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authorLinus Torvalds <torvalds@linux-foundation.org>2017-07-13 21:49:52 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2017-07-13 21:49:52 +0300
commit38f7d2da4e39d454f2cb3e7c1ae35afde3d61123 (patch)
tree159ae37207d3fa86cf8f8c06f93f7483e0fdc976
parentdc087d1ef1485363c21b8d781869eb8076342adf (diff)
parent5ec8c48a6235175f7ff59ed1acbe91d4d0398026 (diff)
downloadlinux-38f7d2da4e39d454f2cb3e7c1ae35afde3d61123.tar.xz
Merge tag 'pwm/for-4.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm
Pull pwm updates from Thierry Reding: "This release cycle's changes include mostly updates and cleanups to existing drivers along with a few cleanups to the core, documentation and device tree bindings" * tag 'pwm/for-4.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm: pwm: cros-ec: Fix transposed param settings pwm: meson: Improve PWM calculation precision dt-bindings: pwm: meson: Add compatible for gxbb ao PWMs pwm: meson: Add compatible for the gxbb ao PWMs pwm: sun4i: Drop legacy callbacks pwm: sun4i: Switch to atomic PWM pwm: sun4i: Improve hardware read out pwm: hibvt: Constify hibvt_pwm_ops pwm: Silently error out on EPROBE_DEFER pwm: Standardize document format pwm: bfin: Remove unneeded error message dt-bindings: pwm: Update STM32 timers clock names dt-bindings: pwm: Add R-Car M3-W device tree bindings pwm: tegra: Set maximum pwm clock source per SoC tapeout
-rw-r--r--Documentation/devicetree/bindings/pwm/pwm-meson.txt4
-rw-r--r--Documentation/devicetree/bindings/pwm/pwm-stm32.txt2
-rw-r--r--Documentation/devicetree/bindings/pwm/renesas,pwm-rcar.txt1
-rw-r--r--Documentation/pwm.txt46
-rw-r--r--drivers/pwm/core.c4
-rw-r--r--drivers/pwm/pwm-bfin.c4
-rw-r--r--drivers/pwm/pwm-cros-ec.c4
-rw-r--r--drivers/pwm/pwm-hibvt.c2
-rw-r--r--drivers/pwm/pwm-meson.c48
-rw-r--r--drivers/pwm/pwm-sun4i.c263
-rw-r--r--drivers/pwm/pwm-tegra.c18
11 files changed, 244 insertions, 152 deletions
diff --git a/Documentation/devicetree/bindings/pwm/pwm-meson.txt b/Documentation/devicetree/bindings/pwm/pwm-meson.txt
index 5376a4468cb6..5b07bebbf6f7 100644
--- a/Documentation/devicetree/bindings/pwm/pwm-meson.txt
+++ b/Documentation/devicetree/bindings/pwm/pwm-meson.txt
@@ -2,7 +2,9 @@ Amlogic Meson PWM Controller
============================
Required properties:
-- compatible: Shall contain "amlogic,meson8b-pwm" or "amlogic,meson-gxbb-pwm".
+- compatible: Shall contain "amlogic,meson8b-pwm"
+ or "amlogic,meson-gxbb-pwm"
+ or "amlogic,meson-gxbb-ao-pwm"
- #pwm-cells: Should be 3. See pwm.txt in this directory for a description of
the cells format.
diff --git a/Documentation/devicetree/bindings/pwm/pwm-stm32.txt b/Documentation/devicetree/bindings/pwm/pwm-stm32.txt
index 6dd040363e5e..3e6d55018d7a 100644
--- a/Documentation/devicetree/bindings/pwm/pwm-stm32.txt
+++ b/Documentation/devicetree/bindings/pwm/pwm-stm32.txt
@@ -24,7 +24,7 @@ Example:
compatible = "st,stm32-timers";
reg = <0x40010000 0x400>;
clocks = <&rcc 0 160>;
- clock-names = "clk_int";
+ clock-names = "int";
pwm {
compatible = "st,stm32-pwm";
diff --git a/Documentation/devicetree/bindings/pwm/renesas,pwm-rcar.txt b/Documentation/devicetree/bindings/pwm/renesas,pwm-rcar.txt
index d6de64335022..7e94b802395d 100644
--- a/Documentation/devicetree/bindings/pwm/renesas,pwm-rcar.txt
+++ b/Documentation/devicetree/bindings/pwm/renesas,pwm-rcar.txt
@@ -8,6 +8,7 @@ Required Properties:
- "renesas,pwm-r8a7791": for R-Car M2-W
- "renesas,pwm-r8a7794": for R-Car E2
- "renesas,pwm-r8a7795": for R-Car H3
+ - "renesas,pwm-r8a7796": for R-Car M3-W
- reg: base address and length of the registers block for the PWM.
