.h> + +#define NPWM 6 + +struct atmel_tcb_pwm_device { + u8 polarity : 1; + u8 clk : 3; + u32 duty; + u32 period; +}; + +struct atmel_tcb_pwm_chip { + struct pwm_chip chip; + spinlock_t lock; + struct atmel_tc *tc; + struct atmel_tcb_pwm_device pwms[NPWM]; +}; + +static inline struct atmel_tcb_pwm_chip *to_atmel_tcb_pwm_chip(struct pwm_chip *chip) +{ + return container_of(chip, struct atmel_tcb_pwm_chip, chip); +} + +static int atmel_tcb_pwm_set_polarity (struct pwm_chip *chip, struct pwm_device *pwm, + enum pwm_polarity polarity) +{ + struct atmel_tcb_pwm_device *tcbpwm = + (struct atmel_tcb_pwm_device *)pwm_get_chip_data(pwm); + + tcbpwm->polarity = polarity; + + return 0; +} + +static int atmel_tcb_pwm_request (struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct atmel_tcb_pwm_chip *tcbpwmc = to_atmel_tcb_pwm_chip(chip); + struct atmel_tcb_pwm_device *tcbpwm = &(tcbpwmc->pwms[pwm->hwpwm]); + struct atmel_tc *tc = tcbpwmc->tc; + void __iomem *regs = tc->regs; + u32 reg; + + pwm_set_chip_data(pwm, tcbpwm); + tcbpwm->polarity = PWM_POLARITY_NORMAL; + tcbpwm->duty = 0; + tcbpwm->period = 0; + tcbpwm->clk = 0; + spin_lock(&tcbpwmc->lock); + reg = __raw_readl (regs + ATMEL_TC_REG(pwm->hwpwm / 2, CMR)); + if (reg & ATMEL_TC_WAVE) { + tcbpwm->duty = __raw_readl (regs + ((pwm->hwpwm % 2) ? + ATMEL_TC_REG(pwm->hwpwm / 2, RB) : + ATMEL_TC_REG(pwm->hwpwm / 2, RA))); + + + tcbpwm->clk = reg & ATMEL_TC_TCCLKS; + tcbpwm->period = __raw_readl (regs + ATMEL_TC_REG(pwm->hwpwm / 2, RC)); + reg &= (ATMEL_TC_TCCLKS | + ATMEL_TC_ACPA | ATMEL_TC_ACPC | ATMEL_TC_AEEVT | ATMEL_TC_ASWTRG | + ATMEL_TC_BCPB | ATMEL_TC_BCPC | ATMEL_TC_BEEVT | ATMEL_TC_BSWTRG); + } + else + reg = 0; + reg |= ATMEL_TC_WAVE | ATMEL_TC_WAVESEL_UP_AUTO | ATMEL_TC_EEVT_XC0; + __raw_writel (reg, regs + ATMEL_TC_REG(pwm->hwpwm / 2, CMR)); + spin_unlock(&tcbpwmc->lock); + + clk_enable (tc->clk[pwm->hwpwm / 2]); + + return 0; +} + +static void atmel_tcb_pwm_free (struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct atmel_tcb_pwm_chip *tcbpwmc = to_atmel_tcb_pwm_chip(chip); + struct atmel_tc *tc = tcbpwmc->tc; + + clk_disable (tc->clk[pwm->hwpwm / 2]); +} + +static void atmel_tcb_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct atmel_tcb_pwm_chip *tcbpwmc = to_atmel_tcb_pwm_chip(chip); + struct atmel_tcb_pwm_device *tcbpwm = + (struct atmel_tcb_pwm_device *)pwm_get_chip_data(pwm); + struct atmel_tc *tc = tcbpwmc->tc; + void __iomem *regs = tc->regs; + u32 reg; + u32 cmr = 0; + u8 shift = pwm->hwpwm % 2 ? 8 : 0; + enum pwm_polarity polarity = tcbpwm->polarity; + + if (tcbpwm->duty == 0) + polarity = !polarity; + + if (polarity) + cmr |= ATMEL_TC_ASWTRG_CLEAR; + else + cmr |= ATMEL_TC_ASWTRG_SET; + + cmr <<= shift; + + spin_lock(&tcbpwmc->lock); + reg = __raw_readl(regs + ATMEL_TC_REG(pwm->hwpwm / 2, CMR)); + reg &= ~((ATMEL_TC_ACPA | ATMEL_TC_ACPC | ATMEL_TC_AEEVT | ATMEL_TC_BSWTRG) << shift); + reg |= cmr; + __raw_writel (reg, regs + ATMEL_TC_REG(pwm->hwpwm / 2, CMR)); + __raw_writel (ATMEL_TC_SWTRG, regs + ATMEL_TC_REG(pwm->hwpwm / 2, CCR)); + if (!