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Subject[PATCHv10 1/4] pwm: Add Freescale FTM PWM driver support
Date
The FTM PWM device can be found on Vybrid VF610 Tower and
Layerscape LS-1 SoCs.

Signed-off-by: Xiubo Li <Li.Xiubo@freescale.com>
Signed-off-by: Alison Wang <b18965@freescale.com>
Signed-off-by: Jingchang Lu <b35083@freescale.com>
Reviewed-by: Sascha Hauer <s.hauer@pengutronix.de>
Reviewed-by: Yuan Yao <yao.yuan@freescale.com>
---
drivers/pwm/Kconfig | 10 +
drivers/pwm/Makefile | 1 +
drivers/pwm/pwm-fsl-ftm.c | 496 ++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 507 insertions(+)
create mode 100644 drivers/pwm/pwm-fsl-ftm.c

diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index 0b7a3c9..1793562 100644
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -80,6 +80,16 @@ config PWM_EP93XX
To compile this driver as a module, choose M here: the module
will be called pwm-ep93xx.

+config PWM_FSL_FTM
+ tristate "Freescale FlexTimer Module (FTM) PWM support"
+ depends on OF
+ help
+ Generic FTM PWM framework driver for Freescale VF610 and
+ Layerscape LS-1 SoCs.
+
+ To compile this driver as a module, choose M here: the module
+ will be called pwm-fsl-ftm.
+
config PWM_IMX
tristate "i.MX PWM support"
depends on ARCH_MXC
diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile
index d8906ec..7a10e05 100644
--- a/drivers/pwm/Makefile
+++ b/drivers/pwm/Makefile
@@ -5,6 +5,7 @@ obj-$(CONFIG_PWM_ATMEL) += pwm-atmel.o
obj-$(CONFIG_PWM_ATMEL_TCB) += pwm-atmel-tcb.o
obj-$(CONFIG_PWM_BFIN) += pwm-bfin.o
obj-$(CONFIG_PWM_EP93XX) += pwm-ep93xx.o
+obj-$(CONFIG_PWM_FSL_FTM) += pwm-fsl-ftm.o
obj-$(CONFIG_PWM_IMX) += pwm-imx.o
obj-$(CONFIG_PWM_JZ4740) += pwm-jz4740.o
obj-$(CONFIG_PWM_LP3943) += pwm-lp3943.o
diff --git a/drivers/pwm/pwm-fsl-ftm.c b/drivers/pwm/pwm-fsl-ftm.c
new file mode 100644
index 0000000..7a720f2
--- /dev/null
+++ b/drivers/pwm/pwm-fsl-ftm.c
@@ -0,0 +1,496 @@
+/*
+ * Freescale FlexTimer Module (FTM) PWM Driver
+ *
+ * Copyright 2012-2013 Freescale Semiconductor, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+#include <linux/slab.h>
+
+#define FTM_SC 0x00
+#define FTM_SC_CLK_MASK 0x3
+#define FTM_SC_CLK_SHIFT 3
+#define FTM_SC_CLK(c) (((c) + 1) << FTM_SC_CLK_SHIFT)
+#define FTM_SC_PS_MASK 0x7
+#define FTM_SC_PS_SHIFT 0
+
+#define FTM_CNT 0x04
+#define FTM_MOD 0x08
+
+#define FTM_CSC_BASE 0x0C
+#define FTM_CSC_MSB BIT(5)
+#define FTM_CSC_MSA BIT(4)
+#define FTM_CSC_ELSB BIT(3)
+#define FTM_CSC_ELSA BIT(2)
+#define FTM_CSC(_channel) (FTM_CSC_BASE + ((_channel) * 8))
+
+#define FTM_CV_BASE 0x10
+#define FTM_CV(_channel) (FTM_CV_BASE + ((_channel) * 8))