- #pwm-cells: should be 2. See pwm.txt in this directory for a description of
the cells format.
diff --git a/Documentation/pwm.txt b/Documentation/pwm.txt
index 789b27c6ec99..8fbf0aa3ba2d 100644
--- a/Documentation/pwm.txt
+++ b/Documentation/pwm.txt
@@ -1,4 +1,6 @@
+======================================
Pulse Width Modulation (PWM) interface
+======================================
This provides an overview about the Linux PWM interface
@@ -16,7 +18,7 @@ Users of the legacy PWM API use unique IDs to refer to PWM devices.
Instead of referring to a PWM device via its unique ID, board setup code
should instead register a static mapping that can be used to match PWM
-consumers to providers, as given in the following example:
+consumers to providers, as given in the following example::
static struct pwm_lookup board_pwm_lookup[] = {
PWM_LOOKUP("tegra-pwm", 0, "pwm-backlight", NULL,
@@ -40,9 +42,9 @@ New users should use the pwm_get() function and pass to it the consumer
device or a consumer name. pwm_put() is used to free the PWM device. Managed
variants of these functions, devm_pwm_get() and devm_pwm_put(), also exist.
-After being requested, a PWM has to be configured using:
+After being requested, a PWM has to be configured using::
-int pwm_apply_state(struct pwm_device *pwm, struct pwm_state *state);
+ int pwm_apply_state(struct pwm_device *pwm, struct pwm_state *state);
This API controls both the PWM period/duty_cycle config and the
enable/disable state.
@@ -72,11 +74,14 @@ interface is provided to use the PWMs from userspace. It is exposed at
pwmchipN, where N is the base of the PWM chip. Inside the directory you
will find:
-npwm - The number of PWM channels this chip supports (read-only).
+ npwm
+ The number of PWM channels this chip supports (read-only).
-export - Exports a PWM channel for use with sysfs (write-only).
+ export
+ Exports a PWM channel for use with sysfs (write-only).
-unexport - Unexports a PWM channel from sysfs (write-only).
+ unexport
+ Unexports a PWM channel from sysfs (write-only).
The PWM channels are numbered using a per-chip index from 0 to npwm-1.
@@ -84,21 +89,26 @@ When a PWM channel is exported a pwmX directory will be created in the
pwmchipN directory it is associated with, where X is the number of the
channel that was exported. The following properties will then be available:
-period - The total period of the PWM signal (read/write).
- Value is in nanoseconds and is the sum of the active and inactive
- time of the PWM.
+ period
+ The total period of the PWM signal (read/write).
+ Value is in nanoseconds and is the sum of the active and inactive
+ time of the PWM.
-duty_cycle - The active time of the PWM signal (read/write).
- Value is in nanoseconds and must be less than the period.
+ duty_cycle
+ The active time of the PWM signal (read/write).
+ Value is in nanoseconds and must be less than the period.
-polarity - Changes the polarity of the PWM signal (read/write).
- Writes to this property only work if the PWM chip supports changing
- the polarity. The polarity can only be changed if the PWM is not
- enabled. Value is the string "normal" or "inversed".
+ polarity
+ Changes the polarity of the PWM signal (read/write).
+ Writes to this property only work if the PWM chip supports changing
+ the polarity. The polarity can only be changed if the PWM is not
+ enabled. Value is the string "normal" or "inversed".
-enable - Enable/disable the PWM signal (read/write).
- 0 - disabled
- 1 - enabled
+ enable
+ Enable/disable the PWM signal (read/write).