(reg & (ATMEL_TC_ACPC | ATMEL_TC_BCPC))) + __raw_writel(ATMEL_TC_SWTRG | ATMEL_TC_CLKDIS, regs + ATMEL_TC_REG(pwm->hwpwm / 2, CCR)); + else + __raw_writel (ATMEL_TC_SWTRG, regs + ATMEL_TC_REG(pwm->hwpwm / 2, CCR)); + spin_unlock(&tcbpwmc->lock); +} + +static int atmel_tcb_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct atmel_tcb_pwm_chip *tcbpwmc = to_atmel_tcb_pwm_chip(chip); + struct atmel_tcb_pwm_device *tcbpwm = + (struct atmel_tcb_pwm_device *)pwm_get_chip_data(pwm); + struct atmel_tc *tc = tcbpwmc->tc; + void __iomem *regs = tc->regs; + u32 reg; + u32 cmr = 0; + u8 shift = pwm->hwpwm % 2 ? 8 : 0; + enum pwm_polarity polarity = tcbpwm->polarity; + + if (tcbpwm->duty == 0) + polarity = !polarity; + + if (polarity) + cmr |= ATMEL_TC_ASWTRG_CLEAR; + else + cmr |= ATMEL_TC_ASWTRG_SET; + + if (tcbpwm->duty != tcbpwm->period && tcbpwm->duty > 0) { + if (polarity) + cmr |= ATMEL_TC_ACPA_SET | ATMEL_TC_ACPC_CLEAR; + else + cmr |= ATMEL_TC_ACPA_CLEAR | ATMEL_TC_ACPC_SET; + } + + cmr <<= shift; + cmr |= tcbpwm->clk; + + spin_lock(&tcbpwmc->lock); + reg = __raw_readl(regs + ATMEL_TC_REG(pwm->hwpwm / 2, CMR)); + reg &= ~(((ATMEL_TC_ACPA | + ATMEL_TC_ACPC | + ATMEL_TC_AEEVT | + ATMEL_TC_ASWTRG) << shift) | + ATMEL_TC_TCCLKS); + reg |= cmr; + __raw_writel (reg, regs + ATMEL_TC_REG(pwm->hwpwm / 2, CMR)); + __raw_writel(tcbpwm->duty, regs + ((pwm->hwpwm % 2) ? ATMEL_TC_REG(pwm->hwpwm / 2, RB) : ATMEL_TC_REG(pwm->hwpwm / 2, RA))); + __raw_writel(tcbpwm->period, regs + ATMEL_TC_REG(pwm->hwpwm / 2, RC)); + __raw_writel (ATMEL_TC_CLKEN | ATMEL_TC_SWTRG, regs + ATMEL_TC_REG(pwm->hwpwm / 2, CCR)); + spin_unlock(&tcbpwmc->lock); + return 0; +} + +static int atmel_tcb_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, + int duty_ns, int period_ns) +{ + struct atmel_tcb_pwm_chip *tcbpwmc = to_atmel_tcb_pwm_chip(chip); + struct atmel_tcb_pwm_device *tcbpwm = + (struct atmel_tcb_pwm_device *)pwm_get_chip_data(pwm); + struct atmel_tcb_pwm_device *atcbpwm = &(tcbpwmc->pwms[pwm->hwpwm % 2 ? pwm->hwpwm - 1 : pwm->hwpwm + 1]); + struct atmel_tc *tc = tcbpwmc->tc; + int i; + int slowclk = 0; + u32 period; + u32 rate = clk_get_rate(tc->clk[pwm->hwpwm / 2]); + u64 min; + u64 max; + u64 duty; + + for (i = 0; i < 5; ++i) { + if (atmel_tc_divisors[i] == 0) { + slowclk = i; + continue; + } + min = div_u64 (1000000000, div_u64 (rate, atmel_tc_divisors[i])); + max = min << tc->tcb_config->counter_width; + if (max >= period_ns) + break; + } + + if (i == 5) { + i = slowclk; + rate = 32768; + min = div_u64 (1000000000, rate); + max = min << 16; + + if (max < period_ns) + return -ERANGE; + } + + duty = div_u64 (duty_ns, min); + duty &= ((u64)(1 << tc->tcb_config->counter_width) - 1); + + period = div_u64 (period_ns, min); + period &= ((u64)(1 << tc->tcb_config->counter_width) - 1); + + if ((atcbpwm->duty > 0 && atcbpwm->duty != atcbpwm->period) && + (atcbpwm->clk != i || atcbpwm->period != period)) { + dev_err(chip->dev, "failed to configure period_ns\n"); + return -EINVAL; + } + + tcbpwm->period = period; + tcbpwm->clk = i; + tcbpwm->duty = duty; + + if (test_bit(PWMF_ENABLED, &pwm->flags)) + atmel_tcb_pwm_enable(chip, pwm); + + return 0; +} + +static const struct pwm_ops atmel_tcb_pwm_ops = { + .set_polarity = atmel_tcb_pwm_set_polarity, + .request = atmel_tcb_pwm_request, + .free = atmel_tcb_pwm_free, + .config = atmel_tcb_pwm_config, + .enable = atmel_tcb_pwm_enable, + .disable = atmel_tcb_pwm_disable, +}; + +static int __devinit atmel_tcb_pwm_probe(struct platform_device *pdev) +{ + struct atmel_tcb_pwm_chip *tcbpwm; + struct device_node *np = pdev->dev.of_node; + struct atmel_tc *tc; + int err; + int tcblock; + + + err = of_property_read_u32(np, "tc-block", &tcblock); + if (err < 0) { + dev_err(&pdev->dev, + "failed to get tc block number from device tree (error: %d)\n", err); + return err; + } + + tc = atmel_tc_alloc(tcblock, "tcb-pwm"); + if (tc == NULL) { + dev_err(&pdev->dev, "failed to allocate Timer Counter Block\n"); + return -ENOMEM; + } + + tcbpwm = kzalloc(sizeof(*tcbpwm), GFP_KERNEL); + if (tcbpwm == NULL) { + dev_err(&pdev->dev, "failed to allocate memory\n"); + return -ENOMEM; + } + + tcbpwm->chip.dev = &pdev->dev; + tcbpwm->chip.ops = &atmel_tcb_pwm_ops; + tcbpwm->chip.base = pdev->id; + tcbpwm->chip.npwm = NPWM; + tcbpwm->tc = tc; + + spin_lock_init(&tcbpwm->lock); + + err = pwmchip_add(&tcbpwm->chip); + if (err < 0) { + kfree(tcbpwm); + return err; + } + + dev_dbg(&pdev->dev, "pwm probe successful\n"); + platform_set_drvdata(pdev, tcbpwm); + + return 0; +} + +static int __devexit atmel_tcb_pwm_remove(struct platform_device *pdev) +{ + struct atmel_tcb_pwm_chip *tcbpwm = platform_get_drvdata(pdev); + int err; + + err = pwmchip_remove(&tcbpwm->chip); + if (err < 0) + return err; + + atmel_tc_free(tcbpwm->tc); + + dev_dbg(&pdev->dev, "pwm driver removed\n"); + kfree(tcbpwm); + + return 0; +} + +static struct of_device_id atmel_tcb_pwm_dt_ids[] = { + { .compatible = "atmel,tcb-pwm", }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, mxs_pwm_dt_ids); + +static struct platform_driver atmel_tcb_pwm_driver = { + .driver = { + .name = "atmel-tcb-pwm", + .of_match_table = of_match_ptr(atmel_tcb_pwm_dt_ids), + }, + .probe = atmel_tcb_pwm_probe, + .remove = __devexit_p(atmel_tcb_pwm_remove), +}; +module_platform_driver(atmel_tcb_pwm_driver); + +MODULE_AUTHOR("Boris BREZILLON <b.brezillon@...rkiz.com>"); +MODULE_DESCRIPTION("Atmel Timer Counter Pulse Width Modulation Driver"); +MODULE_ALIAS("platform:atmel-tcb-pwm"); +MODULE_LICENSE("GPL v2"); -- 1.7.0.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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