+
+#define FTM_CNTIN 0x4C
+#define FTM_STATUS 0x50
+
+#define FTM_MODE 0x54
+#define FTM_MODE_FTMEN BIT(0)
+#define FTM_MODE_INIT BIT(2)
+#define FTM_MODE_PWMSYNC BIT(3)
+
+#define FTM_SYNC 0x58
+#define FTM_OUTINIT 0x5C
+#define FTM_OUTMASK 0x60
+#define FTM_COMBINE 0x64
+#define FTM_DEADTIME 0x68
+#define FTM_EXTTRIG 0x6C
+#define FTM_POL 0x70
+#define FTM_FMS 0x74
+#define FTM_FILTER 0x78
+#define FTM_FLTCTRL 0x7C
+#define FTM_QDCTRL 0x80
+#define FTM_CONF 0x84
+#define FTM_FLTPOL 0x88
+#define FTM_SYNCONF 0x8C
+#define FTM_INVCTRL 0x90
+#define FTM_SWOCTRL 0x94
+#define FTM_PWMLOAD 0x98
+
+enum fsl_pwm_clk {
+ FSL_PWM_CLK_SYS,
+ FSL_PWM_CLK_FIX,
+ FSL_PWM_CLK_EXT,
+ FSL_PWM_CLK_CNTEN,
+ FSL_PWM_CLK_MAX
+};
+
+struct fsl_pwm_chip {
+ struct pwm_chip chip;
+
+ struct mutex lock;
+
+ unsigned int use_count;
+ unsigned int cnt_select;
+ unsigned int clk_ps;
+
+ void __iomem *base;
+
+ int period_ns;
+
+ struct clk *clk[FSL_PWM_CLK_MAX];
+};
+
+static inline struct fsl_pwm_chip *to_fsl_chip(struct pwm_chip *chip)
+{
+ return container_of(chip, struct fsl_pwm_chip, chip);
+}
+
+static int fsl_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ struct fsl_pwm_chip *fpc = to_fsl_chip(chip);
+
+ return clk_prepare_enable(fpc->clk[FSL_PWM_CLK_SYS]);
+}
+
+static void fsl_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ struct fsl_pwm_chip *fpc = to_fsl_chip(chip);
+
+ clk_disable_unprepare(fpc->clk[FSL_PWM_CLK_SYS]);
+}
+
+static int fsl_pwm_calculate_default_ps(struct fsl_pwm_chip *fpc,
+ enum fsl_pwm_clk index)
+{
+ unsigned long sys_rate, cnt_rate;
+ unsigned long long ratio;
+
+ sys_rate = clk_get_rate(fpc->clk[FSL_PWM_CLK_SYS]);
+ if (!sys_rate)
+ return -EINVAL;
+
+ cnt_rate = clk_get_rate(fpc->clk[fpc->cnt_select]);
+ if (!cnt_rate)
+ return -EINVAL;
+
+ switch (index) {
+ case FSL_PWM_CLK_SYS:
+ fpc->clk_ps = 1;
+ break;
+ case FSL_PWM_CLK_FIX:
+ ratio = 2 * cnt_rate - 1;
+ do_div(ratio, sys_rate);
+ fpc->clk_ps = ratio;
+ break;
+ case FSL_PWM_CLK_EXT:
+ ratio = 4 * cnt_rate - 1;
+ do_div(ratio, sys_rate);
+ fpc->clk_ps = ratio;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static unsigned long fsl_pwm_calculate_cycles(struct fsl_pwm_chip *fpc,
+ unsigned long period_ns)
+{
+ unsigned long long c, c0;
+
+ c = clk_get_rate(fpc->clk[fpc->cnt_select]);
+ c = c * period_ns;
+ do_div(c, 1000000000UL);
+
+ do {
+ c0 = c;
+ do_div(c0, (1 << fpc->clk_ps));
+ if (c0 <= 0xFFFF)
+ return (unsigned long)c0;
+ } while (++fpc->clk_ps < 8);
+
+ return 0;
+}
+
+static unsigned long fsl_pwm_calculate_period_cycles(struct fsl_pwm_chip *fpc,
+ unsigned long period_ns,
