linux/drivers/counter/stm32-timer-cnt.c
Fabrice Gasnier 1aed15275b counter: stm32-timer-cnt: add support for capture events
Add support for capture events. Captured counter value for each channel
can be retrieved through CCRx register.
STM32 timers can have up to 4 capture channels (on input channel 1 to
channel 4), hence need to check the number of channels before reading
the capture data.
The capture configuration is hard-coded to capture signals on both edges
(non-inverted). Interrupts are used to report events independently for
each channel.

Reviewed-by: William Breathitt Gray <william.gray@linaro.org>
Acked-by: Lee Jones <lee@kernel.org>
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Link: https://lore.kernel.org/r/20240307133306.383045-11-fabrice.gasnier@foss.st.com
Signed-off-by: William Breathitt Gray <william.gray@linaro.org>
2024-04-02 13:10:34 -04:00

857 lines
23 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* STM32 Timer Encoder and Counter driver
*
* Copyright (C) STMicroelectronics 2018
*
* Author: Benjamin Gaignard <benjamin.gaignard@st.com>
*
*/
#include <linux/counter.h>
#include <linux/interrupt.h>
#include <linux/mfd/stm32-timers.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/pinctrl/consumer.h>
#include <linux/platform_device.h>
#include <linux/types.h>
#define TIM_CCMR_CCXS (BIT(8) | BIT(0))
#define TIM_CCMR_MASK (TIM_CCMR_CC1S | TIM_CCMR_CC2S | \
TIM_CCMR_IC1F | TIM_CCMR_IC2F)
#define TIM_CCER_MASK (TIM_CCER_CC1P | TIM_CCER_CC1NP | \
TIM_CCER_CC2P | TIM_CCER_CC2NP)
#define STM32_CH1_SIG 0
#define STM32_CH2_SIG 1
#define STM32_CLOCK_SIG 2
#define STM32_CH3_SIG 3
#define STM32_CH4_SIG 4
struct stm32_timer_regs {
u32 cr1;
u32 cnt;
u32 smcr;
u32 arr;
};
struct stm32_timer_cnt {
struct regmap *regmap;
struct clk *clk;
u32 max_arr;
bool enabled;
struct stm32_timer_regs bak;
bool has_encoder;
unsigned int nchannels;
unsigned int nr_irqs;
spinlock_t lock; /* protects nb_ovf */
u64 nb_ovf;
};
static const enum counter_function stm32_count_functions[] = {
COUNTER_FUNCTION_INCREASE,
COUNTER_FUNCTION_QUADRATURE_X2_A,
COUNTER_FUNCTION_QUADRATURE_X2_B,
COUNTER_FUNCTION_QUADRATURE_X4,
};
static int stm32_count_read(struct counter_device *counter,
struct counter_count *count, u64 *val)
{
struct stm32_timer_cnt *const priv = counter_priv(counter);
u32 cnt;
regmap_read(priv->regmap, TIM_CNT, &cnt);
*val = cnt;
return 0;
}
static int stm32_count_write(struct counter_device *counter,
struct counter_count *count, const u64 val)
{
struct stm32_timer_cnt *const priv = counter_priv(counter);
u32 ceiling;
regmap_read(priv->regmap, TIM_ARR, &ceiling);
if (val > ceiling)
return -EINVAL;
return regmap_write(priv->regmap, TIM_CNT, val);
}
static int stm32_count_function_read(struct counter_device *counter,
struct counter_count *count,
enum counter_function *function)
{
struct stm32_timer_cnt *const priv = counter_priv(counter);
u32 smcr;
regmap_read(priv->regmap, TIM_SMCR, &smcr);
switch (smcr & TIM_SMCR_SMS) {
case TIM_SMCR_SMS_SLAVE_MODE_DISABLED:
*function = COUNTER_FUNCTION_INCREASE;
return 0;
case TIM_SMCR_SMS_ENCODER_MODE_1:
*function = COUNTER_FUNCTION_QUADRATURE_X2_A;
return 0;
case TIM_SMCR_SMS_ENCODER_MODE_2:
*function = COUNTER_FUNCTION_QUADRATURE_X2_B;
return 0;
case TIM_SMCR_SMS_ENCODER_MODE_3:
*function = COUNTER_FUNCTION_QUADRATURE_X4;
return 0;
default:
return -EINVAL;
}
}
static int stm32_count_function_write(struct counter_device *counter,
struct counter_count *count,
enum counter_function function)
{
struct stm32_timer_cnt *const priv = counter_priv(counter);
u32 cr1, sms;
switch (function) {
case COUNTER_FUNCTION_INCREASE:
sms = TIM_SMCR_SMS_SLAVE_MODE_DISABLED;
break;
case COUNTER_FUNCTION_QUADRATURE_X2_A:
if (!priv->has_encoder)
return -EOPNOTSUPP;
sms = TIM_SMCR_SMS_ENCODER_MODE_1;
break;
case COUNTER_FUNCTION_QUADRATURE_X2_B:
if (!priv->has_encoder)
return -EOPNOTSUPP;
sms = TIM_SMCR_SMS_ENCODER_MODE_2;
break;
case COUNTER_FUNCTION_QUADRATURE_X4:
if (!priv->has_encoder)
return -EOPNOTSUPP;
sms = TIM_SMCR_SMS_ENCODER_MODE_3;
break;
default:
return -EINVAL;
}
/* Store enable status */
regmap_read(priv->regmap, TIM_CR1, &cr1);
regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN, 0);
regmap_update_bits(priv->regmap, TIM_SMCR, TIM_SMCR_SMS, sms);
/* Make sure that registers are updated */
regmap_update_bits(priv->regmap, TIM_EGR, TIM_EGR_UG, TIM_EGR_UG);
/* Restore the enable status */
regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN, cr1);
return 0;
}
static int stm32_count_direction_read(struct counter_device *counter,
struct counter_count *count,
enum counter_count_direction *direction)
{
struct stm32_timer_cnt *const priv = counter_priv(counter);
u32 cr1;
regmap_read(priv->regmap, TIM_CR1, &cr1);
*direction = (cr1 & TIM_CR1_DIR) ? COUNTER_COUNT_DIRECTION_BACKWARD :
COUNTER_COUNT_DIRECTION_FORWARD;
return 0;
}
static int stm32_count_ceiling_read(struct counter_device *counter,
struct counter_count *count, u64 *ceiling)
{
struct stm32_timer_cnt *const priv = counter_priv(counter);
u32 arr;
regmap_read(priv->regmap, TIM_ARR, &arr);
*ceiling = arr;
return 0;
}
static int stm32_count_ceiling_write(struct counter_device *counter,
struct counter_count *count, u64 ceiling)
{
struct stm32_timer_cnt *const priv = counter_priv(counter);
if (ceiling > priv->max_arr)
return -ERANGE;
/* TIMx_ARR register shouldn't be buffered (ARPE=0) */
regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_ARPE, 0);
regmap_write(priv->regmap, TIM_ARR, ceiling);
return 0;
}
static int stm32_count_enable_read(struct counter_device *counter,
struct counter_count *count, u8 *enable)
{
struct stm32_timer_cnt *const priv = counter_priv(counter);
u32 cr1;
regmap_read(priv->regmap, TIM_CR1, &cr1);
*enable = cr1 & TIM_CR1_CEN;
return 0;
}
static int stm32_count_enable_write(struct counter_device *counter,
struct counter_count *count, u8 enable)
{
struct stm32_timer_cnt *const priv = counter_priv(counter);
u32 cr1;
if (enable) {
regmap_read(priv->regmap, TIM_CR1, &cr1);
if (!(cr1 & TIM_CR1_CEN))
clk_enable(priv->clk);
regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN,
TIM_CR1_CEN);
} else {
regmap_read(priv->regmap, TIM_CR1, &cr1);
regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN, 0);
if (cr1 & TIM_CR1_CEN)
clk_disable(priv->clk);
}
/* Keep enabled state to properly handle low power states */
priv->enabled = enable;
return 0;
}
static int stm32_count_prescaler_read(struct counter_device *counter,
struct counter_count *count, u64 *prescaler)
{
struct stm32_timer_cnt *const priv = counter_priv(counter);
u32 psc;
regmap_read(priv->regmap, TIM_PSC, &psc);
*prescaler = psc + 1;
return 0;
}
static int stm32_count_prescaler_write(struct counter_device *counter,