+
+ - 0 - disabled
+ - 1 - enabled
Implementing a PWM driver
-------------------------
diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c
index a0860b30bd93..1581f6ab1b1f 100644
--- a/drivers/pwm/core.c
+++ b/drivers/pwm/core.c
@@ -678,7 +678,9 @@ struct pwm_device *of_pwm_get(struct device_node *np, const char *con_id)
pc = of_node_to_pwmchip(args.np);
if (IS_ERR(pc)) {
- pr_err("%s(): PWM chip not found\n", __func__);
+ if (PTR_ERR(pc) != -EPROBE_DEFER)
+ pr_err("%s(): PWM chip not found\n", __func__);
+
pwm = ERR_CAST(pc);
goto put;
}
diff --git a/drivers/pwm/pwm-bfin.c b/drivers/pwm/pwm-bfin.c
index d2ed0a2a18e8..a9a88137f2cb 100644
--- a/drivers/pwm/pwm-bfin.c
+++ b/drivers/pwm/pwm-bfin.c
@@ -118,10 +118,8 @@ static int bfin_pwm_probe(struct platform_device *pdev)
int ret;
pwm = devm_kzalloc(&pdev->dev, sizeof(*pwm), GFP_KERNEL);
- if (!pwm) {
- dev_err(&pdev->dev, "failed to allocate memory\n");
+ if (!pwm)
return -ENOMEM;
- }
platform_set_drvdata(pdev, pwm);
diff --git a/drivers/pwm/pwm-cros-ec.c b/drivers/pwm/pwm-cros-ec.c
index f6ca4e8c6253..9c13694eaa24 100644
--- a/drivers/pwm/pwm-cros-ec.c
+++ b/drivers/pwm/pwm-cros-ec.c
@@ -75,8 +75,8 @@ static int __cros_ec_pwm_get_duty(struct cros_ec_device *ec, u8 index,
msg->version = 0;
msg->command = EC_CMD_PWM_GET_DUTY;
- msg->insize = sizeof(*params);
- msg->outsize = sizeof(*resp);
+ msg->insize = sizeof(*resp);
+ msg->outsize = sizeof(*params);
params->pwm_type = EC_PWM_TYPE_GENERIC;
params->index = index;
diff --git a/drivers/pwm/pwm-hibvt.c b/drivers/pwm/pwm-hibvt.c
index d0e8f8542626..8dadc58d6cdf 100644
--- a/drivers/pwm/pwm-hibvt.c
+++ b/drivers/pwm/pwm-hibvt.c
@@ -165,7 +165,7 @@ static int hibvt_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
return 0;
}
-static struct pwm_ops hibvt_pwm_ops = {
+static const struct pwm_ops hibvt_pwm_ops = {
.get_state = hibvt_pwm_get_state,
.apply = hibvt_pwm_apply,
diff --git a/drivers/pwm/pwm-meson.c b/drivers/pwm/pwm-meson.c
index 045ef9fa6fe3..cb845edfe2b4 100644
--- a/drivers/pwm/pwm-meson.c
+++ b/drivers/pwm/pwm-meson.c
@@ -103,6 +103,7 @@ struct meson_pwm_channel {
struct meson_pwm_data {
const char * const *parent_names;
+ unsigned int num_parents;
};
struct meson_pwm {
@@ -162,7 +163,8 @@ static int meson_pwm_calc(struct meson_pwm *meson,
unsigned int duty, unsigned int period)
{
unsigned int pre_div, cnt, duty_cnt;
- unsigned long fin_freq = -1, fin_ns;
+ unsigned long fin_freq = -1;
+ u64 fin_ps;
if (~(meson->inverter_mask >> id) & 0x1)
duty = period - duty;
@@ -178,13 +180,15 @@ static int meson_pwm_calc(struct meson_pwm *meson,
}
dev_dbg(meson->chip.dev, "fin_freq: %lu Hz\n", fin_freq);
- fin_ns = NSEC_PER_SEC / fin_freq;
+ fin_ps = (u64)NSEC_PER_SEC * 1000;
