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path: root/drivers/pwm/pwm-imx.c
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Diffstat (limited to 'drivers/pwm/pwm-imx.c')
-rw-r--r--drivers/pwm/pwm-imx.c272
1 files changed, 129 insertions, 143 deletions
diff --git a/drivers/pwm/pwm-imx.c b/drivers/pwm/pwm-imx.c
index d600fd5cd4ba..2ba5c3a398ff 100644
--- a/drivers/pwm/pwm-imx.c
+++ b/drivers/pwm/pwm-imx.c
@@ -38,6 +38,7 @@
#define MX3_PWMCR_DOZEEN (1 << 24)
#define MX3_PWMCR_WAITEN (1 << 23)
#define MX3_PWMCR_DBGEN (1 << 22)
+#define MX3_PWMCR_POUTC (1 << 18)
#define MX3_PWMCR_CLKSRC_IPG_HIGH (2 << 16)
#define MX3_PWMCR_CLKSRC_IPG (1 << 16)
#define MX3_PWMCR_SWR (1 << 3)
@@ -49,15 +50,10 @@
struct imx_chip {
struct clk *clk_per;
- struct clk *clk_ipg;
void __iomem *mmio_base;
struct pwm_chip chip;
-
- int (*config)(struct pwm_chip *chip,
- struct pwm_device *pwm, int duty_ns, int period_ns);
- void (*set_enable)(struct pwm_chip *chip, bool enable);
};
#define to_imx_chip(chip) container_of(chip, struct imx_chip, chip)
@@ -91,176 +87,170 @@ static int imx_pwm_config_v1(struct pwm_chip *chip,
return 0;
}
-static void imx_pwm_set_enable_v1(struct pwm_chip *chip, bool enable)
+static int imx_pwm_enable_v1(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct imx_chip *imx = to_imx_chip(chip);
u32 val;
+ int ret;
- val = readl(imx->mmio_base + MX1_PWMC);
-
- if (enable)
- val |= MX1_PWMC_EN;
- else
- val &= ~MX1_PWMC_EN;
+ ret = clk_prepare_enable(imx->clk_per);
+ if (ret < 0)
+ return ret;
+ val = readl(imx->mmio_base + MX1_PWMC);
+ val |= MX1_PWMC_EN;
writel(val, imx->mmio_base + MX1_PWMC);
-}
-
-static int imx_pwm_config_v2(struct pwm_chip *chip,
- struct pwm_device *pwm, int duty_ns, int period_ns)
-{
- struct imx_chip *imx = to_imx_chip(chip);
- struct device *dev = chip->dev;
- unsigned long long c;
- unsigned long period_cycles, duty_cycles, prescale;
- unsigned int period_ms;
- bool enable = pwm_is_enabled(pwm);
- int wait_count = 0, fifoav;
- u32 cr, sr;
-
- /*
- * i.MX PWMv2 has a 4-word sample FIFO.
- * In order to avoid FIFO overflow issue, we do software reset
- * to clear all sample FIFO if the controller is disabled or
- * wait for a full PWM cycle to get a relinquished FIFO slot
- * when the controller is enabled and the FIFO is fully loaded.
- */
- if (enable) {
- sr = readl(imx->mmio_base + MX3_PWMSR);
- fifoav = sr & MX3_PWMSR_FIFOAV_MASK;
- if (fifoav == MX3_PWMSR_FIFOAV_4WORDS) {
- period_ms = DIV_ROUND_UP(pwm_get_period(pwm),
- NSEC_PER_MSEC);
- msleep(period_ms);
-
- sr = readl(imx->mmio_base + MX3_PWMSR);
- if (fifoav == (sr & MX3_PWMSR_FIFOAV_MASK))
- dev_warn(dev, "there is no free FIFO slot\n");
- }
- } else {
- writel(MX3_PWMCR_SWR, imx->mmio_base + MX3_PWMCR);
- do {
- usleep_range(200, 1000);
- cr = readl(imx->mmio_base + MX3_PWMCR);
- } while ((cr & MX3_PWMCR_SWR) &&
- (wait_count++ < MX3_PWM_SWR_LOOP));
-
- if (cr & MX3_PWMCR_SWR)
- dev_warn(dev, "software reset timeout\n");
- }
-
- c = clk_get_rate(imx->clk_per);
- c = c * period_ns;
- do_div(c, 1000000000);
- period_cycles = c;
-
- prescale = period_cycles / 0x10000 + 1;
-
- period_cycles /= prescale;
- c = (unsigned long long)period_cycles * duty_ns;
- do_div(c, period_ns);
- duty_cycles = c;
-
- /*
- * according to imx pwm RM, the real period value should be
- * PERIOD value in PWMPR plus 2.