+ enum fsl_pwm_clk index)
+{
+ int ret;
+
+ ret = fsl_pwm_calculate_default_ps(fpc, index);
+ if (ret) {
+ dev_err(fpc->chip.dev,
+ "failed to calculate default prescaler: %d\n",
+ ret);
+ return 0;
+ }
+
+ return fsl_pwm_calculate_cycles(fpc, period_ns);
+}
+
+static unsigned long fsl_pwm_calculate_period(struct fsl_pwm_chip *fpc,
+ unsigned long period_ns)
+{
+ enum fsl_pwm_clk m0, m1;
+ unsigned long fix_rate, ext_rate, cycles;
+
+ cycles = fsl_pwm_calculate_period_cycles(fpc, period_ns,
+ FSL_PWM_CLK_SYS);
+ if (cycles) {
+ fpc->cnt_select = FSL_PWM_CLK_SYS;
+ return cycles;
+ }
+
+ fix_rate = clk_get_rate(fpc->clk[FSL_PWM_CLK_FIX]);
+ ext_rate = clk_get_rate(fpc->clk[FSL_PWM_CLK_EXT]);
+
+ if (fix_rate > ext_rate) {
+ m0 = FSL_PWM_CLK_FIX;
+ m1 = FSL_PWM_CLK_EXT;
+ } else {
+ m0 = FSL_PWM_CLK_EXT;
+ m1 = FSL_PWM_CLK_FIX;
+ }
+
+ cycles = fsl_pwm_calculate_period_cycles(fpc, period_ns, m0);
+ if (cycles) {
+ fpc->cnt_select = m0;
+ return cycles;
+ }
+
+ fpc->cnt_select = m1;
+
+ return fsl_pwm_calculate_period_cycles(fpc, period_ns, m1);
+}
+
+static unsigned long fsl_pwm_calculate_duty(struct fsl_pwm_chip *fpc,
+ unsigned long period_ns,
+ unsigned long duty_ns)
+{
+ unsigned long long val, duty;
+
+ val = readl(fpc->base + FTM_MOD);
+ duty = duty_ns * (val + 1);
+ do_div(duty, period_ns);
+
+ return (unsigned long)duty;
+}
+
+static int fsl_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
+ int duty_ns, int period_ns)
+{
+ struct fsl_pwm_chip *fpc = to_fsl_chip(chip);
+ u32 val, period, duty;
+
+ mutex_lock(&fpc->lock);
+
+ /*
+ * The Freescale FTM controller supports only a single period for
+ * all PWM channels, therefore incompatible changes need to be
+ * refused.
+ */
+ if (fpc->period_ns && fpc->period_ns != period_ns) {
+ dev_err(fpc->chip.dev,
+ "conflicting period requested for PWM %u\n",
+ pwm->hwpwm);
+ mutex_unlock(&fpc->lock);
+ return -EBUSY;
+ }
+
+ if (!fpc->period_ns && duty_ns) {
+ period = fsl_pwm_calculate_period(fpc, period_ns);
+ if (!period) {
+ dev_err(fpc->chip.dev, "failed to calculate period\n");
+ mutex_unlock(&fpc->lock);
+ return -EINVAL;
+ }
+
+ val = readl(fpc->base + FTM_SC);
+ val &= ~(FTM_SC_PS_MASK << FTM_SC_PS_SHIFT);
+ val |= fpc->clk_ps;
+ writel(val, fpc->base + FTM_SC);
+ writel(period - 1, fpc->base + FTM_MOD);
+
+ fpc->period_ns = period_ns;
+ }
+
+ mutex_unlock(&fpc->lock);
+
+ duty = fsl_pwm_calculate_duty(fpc, period_ns, duty_ns);
+
+ writel(FTM_CSC_MSB | FTM_CSC_ELSB, fpc->base + FTM_CSC(pwm->hwpwm));
+ writel(duty, fpc->base + FTM_CV(pwm->hwpwm));
+
+ return 0;
+}
+
+static int fsl_pwm_set_polarity(struct pwm_chip *chip,