+ do_div(fin_ps, fin_freq);
/* Calc pre_div with the period */
for (pre_div = 0; pre_div < MISC_CLK_DIV_MASK; pre_div++) {
- cnt = DIV_ROUND_CLOSEST(period, fin_ns * (pre_div + 1));
- dev_dbg(meson->chip.dev, "fin_ns=%lu pre_div=%u cnt=%u\n",
- fin_ns, pre_div, cnt);
+ cnt = DIV_ROUND_CLOSEST_ULL((u64)period * 1000,
+ fin_ps * (pre_div + 1));
+ dev_dbg(meson->chip.dev, "fin_ps=%llu pre_div=%u cnt=%u\n",
+ fin_ps, pre_div, cnt);
if (cnt <= 0xffff)
break;
}
@@ -207,7 +211,8 @@ static int meson_pwm_calc(struct meson_pwm *meson,
channel->lo = cnt;
} else {
/* Then check is we can have the duty with the same pre_div */
- duty_cnt = DIV_ROUND_CLOSEST(duty, fin_ns * (pre_div + 1));
+ duty_cnt = DIV_ROUND_CLOSEST_ULL((u64)duty * 1000,
+ fin_ps * (pre_div + 1));
if (duty_cnt > 0xffff) {
dev_err(meson->chip.dev, "unable to get duty cycle\n");
return -EINVAL;
@@ -381,6 +386,7 @@ static const char * const pwm_meson8b_parent_names[] = {
static const struct meson_pwm_data pwm_meson8b_data = {
.parent_names = pwm_meson8b_parent_names,
+ .num_parents = ARRAY_SIZE(pwm_meson8b_parent_names),
};
static const char * const pwm_gxbb_parent_names[] = {
@@ -389,11 +395,35 @@ static const char * const pwm_gxbb_parent_names[] = {
static const struct meson_pwm_data pwm_gxbb_data = {
.parent_names = pwm_gxbb_parent_names,
+ .num_parents = ARRAY_SIZE(pwm_gxbb_parent_names),
+};
+
+/*
+ * Only the 2 first inputs of the GXBB AO PWMs are valid
+ * The last 2 are grounded
+ */
+static const char * const pwm_gxbb_ao_parent_names[] = {
+ "xtal", "clk81"
+};
+
+static const struct meson_pwm_data pwm_gxbb_ao_data = {
+ .parent_names = pwm_gxbb_ao_parent_names,
+ .num_parents = ARRAY_SIZE(pwm_gxbb_ao_parent_names),
};
static const struct of_device_id meson_pwm_matches[] = {
- { .compatible = "amlogic,meson8b-pwm", .data = &pwm_meson8b_data },
- { .compatible = "amlogic,meson-gxbb-pwm", .data = &pwm_gxbb_data },
+ {
+ .compatible = "amlogic,meson8b-pwm",
+ .data = &pwm_meson8b_data
+ },
+ {
+ .compatible = "amlogic,meson-gxbb-pwm",
+ .data = &pwm_gxbb_data
+ },
+ {
+ .compatible = "amlogic,meson-gxbb-ao-pwm",
+ .data = &pwm_gxbb_ao_data
+ },
{},
};
MODULE_DEVICE_TABLE(of, meson_pwm_matches);
@@ -417,7 +447,7 @@ static int meson_pwm_init_channels(struct meson_pwm *meson,
init.ops = &clk_mux_ops;
init.flags = CLK_IS_BASIC;
init.parent_names = meson->data->parent_names;
- init.num_parents = 1 << MISC_CLK_SEL_WIDTH;
+ init.num_parents = meson->data->num_parents;
channel->mux.reg = meson->base + REG_MISC_AB;
channel->mux.shift = mux_reg_shifts[i];
diff --git a/drivers/pwm/pwm-sun4i.c b/drivers/pwm/pwm-sun4i.c
index 1284ffa05921..6d23f1d1c9b7 100644
--- a/drivers/pwm/pwm-sun4i.c
+++ b/drivers/pwm/pwm-sun4i.c
@@ -8,8 +8,10 @@
