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Subject[RFCv2][PATCHv5 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>
---
drivers/pwm/Kconfig | 10 ++
drivers/pwm/Makefile | 1 +
drivers/pwm/pwm-fsl-ftm.c | 401 ++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 412 insertions(+)
create mode 100644 drivers/pwm/pwm-fsl-ftm.c

diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index 75840b5..8144fb0 100644
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -62,6 +62,16 @@ config PWM_BFIN
To compile this driver as a module, choose M here: the module
will be called pwm-bfin.

+config PWM_FSL_FTM
+ tristate "Freescale 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 77a8c18..f383784 100644
--- a/drivers/pwm/Makefile
+++ b/drivers/pwm/Makefile
@@ -3,6 +3,7 @@ obj-$(CONFIG_PWM_SYSFS) += sysfs.o
obj-$(CONFIG_PWM_AB8500) += pwm-ab8500.o
obj-$(CONFIG_PWM_ATMEL_TCB) += pwm-atmel-tcb.o
obj-$(CONFIG_PWM_BFIN) += pwm-bfin.o
+obj-$(CONFIG_PWM_FSL_FTM) += pwm-fsl-ftm.o
obj-$(CONFIG_PWM_IMX) += pwm-imx.o
obj-$(CONFIG_PWM_JZ4740) += pwm-jz4740.o
obj-$(CONFIG_PWM_LPC32XX) += pwm-lpc32xx.o
diff --git a/drivers/pwm/pwm-fsl-ftm.c b/drivers/pwm/pwm-fsl-ftm.c
new file mode 100644
index 0000000..6ee20eb
--- /dev/null
+++ b/drivers/pwm/pwm-fsl-ftm.c
@@ -0,0 +1,401 @@
+/*
+ * Freescale 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/module.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/pwm.h>
+#include <linux/of_address.h>
+#include <dt-bindings/clock/vf610-clock.h>
+
+#define FTM_SC 0x00
+#define FTMSC_CLK_MASK 0x03
+#define FTMSC_CLK_OFFSET 0x03
+#define FTMSC_CLKSYS (0x01 << 3)
+#define FTMSC_CLKFIX (0x02 << 3)
+#define FTMSC_CLKEXT (0x03 << 3)
+#define FTMSC_PS_MASK 0x07
+#define FTMSC_PS_OFFSET 0x00
+
+#define FTM_CNT 0x04
+#define FTM_MOD 0x08
+
+#define FTM_CSC_BASE 0x0C
+#define FTM_CSC(_channel) (FTM_CSC_BASE + ((_channel) * 8))
+#define FTMCnSC_MSB BIT(5)
+#define FTMCnSC_MSA BIT(4)
+#define FTMCnSC_ELSB BIT(3)
+#define FTMCnSC_ELSA BIT(2)
+
+#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 FTMMODE_FTMEN BIT(0)
+#define FTMMODE_INIT BIT(2)
+#define FTMMODE_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
+
+#define FTM_CNTIN_VAL 0x00
+#define FTM_MAX_CHANNEL 8
+
+struct fsl_pwm_chip {
+ struct pwm_chip chip;
+
+ struct clk *sys_clk;
+ struct clk *counter_clk;
+ unsigned int counter_clk_select;
+ unsigned int counter_clk_enable;
+ unsigned int clk_ps;
+
+ void __iomem *base;
+};
+
+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)
+{
+ int ret;
+ struct fsl_pwm_chip *fpc;
+
+ fpc = to_fsl_chip(chip);
+
+ ret = clk_prepare_enable(fpc->sys_clk);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+static void fsl_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ struct fsl_pwm_chip *fpc;
+
+ fpc = to_fsl_chip(chip);
+
+ clk_disable_unprepare(fpc->sys_clk);
+}
+
+static unsigned long fsl_rate_to_cycles(struct fsl_pwm_chip *fpc,