- */
- if (period_cycles > 2)
- period_cycles -= 2;
- else
- period_cycles = 0;
-
- writel(duty_cycles, imx->mmio_base + MX3_PWMSAR);
- writel(period_cycles, imx->mmio_base + MX3_PWMPR);
-
- cr = MX3_PWMCR_PRESCALER(prescale) |
- MX3_PWMCR_DOZEEN | MX3_PWMCR_WAITEN |
- MX3_PWMCR_DBGEN | MX3_PWMCR_CLKSRC_IPG_HIGH;
-
- if (enable)
- cr |= MX3_PWMCR_EN;
-
- writel(cr, imx->mmio_base + MX3_PWMCR);
return 0;
}
-static void imx_pwm_set_enable_v2(struct pwm_chip *chip, bool enable)
+static void imx_pwm_disable_v1(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct imx_chip *imx = to_imx_chip(chip);
u32 val;
- val = readl(imx->mmio_base + MX3_PWMCR);
-
- if (enable)
- val |= MX3_PWMCR_EN;
- else
- val &= ~MX3_PWMCR_EN;
+ val = readl(imx->mmio_base + MX1_PWMC);
+ val &= ~MX1_PWMC_EN;
+ writel(val, imx->mmio_base + MX1_PWMC);
- writel(val, imx->mmio_base + MX3_PWMCR);
+ clk_disable_unprepare(imx->clk_per);
}
-static int imx_pwm_config(struct pwm_chip *chip,
- struct pwm_device *pwm, int duty_ns, int period_ns)
+static void imx_pwm_sw_reset(struct pwm_chip *chip)
{
struct imx_chip *imx = to_imx_chip(chip);
- int ret;
-
- ret = clk_prepare_enable(imx->clk_ipg);
- if (ret)
- return ret;
+ struct device *dev = chip->dev;
+ int wait_count = 0;
+ u32 cr;
+
+ writel(MX3_PWMCR_SWR, imx->mmio_base + MX3_PWMCR);
+ do {
+ usleep_range(200, 1000);
+ cr = readl(imx->mmio_base + MX3_PWMCR);
+ } while ((cr & MX3_PWMCR_SWR) &&
+ (wait_count++ < MX3_PWM_SWR_LOOP));
+
+ if (cr & MX3_PWMCR_SWR)
+ dev_warn(dev, "software reset timeout\n");
+}
- ret = imx->config(chip, pwm, duty_ns, period_ns);
+static void imx_pwm_wait_fifo_slot(struct pwm_chip *chip,
+ struct pwm_device *pwm)
+{
+ struct imx_chip *imx = to_imx_chip(chip);
+ struct device *dev = chip->dev;
+ unsigned int period_ms;
+ int fifoav;
+ u32 sr;
- clk_disable_unprepare(imx->clk_ipg);
+ sr = readl(imx->mmio_base + MX3_PWMSR);
+ fifoav = sr & MX3_PWMSR_FIFOAV_MASK;
+ if (fifoav == MX3_PWMSR_FIFOAV_4WORDS) {
+ period_ms = DIV_ROUND_UP(pwm_get_period(pwm),
+ NSEC_PER_MSEC);
+ msleep(period_ms);
- return ret;
+ sr = readl(imx->mmio_base + MX3_PWMSR);
+ if (fifoav == (sr & MX3_PWMSR_FIFOAV_MASK))
+ dev_warn(dev, "there is no free FIFO slot\n");
+ }
}
-static int imx_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
+static int imx_pwm_apply_v2(struct pwm_chip *chip, struct pwm_device *pwm,
+ struct pwm_state *state)
{
+ unsigned long period_cycles, duty_cycles, prescale;
struct imx_chip *imx = to_imx_chip(chip);
+ struct pwm_state cstate;
+ unsigned long long c;
int ret;
+ u32 cr;
+
+ pwm_get_state(pwm, &cstate);
+
+ if (state->enabled) {
+ c = clk_get_rate(imx->clk_per);
+ c *= state->period;
+
+ do_div(c, 1000000000);
+ period_cycles = c;
+
+ prescale = period_cycles / 0x10000 + 1;
+
+ period_cycles /= prescale;
+ c = (unsigned long long)period_cycles * state->duty_cycle;
+ do_div(c, state->period);
+ duty_cycles = c;
+
+ /*
+ * according to imx pwm RM, the real period value should be
+ * PERIOD value in PWMPR plus 2.
+ */
+ if (period_cycles > 2)
+ period_cycles -= 2;
+ else
+ period_cycles = 0;
+
+ /*
+ * Wait for a free FIFO slot if the PWM is already enabled, and
+ * flush the FIFO if the PWM was disabled and is about to be
+ * enabled.