struct counter_count *count, u64 prescaler)
{
struct stm32_timer_cnt *const priv = counter_priv(counter);
u32 psc;
if (!prescaler || prescaler > MAX_TIM_PSC + 1)
return -ERANGE;
psc = prescaler - 1;
return regmap_write(priv->regmap, TIM_PSC, psc);
}
static int stm32_count_cap_read(struct counter_device *counter,
struct counter_count *count,
size_t ch, u64 *cap)
{
struct stm32_timer_cnt *const priv = counter_priv(counter);
u32 ccrx;
if (ch >= priv->nchannels)
return -EOPNOTSUPP;
switch (ch) {
case 0:
regmap_read(priv->regmap, TIM_CCR1, &ccrx);
break;
case 1:
regmap_read(priv->regmap, TIM_CCR2, &ccrx);
break;
case 2:
regmap_read(priv->regmap, TIM_CCR3, &ccrx);
break;
case 3:
regmap_read(priv->regmap, TIM_CCR4, &ccrx);
break;
default:
return -EINVAL;
}
dev_dbg(counter->parent, "CCR%zu: 0x%08x\n", ch + 1, ccrx);
*cap = ccrx;
return 0;
}
static int stm32_count_nb_ovf_read(struct counter_device *counter,
struct counter_count *count, u64 *val)
{
struct stm32_timer_cnt *const priv = counter_priv(counter);
unsigned long irqflags;
spin_lock_irqsave(&priv->lock, irqflags);
*val = priv->nb_ovf;
spin_unlock_irqrestore(&priv->lock, irqflags);
return 0;
}
static int stm32_count_nb_ovf_write(struct counter_device *counter,
struct counter_count *count, u64 val)
{
struct stm32_timer_cnt *const priv = counter_priv(counter);
unsigned long irqflags;
spin_lock_irqsave(&priv->lock, irqflags);
priv->nb_ovf = val;
spin_unlock_irqrestore(&priv->lock, irqflags);
return 0;
}
static DEFINE_COUNTER_ARRAY_CAPTURE(stm32_count_cap_array, 4);
static struct counter_comp stm32_count_ext[] = {
COUNTER_COMP_DIRECTION(stm32_count_direction_read),
COUNTER_COMP_ENABLE(stm32_count_enable_read, stm32_count_enable_write),
COUNTER_COMP_CEILING(stm32_count_ceiling_read,
stm32_count_ceiling_write),
COUNTER_COMP_COUNT_U64("prescaler", stm32_count_prescaler_read,
stm32_count_prescaler_write),
COUNTER_COMP_ARRAY_CAPTURE(stm32_count_cap_read, NULL, stm32_count_cap_array),
COUNTER_COMP_COUNT_U64("num_overflows", stm32_count_nb_ovf_read, stm32_count_nb_ovf_write),
};
static const enum counter_synapse_action stm32_clock_synapse_actions[] = {
COUNTER_SYNAPSE_ACTION_RISING_EDGE,
};
static const enum counter_synapse_action stm32_synapse_actions[] = {
COUNTER_SYNAPSE_ACTION_NONE,
COUNTER_SYNAPSE_ACTION_BOTH_EDGES
};
static int stm32_action_read(struct counter_device *counter,
struct counter_count *count,
struct counter_synapse *synapse,
enum counter_synapse_action *action)
{
enum counter_function function;
int err;
err = stm32_count_function_read(counter, count, &function);
if (err)
return err;
switch (function) {
case COUNTER_FUNCTION_INCREASE:
/* counts on internal clock when CEN=1 */
if (synapse->signal->id == STM32_CLOCK_SIG)
*action = COUNTER_SYNAPSE_ACTION_RISING_EDGE;
else
*action = COUNTER_SYNAPSE_ACTION_NONE;
return 0;
case COUNTER_FUNCTION_QUADRATURE_X2_A:
/* counts up/down on TI1FP1 edge depending on TI2FP2 level */
if (synapse->signal->id == STM32_CH1_SIG)
*action = COUNTER_SYNAPSE_ACTION_BOTH_EDGES;
else
*action = COUNTER_SYNAPSE_ACTION_NONE;
return 0;
case COUNTER_FUNCTION_QUADRATURE_X2_B:
/* counts up/down on TI2FP2 edge depending on TI1FP1 level */
if (synapse->signal->id == STM32_CH2_SIG)
*action = COUNTER_SYNAPSE_ACTION_BOTH_EDGES;
else
*action = COUNTER_SYNAPSE_ACTION_NONE;
return 0;