+ unsigned long time_ns)
+{
+ unsigned long long c;
+ unsigned long ps = 1 << fpc->clk_ps;
+
+ c = clk_get_rate(fpc->counter_clk);
+ c = c * time_ns;
+ do_div(c, 1000000000UL);
+ do_div(c, ps);
+
+ return (unsigned long)c;
+}
+
+static int fsl_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
+ int duty_ns, int period_ns)
+{
+ unsigned long period_cycles, duty_cycles;
+ unsigned long cntin = FTM_CNTIN_VAL;
+ struct fsl_pwm_chip *fpc;
+
+ fpc = to_fsl_chip(chip);
+
+ period_cycles = fsl_rate_to_cycles(fpc, period_ns);
+ if (period_cycles > 0xFFFF) {
+ dev_err(chip->dev, "required PWM period cycles(%lu) overflow "
+ "16-bits counter!\n", period_cycles);
+ return -EINVAL;
+ }
+
+ duty_cycles = fsl_rate_to_cycles(fpc, duty_ns);
+ if (duty_cycles >= 0xFFFF) {
+ dev_err(chip->dev, "required PWM duty cycles(%lu) overflow "
+ "16-bits counter!\n", duty_cycles);
+ return -EINVAL;
+ }
+
+ writel(FTMCnSC_MSB | FTMCnSC_ELSB, fpc->base + FTM_CSC(pwm->hwpwm));
+
+ writel(0xF0, fpc->base + FTM_OUTMASK);
+ writel(0x0F, fpc->base + FTM_OUTINIT);
+ writel(FTM_CNTIN_VAL, fpc->base + FTM_CNTIN);
+
+ writel(period_cycles + cntin - 1, fpc->base + FTM_MOD);
+ writel(duty_cycles + cntin, 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)
+{
+ unsigned long reg;
+ struct fsl_pwm_chip *fpc;
+
+ fpc = to_fsl_chip(chip);
+
+ reg = readl(fpc->base + FTM_POL);
+ if (polarity == PWM_POLARITY_INVERSED)
+ reg |= BIT(pwm->hwpwm);
+ else
+ reg &= ~BIT(pwm->hwpwm);
+ writel(reg, fpc->base + FTM_POL);
+
+ return 0;
+}
+
+static int fsl_counter_clock_enable(struct fsl_pwm_chip *fpc)
+{
+ int ret;
+ unsigned long reg;
+
+ if (fpc->counter_clk_enable++)
+ return 0;
+
+ ret = clk_prepare_enable(fpc->counter_clk);
+ if (ret)
+ return ret;
+
+ reg = readl(fpc->base + FTM_SC);
+ reg &= ~((FTMSC_CLK_MASK << FTMSC_CLK_OFFSET) |
+ (FTMSC_PS_MASK << FTMSC_PS_OFFSET));
+ /* select counter clock source */
+ switch (fpc->counter_clk_select) {
+ case VF610_CLK_FTM0:
+ reg |= FTMSC_CLKSYS;
+ break;
+ case VF610_CLK_FTM0_FIX_SEL:
+ reg |= FTMSC_CLKFIX;
+ break;
+ case VF610_CLK_FTM0_EXT_SEL:
+ reg |= FTMSC_CLKEXT;
+ break;
+ default:
+ break;
+ }
+ reg |= fpc->clk_ps;
+ writel(reg, fpc->base + FTM_SC);
+
+ return 0;
+}
+
+static int fsl_counter_clock_disable(struct fsl_pwm_chip *fpc)
+{
+ unsigned long reg;
+
+ if (--fpc->counter_clk_enable)
+ return 0;
+
+ writel(0xFF, fpc->base + FTM_OUTMASK);
+ reg = readl(fpc->base + FTM_SC);
+ reg &= ~(FTMSC_CLK_MASK << FTMSC_CLK_OFFSET);
+ writel(reg, fpc->base + FTM_SC);
+
+ clk_disable_unprepare(fpc->counter_clk);
+
+ return 0;
+}
+
+static int fsl_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ struct fsl_pwm_chip *fpc;
+
+ fpc = to_fsl_chip(chip);
+
+ fsl_counter_clock_enable(fpc);
+
+ return 0;
+}
+
+static void fsl_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ struct fsl_pwm_chip *fpc;
+
+ fpc = to_fsl_chip(chip);