+ struct pwm_device *pwm,
+ enum pwm_polarity polarity)
+{
+ struct fsl_pwm_chip *fpc = to_fsl_chip(chip);
+ u32 val;
+
+ val = readl(fpc->base + FTM_POL);
+
+ if (polarity == PWM_POLARITY_INVERSED)
+ val |= BIT(pwm->hwpwm);
+ else
+ val &= ~BIT(pwm->hwpwm);
+
+ writel(val, fpc->base + FTM_POL);
+
+ return 0;
+}
+
+static int fsl_counter_clock_enable(struct fsl_pwm_chip *fpc)
+{
+ u32 val;
+ int ret;
+
+ if (fpc->use_count != 0)
+ return 0;
+
+ /* select counter clock source */
+ val = readl(fpc->base + FTM_SC);
+ val &= ~(FTM_SC_CLK_MASK << FTM_SC_CLK_SHIFT);
+ val |= FTM_SC_CLK(fpc->cnt_select);
+ writel(val, fpc->base + FTM_SC);
+
+ ret = clk_prepare_enable(fpc->clk[fpc->cnt_select]);
+ if (ret)
+ return ret;
+
+ ret = clk_prepare_enable(fpc->clk[FSL_PWM_CLK_CNTEN]);
+ if (ret) {
+ clk_disable_unprepare(fpc->clk[fpc->cnt_select]);
+ return ret;
+ }
+
+ fpc->use_count++;
+
+ return 0;
+}
+
+static int fsl_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ struct fsl_pwm_chip *fpc = to_fsl_chip(chip);
+ u32 val;
+ int ret;
+
+ mutex_lock(&fpc->lock);
+ val = readl(fpc->base + FTM_OUTMASK);
+ val &= ~BIT(pwm->hwpwm);
+ writel(val, fpc->base + FTM_OUTMASK);
+
+ ret = fsl_counter_clock_enable(fpc);
+ mutex_unlock(&fpc->lock);
+
+ return ret;
+}
+
+static void fsl_counter_clock_disable(struct fsl_pwm_chip *fpc)
+{
+ u32 val;
+
+ /*
+ * already disabled, do nothing (perhaps output warning message
+ * to catch unbalanced calls?
+ */
+ if (fpc->use_count == 0)
+ return;
+
+ /* there are still users, so can't disable yet */
+ if (--fpc->use_count > 0)
+ return;
+
+ /* no users left, disable PWM counter clock */
+ val = readl(fpc->base + FTM_SC);
+ val &= ~(FTM_SC_CLK_MASK << FTM_SC_CLK_SHIFT);
+ writel(val, fpc->base + FTM_SC);
+
+ clk_disable_unprepare(fpc->clk[FSL_PWM_CLK_CNTEN]);
+ clk_disable_unprepare(fpc->clk[fpc->cnt_select]);
+}
+
+static void fsl_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ struct fsl_pwm_chip *fpc = to_fsl_chip(chip);
+ u32 val;
+
+ mutex_lock(&fpc->lock);
+ val = readl(fpc->base + FTM_OUTMASK);
+ val |= BIT(pwm->hwpwm);
+ writel(val, fpc->base + FTM_OUTMASK);
+
+ fsl_counter_clock_disable(fpc);
+
+ val = readl(fpc->base + FTM_OUTMASK);
+
+ if ((val & 0xFF) == 0xFF)
+ fpc->period_ns = 0;
+
+ mutex_unlock(&fpc->lock);
+}
+
+static const struct pwm_ops fsl_pwm_ops = {
+ .request = fsl_pwm_request,
+ .free = fsl_pwm_free,
+ .config = fsl_pwm_config,
+ .set_polarity = fsl_pwm_set_polarity,
+ .enable = fsl_pwm_enable,
+ .disable = fsl_pwm_disable,
+ .owner = THIS_MODULE,
+};
+
+static int fsl_pwm_init(struct fsl_pwm_chip *fpc)