#include <linux/bitops.h>
#include <linux/clk.h>
+#include <linux/delay.h>
#include <linux/err.h>
#include <linux/io.h>
+#include <linux/jiffies.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
@@ -44,6 +46,10 @@
#define PWM_DTY_MASK GENMASK(15, 0)
+#define PWM_REG_PRD(reg) ((((reg) >> 16) & PWM_PRD_MASK) + 1)
+#define PWM_REG_DTY(reg) ((reg) & PWM_DTY_MASK)
+#define PWM_REG_PRESCAL(reg, chan) (((reg) >> ((chan) * PWMCH_OFFSET)) & PWM_PRESCAL_MASK)
+
#define BIT_CH(bit, chan) ((bit) << ((chan) * PWMCH_OFFSET))
static const u32 prescaler_table[] = {
@@ -77,6 +83,8 @@ struct sun4i_pwm_chip {
void __iomem *base;
spinlock_t ctrl_lock;
const struct sun4i_pwm_data *data;
+ unsigned long next_period[2];
+ bool needs_delay[2];
};
static inline struct sun4i_pwm_chip *to_sun4i_pwm_chip(struct pwm_chip *chip)
@@ -96,26 +104,65 @@ static inline void sun4i_pwm_writel(struct sun4i_pwm_chip *chip,
writel(val, chip->base + offset);
}
-static int sun4i_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
- int duty_ns, int period_ns)
+static void sun4i_pwm_get_state(struct pwm_chip *chip,
+ struct pwm_device *pwm,
+ struct pwm_state *state)
{
struct sun4i_pwm_chip *sun4i_pwm = to_sun4i_pwm_chip(chip);
- u32 prd, dty, val, clk_gate;
+ u64 clk_rate, tmp;
+ u32 val;
+ unsigned int prescaler;
+
+ clk_rate = clk_get_rate(sun4i_pwm->clk);
+
+ val = sun4i_pwm_readl(sun4i_pwm, PWM_CTRL_REG);
+
+ if ((val == PWM_PRESCAL_MASK) && sun4i_pwm->data->has_prescaler_bypass)
+ prescaler = 1;
+ else
+ prescaler = prescaler_table[PWM_REG_PRESCAL(val, pwm->hwpwm)];
+
+ if (prescaler == 0)
+ return;
+
+ if (val & BIT_CH(PWM_ACT_STATE, pwm->hwpwm))
+ state->polarity = PWM_POLARITY_NORMAL;
+ else
+ state->polarity = PWM_POLARITY_INVERSED;
+
+ if (val & BIT_CH(PWM_CLK_GATING | PWM_EN, pwm->hwpwm))
+ state->enabled = true;
+ else
+ state->enabled = false;
+
+ val = sun4i_pwm_readl(sun4i_pwm, PWM_CH_PRD(pwm->hwpwm));
+
+ tmp = prescaler * NSEC_PER_SEC * PWM_REG_DTY(val);
+ state->duty_cycle = DIV_ROUND_CLOSEST_ULL(tmp, clk_rate);
+
+ tmp = prescaler * NSEC_PER_SEC * PWM_REG_PRD(val);
+ state->period = DIV_ROUND_CLOSEST_ULL(tmp, clk_rate);
+}
+
+static int sun4i_pwm_calculate(struct sun4i_pwm_chip *sun4i_pwm,
+ struct pwm_state *state,
+ u32 *dty, u32 *prd, unsigned int *prsclr)
+{
u64 clk_rate, div = 0;
- unsigned int prescaler = 0;
- int err;
+ unsigned int pval, prescaler = 0;
clk_rate = clk_get_rate(sun4i_pwm->clk);
if (sun4i_pwm->data->has_prescaler_bypass) {
/* First, test without any prescaler when available */
prescaler = PWM_PRESCAL_MASK;
+ pval = 1;
/*
* When not using any prescaler, the clock period in nanoseconds
* is not an integer so round it half up instead of
* truncating to get less surprising values.