case COUNTER_FUNCTION_QUADRATURE_X4:
/* counts up/down on both TI1FP1 and TI2FP2 edges */
if (synapse->signal->id == STM32_CH1_SIG || synapse->signal->id == STM32_CH2_SIG)
*action = COUNTER_SYNAPSE_ACTION_BOTH_EDGES;
else
*action = COUNTER_SYNAPSE_ACTION_NONE;
return 0;
default:
return -EINVAL;
}
}
struct stm32_count_cc_regs {
u32 ccmr_reg;
u32 ccmr_mask;
u32 ccmr_bits;
u32 ccer_bits;
};
static const struct stm32_count_cc_regs stm32_cc[] = {
{ TIM_CCMR1, TIM_CCMR_CC1S, TIM_CCMR_CC1S_TI1,
TIM_CCER_CC1E | TIM_CCER_CC1P | TIM_CCER_CC1NP },
{ TIM_CCMR1, TIM_CCMR_CC2S, TIM_CCMR_CC2S_TI2,
TIM_CCER_CC2E | TIM_CCER_CC2P | TIM_CCER_CC2NP },
{ TIM_CCMR2, TIM_CCMR_CC3S, TIM_CCMR_CC3S_TI3,
TIM_CCER_CC3E | TIM_CCER_CC3P | TIM_CCER_CC3NP },
{ TIM_CCMR2, TIM_CCMR_CC4S, TIM_CCMR_CC4S_TI4,
TIM_CCER_CC4E | TIM_CCER_CC4P | TIM_CCER_CC4NP },
};
static int stm32_count_capture_configure(struct counter_device *counter, unsigned int ch,
bool enable)
{
struct stm32_timer_cnt *const priv = counter_priv(counter);
const struct stm32_count_cc_regs *cc;
u32 ccmr, ccer;
if (ch >= ARRAY_SIZE(stm32_cc) || ch >= priv->nchannels) {
dev_err(counter->parent, "invalid ch: %d\n", ch);
return -EINVAL;
}
cc = &stm32_cc[ch];
/*
* configure channel in input capture mode, map channel 1 on TI1, channel2 on TI2...
* Select both edges / non-inverted to trigger a capture.
*/
if (enable) {
/* first clear possibly latched capture flag upon enabling */
if (!regmap_test_bits(priv->regmap, TIM_CCER, cc->ccer_bits))
regmap_write(priv->regmap, TIM_SR, ~TIM_SR_CC_IF(ch));
regmap_update_bits(priv->regmap, cc->ccmr_reg, cc->ccmr_mask,
cc->ccmr_bits);
regmap_set_bits(priv->regmap, TIM_CCER, cc->ccer_bits);
} else {
regmap_clear_bits(priv->regmap, TIM_CCER, cc->ccer_bits);
regmap_clear_bits(priv->regmap, cc->ccmr_reg, cc->ccmr_mask);
}
regmap_read(priv->regmap, cc->ccmr_reg, &ccmr);
regmap_read(priv->regmap, TIM_CCER, &ccer);
dev_dbg(counter->parent, "%s(%s) ch%d 0x%08x 0x%08x\n", __func__, enable ? "ena" : "dis",
ch, ccmr, ccer);
return 0;
}
static int stm32_count_events_configure(struct counter_device *counter)
{
struct stm32_timer_cnt *const priv = counter_priv(counter);
struct counter_event_node *event_node;
u32 dier = 0;
int i, ret;
list_for_each_entry(event_node, &counter->events_list, l) {
switch (event_node->event) {
case COUNTER_EVENT_OVERFLOW_UNDERFLOW:
/* first clear possibly latched UIF before enabling */
if (!regmap_test_bits(priv->regmap, TIM_DIER, TIM_DIER_UIE))
regmap_write(priv->regmap, TIM_SR, (u32)~TIM_SR_UIF);
dier |= TIM_DIER_UIE;
break;
case COUNTER_EVENT_CAPTURE:
ret = stm32_count_capture_configure(counter, event_node->channel, true);
if (ret)
return ret;
dier |= TIM_DIER_CC_IE(event_node->channel);
break;
default:
/* should never reach this path */
return -EINVAL;
}
}
/* Enable / disable all events at once, from events_list, so write all DIER bits */
regmap_write(priv->regmap, TIM_DIER, dier);
/* check for disabled capture events */
for (i = 0 ; i < priv->nchannels; i++) {
if (!(dier & TIM_DIER_CC_IE(i))) {
ret = stm32_count_capture_configure(counter, i, false);
if (ret)
return ret;
}
}
return 0;
}
static int stm32_count_watch_validate(struct counter_device *counter,
const struct counter_watch *watch)
{
struct stm32_timer_cnt *const priv = counter_priv(counter);
/* Interrupts are optional */
if (!priv->nr_irqs)
return -EOPNOTSUPP;