+
+ fsl_counter_clock_disable(fpc);
+}
+
+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_calculate_ps(struct fsl_pwm_chip *fpc)
+{
+ unsigned long long sys_rate, counter_rate, ratio;
+
+ sys_rate = clk_get_rate(fpc->sys_clk);
+ if (!sys_rate)
+ return -EINVAL;
+
+ counter_rate = clk_get_rate(fpc->counter_clk);
+ if (!counter_rate) {
+ fpc->counter_clk = fpc->sys_clk;
+ fpc->counter_clk_select = VF610_CLK_FTM0;
+ dev_warn(fpc->chip.dev,
+ "the counter source clock is a dummy clock, "
+ "so select the system clock as default!\n");
+ }
+
+ switch (fpc->counter_clk_select) {
+ case VF610_CLK_FTM0_FIX_SEL:
+ ratio = 2 * counter_rate - 1;
+ do_div(ratio, sys_rate);
+ fpc->clk_ps = ratio;
+ break;
+ case VF610_CLK_FTM0_EXT_SEL:
+ ratio = 4 * counter_rate - 1;
+ do_div(ratio, sys_rate);
+ fpc->clk_ps = ratio;
+ break;
+ case VF610_CLK_FTM0:
+ fpc->clk_ps = 7;
+ default:
+ break;
+ }
+
+ return 0;
+}
+
+static int fsl_pwm_parse_clk_ps(struct fsl_pwm_chip *fpc)
+{
+ int ret;
+ struct of_phandle_args clkspec;
+ struct device_node *np = fpc->chip.dev->of_node;
+
+ fpc->sys_clk = devm_clk_get(fpc->chip.dev, "ftm0");
+ if (IS_ERR(fpc->sys_clk)) {
+ ret = PTR_ERR(fpc->sys_clk);
+ dev_err(fpc->chip.dev,
+ "failed to get \"ftm0\" clock %d\n", ret);
+ return ret;
+ }
+
+ fpc->counter_clk = devm_clk_get(fpc->chip.dev, "ftm0_counter");
+ if (IS_ERR(fpc->counter_clk)) {
+ ret = PTR_ERR(fpc->counter_clk);
+ dev_err(fpc->chip.dev,
+ "failed to get \"ftm0_counter\" clock %d\n",
+ ret);
+ return ret;
+ }
+
+ ret = of_parse_phandle_with_args(np, "clocks", "#clock-cells", 1,
+ &clkspec);
+ if (ret)
+ return ret;
+
+ fpc->counter_clk_select = clkspec.args[0];
+
+ return fsl_pwm_calculate_ps(fpc);
+}
+
+static int fsl_pwm_probe(struct platform_device *pdev)
+{
+ int ret = 0;
+ struct fsl_pwm_chip *fpc;
+ struct resource *res;
+
+ fpc = devm_kzalloc(&pdev->dev, sizeof(*fpc), GFP_KERNEL);
+ if (!fpc)
+ return -ENOMEM;
+
+ fpc->chip.dev = &pdev->dev;
+ fpc->counter_clk_enable = 0;
+
+ ret = fsl_pwm_parse_clk_ps(fpc);
+ if (ret < 0)
+ return ret;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ fpc->base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(fpc->base)) {
+ ret = PTR_ERR(fpc->base);
+ return ret;
+ }
+
+ 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 = FTM_MAX_CHANNEL;
+ 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 0;
+}
+
+static int fsl_pwm_remove(struct platform_device *pdev)
+{
+ struct fsl_pwm_chip *fpc;
+
+ 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",
+ .owner = THIS_MODULE,
+ .of_match_table = of_match_ptr(fsl_pwm_dt_ids),
+ },
+ .probe = fsl_pwm_probe,
+ .remove = fsl_pwm_remove,
+};
+module_platform_driver(fsl_pwm_driver);
+
+MODULE_DESCRIPTION("Freescale FTM PWM Driver");
+MODULE_AUTHOR("Xiubo Li <Li.Xiubo@freescale.com>");
+MODULE_LICENSE("GPL");
--
1.8.4



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