*/
- div = clk_rate * period_ns + NSEC_PER_SEC / 2;
+ div = clk_rate * state->period + NSEC_PER_SEC / 2;
do_div(div, NSEC_PER_SEC);
if (div - 1 > PWM_PRD_MASK)
prescaler = 0;
@@ -126,137 +173,141 @@ static int sun4i_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
for (prescaler = 0; prescaler < PWM_PRESCAL_MASK; prescaler++) {
if (!prescaler_table[prescaler])
continue;
+ pval = prescaler_table[prescaler];
div = clk_rate;
- do_div(div, prescaler_table[prescaler]);
- div = div * period_ns;
+ do_div(div, pval);
+ div = div * state->period;
do_div(div, NSEC_PER_SEC);
if (div - 1 <= PWM_PRD_MASK)
break;
}
- if (div - 1 > PWM_PRD_MASK) {
- dev_err(chip->dev, "period exceeds the maximum value\n");
+ if (div - 1 > PWM_PRD_MASK)
return -EINVAL;
- }
- }
-
- prd = div;
- div *= duty_ns;
- do_div(div, period_ns);
- dty = div;
-
- err = clk_prepare_enable(sun4i_pwm->clk);
- if (err) {
- dev_err(chip->dev, "failed to enable PWM clock\n");
- return err;
- }
-
- spin_lock(&sun4i_pwm->ctrl_lock);
- val = sun4i_pwm_readl(sun4i_pwm, PWM_CTRL_REG);
-
- if (sun4i_pwm->data->has_rdy && (val & PWM_RDY(pwm->hwpwm))) {
- spin_unlock(&sun4i_pwm->ctrl_lock);
- clk_disable_unprepare(sun4i_pwm->clk);
- return -EBUSY;
- }
-
- clk_gate = val & BIT_CH(PWM_CLK_GATING, pwm->hwpwm);
- if (clk_gate) {
- val &= ~BIT_CH(PWM_CLK_GATING, pwm->hwpwm);
- sun4i_pwm_writel(sun4i_pwm, val, PWM_CTRL_REG);
}
- val = sun4i_pwm_readl(sun4i_pwm, PWM_CTRL_REG);
- val &= ~BIT_CH(PWM_PRESCAL_MASK, pwm->hwpwm);
- val |= BIT_CH(prescaler, pwm->hwpwm);
- sun4i_pwm_writel(sun4i_pwm, val, PWM_CTRL_REG);
-
- val = (dty & PWM_DTY_MASK) | PWM_PRD(prd);
- sun4i_pwm_writel(sun4i_pwm, val, PWM_CH_PRD(pwm->hwpwm));
+ *prd = div;
+ div *= state->duty_cycle;
+ do_div(div, state->period);
+ *dty = div;
+ *prsclr = prescaler;
- if (clk_gate) {
- val = sun4i_pwm_readl(sun4i_pwm, PWM_CTRL_REG);
- val |= clk_gate;
- sun4i_pwm_writel(sun4i_pwm, val, PWM_CTRL_REG);
- }
+ div = (u64)pval * NSEC_PER_SEC * *prd;
+ state->period = DIV_ROUND_CLOSEST_ULL(div, clk_rate);
- spin_unlock(&sun4i_pwm->ctrl_lock);
- clk_disable_unprepare(sun4i_pwm->clk);
+ div = (u64)pval * NSEC_PER_SEC * *dty;
+ state->duty_cycle = DIV_ROUND_CLOSEST_ULL(div, clk_rate);
return 0;
}
-static int sun4i_pwm_set_polarity(struct pwm_chip *chip, struct pwm_device *pwm,
- enum pwm_polarity polarity)
+static int sun4i_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+ struct pwm_state *state)
{
struct sun4i_pwm_chip *sun4i_pwm = to_sun4i_pwm_chip(chip);
- u32 val;
+ struct pwm_state cstate;
+ u32 ctrl;
int ret;
+ unsigned int delay_us;
+ unsigned long now;
- ret = clk_prepare_enable(sun4i_pwm->clk);
- if (ret) {
- dev_err(chip->dev, "failed to enable PWM clock\n");
- return ret;
+ pwm_get_state(pwm, &cstate);
+
+ if (!cstate.enabled) {
+ ret = clk_prepare_enable(sun4i_pwm->clk);
+ if (ret) {
+ dev_err(chip->dev, "failed to enable PWM clock\n");
+ return ret;
+ }
}
spin_lock(&sun4i_pwm->ctrl_lock);
- val = sun4i_pwm_readl(sun4i_pwm, PWM_CTRL_REG);