switch (watch->event) {
case COUNTER_EVENT_CAPTURE:
if (watch->channel >= priv->nchannels) {
dev_err(counter->parent, "Invalid channel %d\n", watch->channel);
return -EINVAL;
}
return 0;
case COUNTER_EVENT_OVERFLOW_UNDERFLOW:
return 0;
default:
return -EINVAL;
}
}
static const struct counter_ops stm32_timer_cnt_ops = {
.count_read = stm32_count_read,
.count_write = stm32_count_write,
.function_read = stm32_count_function_read,
.function_write = stm32_count_function_write,
.action_read = stm32_action_read,
.events_configure = stm32_count_events_configure,
.watch_validate = stm32_count_watch_validate,
};
static int stm32_count_clk_get_freq(struct counter_device *counter,
struct counter_signal *signal, u64 *freq)
{
struct stm32_timer_cnt *const priv = counter_priv(counter);
*freq = clk_get_rate(priv->clk);
return 0;
}
static struct counter_comp stm32_count_clock_ext[] = {
COUNTER_COMP_FREQUENCY(stm32_count_clk_get_freq),
};
static struct counter_signal stm32_signals[] = {
/*
* Need to declare all the signals as a static array, and keep the signals order here,
* even if they're unused or unexisting on some timer instances. It's an abstraction,
* e.g. high level view of the counter features.
*
* Userspace programs may rely on signal0 to be "Channel 1", signal1 to be "Channel 2",
* and so on. When a signal is unexisting, the COUNTER_SYNAPSE_ACTION_NONE can be used,
* to indicate that a signal doesn't affect the counter.
*/
{
.id = STM32_CH1_SIG,
.name = "Channel 1"
},
{
.id = STM32_CH2_SIG,
.name = "Channel 2"
},
{
.id = STM32_CLOCK_SIG,
.name = "Clock",
.ext = stm32_count_clock_ext,
.num_ext = ARRAY_SIZE(stm32_count_clock_ext),
},
{
.id = STM32_CH3_SIG,
.name = "Channel 3"
},
{
.id = STM32_CH4_SIG,
.name = "Channel 4"
},
};
static struct counter_synapse stm32_count_synapses[] = {
{
.actions_list = stm32_synapse_actions,
.num_actions = ARRAY_SIZE(stm32_synapse_actions),
.signal = &stm32_signals[STM32_CH1_SIG]
},
{
.actions_list = stm32_synapse_actions,
.num_actions = ARRAY_SIZE(stm32_synapse_actions),
.signal = &stm32_signals[STM32_CH2_SIG]
},
{
.actions_list = stm32_clock_synapse_actions,
.num_actions = ARRAY_SIZE(stm32_clock_synapse_actions),
.signal = &stm32_signals[STM32_CLOCK_SIG]
},
{
.actions_list = stm32_synapse_actions,
.num_actions = ARRAY_SIZE(stm32_synapse_actions),
.signal = &stm32_signals[STM32_CH3_SIG]
},
{
.actions_list = stm32_synapse_actions,
.num_actions = ARRAY_SIZE(stm32_synapse_actions),
.signal = &stm32_signals[STM32_CH4_SIG]
},
};
static struct counter_count stm32_counts = {
.id = 0,
.name = "STM32 Timer Counter",
.functions_list = stm32_count_functions,
.num_functions = ARRAY_SIZE(stm32_count_functions),
.synapses = stm32_count_synapses,
.num_synapses = ARRAY_SIZE(stm32_count_synapses),
.ext = stm32_count_ext,
.num_ext = ARRAY_SIZE(stm32_count_ext)
};
static irqreturn_t stm32_timer_cnt_isr(int irq, void *ptr)
{
struct counter_device *counter = ptr;
struct stm32_timer_cnt *const priv = counter_priv(counter);
u32 clr = GENMASK(31, 0); /* SR flags can be cleared by writing 0 (wr 1 has no effect) */
u32 sr, dier;
int i;
regmap_read(priv->regmap, TIM_SR, &sr);
regmap_read(priv->regmap, TIM_DIER, &dier);
/*
* Some status bits in SR don't match with the enable bits in DIER. Only take care of
* the possibly enabled bits in DIER (that matches in between SR and DIER).