+ */
+ if (cstate.enabled) {
+ imx_pwm_wait_fifo_slot(chip, pwm);
+ } else {
+ ret = clk_prepare_enable(imx->clk_per);
+ if (ret)
+ return ret;
+
+ imx_pwm_sw_reset(chip);
+ }
- ret = clk_prepare_enable(imx->clk_per);
- if (ret)
- return ret;
+ writel(duty_cycles, imx->mmio_base + MX3_PWMSAR);
+ writel(period_cycles, imx->mmio_base + MX3_PWMPR);
- imx->set_enable(chip, true);
+ cr = MX3_PWMCR_PRESCALER(prescale) |
+ MX3_PWMCR_DOZEEN | MX3_PWMCR_WAITEN |
+ MX3_PWMCR_DBGEN | MX3_PWMCR_CLKSRC_IPG_HIGH |
+ MX3_PWMCR_EN;
- return 0;
-}
+ if (state->polarity == PWM_POLARITY_INVERSED)
+ cr |= MX3_PWMCR_POUTC;
-static void imx_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
-{
- struct imx_chip *imx = to_imx_chip(chip);
+ writel(cr, imx->mmio_base + MX3_PWMCR);
+ } else if (cstate.enabled) {
+ writel(0, imx->mmio_base + MX3_PWMCR);
- imx->set_enable(chip, false);
+ clk_disable_unprepare(imx->clk_per);
+ }
- clk_disable_unprepare(imx->clk_per);
+ return 0;
}
-static struct pwm_ops imx_pwm_ops = {
- .enable = imx_pwm_enable,
- .disable = imx_pwm_disable,
- .config = imx_pwm_config,
+static const struct pwm_ops imx_pwm_ops_v1 = {
+ .enable = imx_pwm_enable_v1,
+ .disable = imx_pwm_disable_v1,
+ .config = imx_pwm_config_v1,
+ .owner = THIS_MODULE,
+};
+
+static const struct pwm_ops imx_pwm_ops_v2 = {
+ .apply = imx_pwm_apply_v2,
.owner = THIS_MODULE,
};
struct imx_pwm_data {
- int (*config)(struct pwm_chip *chip,
- struct pwm_device *pwm, int duty_ns, int period_ns);
- void (*set_enable)(struct pwm_chip *chip, bool enable);
+ bool polarity_supported;
+ const struct pwm_ops *ops;
};
static struct imx_pwm_data imx_pwm_data_v1 = {
- .config = imx_pwm_config_v1,
- .set_enable = imx_pwm_set_enable_v1,
+ .ops = &imx_pwm_ops_v1,
};
static struct imx_pwm_data imx_pwm_data_v2 = {
- .config = imx_pwm_config_v2,
- .set_enable = imx_pwm_set_enable_v2,
+ .polarity_supported = true,
+ .ops = &imx_pwm_ops_v2,
};
static const struct of_device_id imx_pwm_dt_ids[] = {
@@ -282,6 +272,8 @@ static int imx_pwm_probe(struct platform_device *pdev)
if (!of_id)
return -ENODEV;
+ data = of_id->data;
+
imx = devm_kzalloc(&pdev->dev, sizeof(*imx), GFP_KERNEL);
if (imx == NULL)
return -ENOMEM;
@@ -293,28 +285,22 @@ static int imx_pwm_probe(struct platform_device *pdev)
return PTR_ERR(imx->clk_per);
}
- imx->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
- if (IS_ERR(imx->clk_ipg)) {
- dev_err(&pdev->dev, "getting ipg clock failed with %ld\n",
- PTR_ERR(imx->clk_ipg));
- return PTR_ERR(imx->clk_ipg);
- }
-
- imx->chip.ops = &imx_pwm_ops;
+ imx->chip.ops = data->ops;
imx->chip.dev = &pdev->dev;
imx->chip.base = -1;
imx->chip.npwm = 1;
- imx->chip.can_sleep = true;
+
+ if (data->polarity_supported) {
+ dev_dbg(&pdev->dev, "PWM supports output inversion\n");
+ imx->chip.of_xlate = of_pwm_xlate_with_flags;
+ imx->chip.of_pwm_n_cells = 3;
+ }
r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
imx->mmio_base = devm_ioremap_resource(&pdev->dev, r);
if (IS_ERR(imx->mmio_base))
return PTR_ERR(imx->mmio_base);
- data = of_id->data;
- imx->config = data->config;
- imx->set_enable = data->set_enable;
-
ret = pwmchip_add(&imx->chip);
if (ret < 0)
return ret;
generated by cgit v1.2.3-55-g7522 (git 2.39.0) at 2024-11-19 23:05:57 +0100