+ ctrl = sun4i_pwm_readl(sun4i_pwm, PWM_CTRL_REG);
- if (polarity != PWM_POLARITY_NORMAL)
- val &= ~BIT_CH(PWM_ACT_STATE, pwm->hwpwm);
- else
- val |= BIT_CH(PWM_ACT_STATE, pwm->hwpwm);
+ if ((cstate.period != state->period) ||
+ (cstate.duty_cycle != state->duty_cycle)) {
+ u32 period, duty, val;
+ unsigned int prescaler;
- sun4i_pwm_writel(sun4i_pwm, val, PWM_CTRL_REG);
+ ret = sun4i_pwm_calculate(sun4i_pwm, state,
+ &duty, &period, &prescaler);
+ if (ret) {
+ dev_err(chip->dev, "period exceeds the maximum value\n");
+ spin_unlock(&sun4i_pwm->ctrl_lock);
+ if (!cstate.enabled)
+ clk_disable_unprepare(sun4i_pwm->clk);
+ return ret;
+ }
- spin_unlock(&sun4i_pwm->ctrl_lock);
- clk_disable_unprepare(sun4i_pwm->clk);
+ if (PWM_REG_PRESCAL(ctrl, pwm->hwpwm) != prescaler) {
+ /* Prescaler changed, the clock has to be gated */
+ ctrl &= ~BIT_CH(PWM_CLK_GATING, pwm->hwpwm);
+ sun4i_pwm_writel(sun4i_pwm, ctrl, PWM_CTRL_REG);
- return 0;
-}
+ ctrl &= ~BIT_CH(PWM_PRESCAL_MASK, pwm->hwpwm);
+ ctrl |= BIT_CH(prescaler, pwm->hwpwm);
+ }
-static int sun4i_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
-{
- struct sun4i_pwm_chip *sun4i_pwm = to_sun4i_pwm_chip(chip);
- u32 val;
- int ret;
+ val = (duty & PWM_DTY_MASK) | PWM_PRD(period);
+ sun4i_pwm_writel(sun4i_pwm, val, PWM_CH_PRD(pwm->hwpwm));
+ sun4i_pwm->next_period[pwm->hwpwm] = jiffies +
+ usecs_to_jiffies(cstate.period / 1000 + 1);
+ sun4i_pwm->needs_delay[pwm->hwpwm] = true;
+ }
- ret = clk_prepare_enable(sun4i_pwm->clk);
- if (ret) {
- dev_err(chip->dev, "failed to enable PWM clock\n");
- return ret;
+ if (state->polarity != PWM_POLARITY_NORMAL)
+ ctrl &= ~BIT_CH(PWM_ACT_STATE, pwm->hwpwm);
+ else
+ ctrl |= BIT_CH(PWM_ACT_STATE, pwm->hwpwm);
+
+ ctrl |= BIT_CH(PWM_CLK_GATING, pwm->hwpwm);
+ if (state->enabled) {
+ ctrl |= BIT_CH(PWM_EN, pwm->hwpwm);
+ } else if (!sun4i_pwm->needs_delay[pwm->hwpwm]) {
+ ctrl &= ~BIT_CH(PWM_EN, pwm->hwpwm);
+ ctrl &= ~BIT_CH(PWM_CLK_GATING, pwm->hwpwm);
}
- spin_lock(&sun4i_pwm->ctrl_lock);
- val = sun4i_pwm_readl(sun4i_pwm, PWM_CTRL_REG);
- val |= BIT_CH(PWM_EN, pwm->hwpwm);
- val |= BIT_CH(PWM_CLK_GATING, pwm->hwpwm);
- sun4i_pwm_writel(sun4i_pwm, val, PWM_CTRL_REG);
+ sun4i_pwm_writel(sun4i_pwm, ctrl, PWM_CTRL_REG);
+
spin_unlock(&sun4i_pwm->ctrl_lock);
- return 0;
-}
+ if (state->enabled)
+ return 0;
-static void sun4i_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
-{
- struct sun4i_pwm_chip *sun4i_pwm = to_sun4i_pwm_chip(chip);
- u32 val;
+ if (!sun4i_pwm->needs_delay[pwm->hwpwm]) {
+ clk_disable_unprepare(sun4i_pwm->clk);
+ return 0;
+ }
+
+ /* We need a full period to elapse before disabling the channel. */
+ now = jiffies;
+ if (sun4i_pwm->needs_delay[pwm->hwpwm] &&
+ time_before(now, sun4i_pwm->next_period[pwm->hwpwm])) {
+ delay_us = jiffies_to_usecs(sun4i_pwm->next_period[pwm->hwpwm] -
+ now);
+ if ((delay_us / 500) > MAX_UDELAY_MS)
+ msleep(delay_us / 1000 + 1);
+ else
+ usleep_range(delay_us, delay_us * 2);
+ }