+{
+ int ret;
+
+ ret = clk_prepare_enable(fpc->clk[FSL_PWM_CLK_SYS]);
+ if (ret)
+ return ret;
+
+ writel(0x00, fpc->base + FTM_CNTIN);
+ writel(0x00, fpc->base + FTM_OUTINIT);
+ writel(0xFF, fpc->base + FTM_OUTMASK);
+
+ clk_disable_unprepare(fpc->clk[FSL_PWM_CLK_SYS]);
+
+ return 0;
+}
+
+static int fsl_pwm_probe(struct platform_device *pdev)
+{
+ struct fsl_pwm_chip *fpc;
+ struct resource *res;
+ int ret;
+
+ fpc = devm_kzalloc(&pdev->dev, sizeof(*fpc), GFP_KERNEL);
+ if (!fpc)
+ return -ENOMEM;
+
+ mutex_init(&fpc->lock);
+
+ fpc->chip.dev = &pdev->dev;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ fpc->base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(fpc->base))
+ return PTR_ERR(fpc->base);
+
+ fpc->clk[FSL_PWM_CLK_SYS] = devm_clk_get(&pdev->dev, "ftm_sys");
+ if (IS_ERR(fpc->clk[FSL_PWM_CLK_SYS])) {
+ dev_err(&pdev->dev, "failed to get \"ftm_sys\" clock\n");
+ return PTR_ERR(fpc->clk[FSL_PWM_CLK_SYS]);
+ }
+
+ fpc->clk[FSL_PWM_CLK_FIX] = devm_clk_get(fpc->chip.dev, "ftm_fix");
+ if (IS_ERR(fpc->clk[FSL_PWM_CLK_FIX]))
+ return PTR_ERR(fpc->clk[FSL_PWM_CLK_FIX]);
+
+ fpc->clk[FSL_PWM_CLK_EXT] = devm_clk_get(fpc->chip.dev, "ftm_ext");
+ if (IS_ERR(fpc->clk[FSL_PWM_CLK_EXT]))
+ return PTR_ERR(fpc->clk[FSL_PWM_CLK_EXT]);
+
+ fpc->clk[FSL_PWM_CLK_CNTEN] =
+ devm_clk_get(fpc->chip.dev, "ftm_cnt_clk_en");
+ if (IS_ERR(fpc->clk[FSL_PWM_CLK_CNTEN]))
+ return PTR_ERR(fpc->clk[FSL_PWM_CLK_CNTEN]);
+
+ fpc->chip.ops = &fsl_pwm_ops;
+ fpc->chip.of_xlate = of_pwm_xlate_with_flags;
+ fpc->chip.of_pwm_n_cells = 3;
+ fpc->chip.base = -1;
+ fpc->chip.npwm = 8;
+
+ ret = pwmchip_add(&fpc->chip);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "failed to add PWM chip : %d\n", ret);
+ return ret;
+ }
+
+ platform_set_drvdata(pdev, fpc);
+
+ return fsl_pwm_init(fpc);
+}
+
+static int fsl_pwm_remove(struct platform_device *pdev)
+{
+ struct fsl_pwm_chip *fpc = platform_get_drvdata(pdev);
+
+ return pwmchip_remove(&fpc->chip);
+}
+
+static const struct of_device_id fsl_pwm_dt_ids[] = {
+ { .compatible = "fsl,vf610-ftm-pwm", },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, fsl_pwm_dt_ids);
+
+static struct platform_driver fsl_pwm_driver = {
+ .driver = {
+ .name = "fsl-ftm-pwm",
+ .of_match_table = fsl_pwm_dt_ids,
+ },
+ .probe = fsl_pwm_probe,
+ .remove = fsl_pwm_remove,
+};
+module_platform_driver(fsl_pwm_driver);
+
+MODULE_DESCRIPTION("Freescale FlexTimer Module PWM Driver");
+MODULE_AUTHOR("Xiubo Li <Li.Xiubo@freescale.com>");
+MODULE_ALIAS("platform:fsl-ftm-pwm");
+MODULE_LICENSE("GPL");
--
1.8.4



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