+ sun4i_pwm->needs_delay[pwm->hwpwm] = false;
spin_lock(&sun4i_pwm->ctrl_lock);
- val = sun4i_pwm_readl(sun4i_pwm, PWM_CTRL_REG);
- val &= ~BIT_CH(PWM_EN, pwm->hwpwm);
- val &= ~BIT_CH(PWM_CLK_GATING, pwm->hwpwm);
- sun4i_pwm_writel(sun4i_pwm, val, PWM_CTRL_REG);
+ ctrl = sun4i_pwm_readl(sun4i_pwm, PWM_CTRL_REG);
+ ctrl &= ~BIT_CH(PWM_CLK_GATING, pwm->hwpwm);
+ ctrl &= ~BIT_CH(PWM_EN, pwm->hwpwm);
+ sun4i_pwm_writel(sun4i_pwm, ctrl, PWM_CTRL_REG);
spin_unlock(&sun4i_pwm->ctrl_lock);
clk_disable_unprepare(sun4i_pwm->clk);
+
+ return 0;
}
static const struct pwm_ops sun4i_pwm_ops = {
- .config = sun4i_pwm_config,
- .set_polarity = sun4i_pwm_set_polarity,
- .enable = sun4i_pwm_enable,
- .disable = sun4i_pwm_disable,
+ .apply = sun4i_pwm_apply,
+ .get_state = sun4i_pwm_get_state,
.owner = THIS_MODULE,
};
@@ -316,8 +367,7 @@ static int sun4i_pwm_probe(struct platform_device *pdev)
{
struct sun4i_pwm_chip *pwm;
struct resource *res;
- u32 val;
- int i, ret;
+ int ret;
const struct of_device_id *match;
match = of_match_device(sun4i_pwm_dt_ids, &pdev->dev);
@@ -353,24 +403,7 @@ static int sun4i_pwm_probe(struct platform_device *pdev)
platform_set_drvdata(pdev, pwm);
- ret = clk_prepare_enable(pwm->clk);
- if (ret) {
- dev_err(&pdev->dev, "failed to enable PWM clock\n");
- goto clk_error;
- }
-
- val = sun4i_pwm_readl(pwm, PWM_CTRL_REG);
- for (i = 0; i < pwm->chip.npwm; i++)
- if (!(val & BIT_CH(PWM_ACT_STATE, i)))
- pwm_set_polarity(&pwm->chip.pwms[i],
- PWM_POLARITY_INVERSED);
- clk_disable_unprepare(pwm->clk);
-
return 0;
-
-clk_error:
- pwmchip_remove(&pwm->chip);
- return ret;
}
static int sun4i_pwm_remove(struct platform_device *pdev)
diff --git a/drivers/pwm/pwm-tegra.c b/drivers/pwm/pwm-tegra.c
index 8c6ed556db28..e9b33f09ff09 100644
--- a/drivers/pwm/pwm-tegra.c
+++ b/drivers/pwm/pwm-tegra.c
@@ -41,6 +41,9 @@
struct tegra_pwm_soc {
unsigned int num_channels;
+
+ /* Maximum IP frequency for given SoCs */
+ unsigned long max_frequency;
};
struct tegra_pwm_chip {
@@ -201,7 +204,18 @@ static int tegra_pwm_probe(struct platform_device *pdev)
if (IS_ERR(pwm->clk))
return PTR_ERR(pwm->clk);
- /* Read PWM clock rate from source */
+ /* Set maximum frequency of the IP */
+ ret = clk_set_rate(pwm->clk, pwm->soc->max_frequency);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "Failed to set max frequency: %d\n", ret);
+ return ret;
+ }
+
+ /*
+ * The requested and configured frequency may differ due to
+ * clock register resolutions. Get the configured frequency
+ * so that PWM period can be calculated more accurately.
+ */
pwm->clk_rate = clk_get_rate(pwm->clk);
pwm->rst = devm_reset_control_get(&pdev->dev, "pwm");
@@ -273,10 +287,12 @@ static int tegra_pwm_resume(struct device *dev)
static const struct tegra_pwm_soc tegra20_pwm_soc = {
.num_channels = 4,
+ .max_frequency = 48000000UL,
};
static const struct tegra_pwm_soc tegra186_pwm_soc = {
.num_channels = 1,
+ .max_frequency = 102000000UL,
};
static const struct of_device_id tegra_pwm_of_match[] = {