*/
dier &= (TIM_DIER_UIE | TIM_DIER_CC1IE | TIM_DIER_CC2IE | TIM_DIER_CC3IE | TIM_DIER_CC4IE);
sr &= dier;
if (sr & TIM_SR_UIF) {
spin_lock(&priv->lock);
priv->nb_ovf++;
spin_unlock(&priv->lock);
counter_push_event(counter, COUNTER_EVENT_OVERFLOW_UNDERFLOW, 0);
dev_dbg(counter->parent, "COUNTER_EVENT_OVERFLOW_UNDERFLOW\n");
/* SR flags can be cleared by writing 0, only clear relevant flag */
clr &= ~TIM_SR_UIF;
}
/* Check capture events */
for (i = 0 ; i < priv->nchannels; i++) {
if (sr & TIM_SR_CC_IF(i)) {
counter_push_event(counter, COUNTER_EVENT_CAPTURE, i);
clr &= ~TIM_SR_CC_IF(i);
dev_dbg(counter->parent, "COUNTER_EVENT_CAPTURE, %d\n", i);
}
}
regmap_write(priv->regmap, TIM_SR, clr);
return IRQ_HANDLED;
};
static void stm32_timer_cnt_detect_channels(struct device *dev,
struct stm32_timer_cnt *priv)
{
u32 ccer, ccer_backup;
regmap_read(priv->regmap, TIM_CCER, &ccer_backup);
regmap_set_bits(priv->regmap, TIM_CCER, TIM_CCER_CCXE);
regmap_read(priv->regmap, TIM_CCER, &ccer);
regmap_write(priv->regmap, TIM_CCER, ccer_backup);
priv->nchannels = hweight32(ccer & TIM_CCER_CCXE);
dev_dbg(dev, "has %d cc channels\n", priv->nchannels);
}
/* encoder supported on TIM1 TIM2 TIM3 TIM4 TIM5 TIM8 */
#define STM32_TIM_ENCODER_SUPPORTED (BIT(0) | BIT(1) | BIT(2) | BIT(3) | BIT(4) | BIT(7))
static const char * const stm32_timer_trigger_compat[] = {
"st,stm32-timer-trigger",
"st,stm32h7-timer-trigger",
};
static int stm32_timer_cnt_probe_encoder(struct device *dev,
struct stm32_timer_cnt *priv)
{
struct device *parent = dev->parent;
struct device_node *tnode = NULL, *pnode = parent->of_node;
int i, ret;
u32 idx;
/*
* Need to retrieve the trigger node index from DT, to be able
* to determine if the counter supports encoder mode. It also
* enforce backward compatibility, and allow to support other
* counter modes in this driver (when the timer doesn't support
* encoder).
*/
for (i = 0; i < ARRAY_SIZE(stm32_timer_trigger_compat) && !tnode; i++)
tnode = of_get_compatible_child(pnode, stm32_timer_trigger_compat[i]);
if (!tnode) {
dev_err(dev, "Can't find trigger node\n");
return -ENODATA;
}
ret = of_property_read_u32(tnode, "reg", &idx);
if (ret) {
dev_err(dev, "Can't get index (%d)\n", ret);
return ret;
}
priv->has_encoder = !!(STM32_TIM_ENCODER_SUPPORTED & BIT(idx));
dev_dbg(dev, "encoder support: %s\n", priv->has_encoder ? "yes" : "no");
return 0;
}
static int stm32_timer_cnt_probe(struct platform_device *pdev)
{
struct stm32_timers *ddata = dev_get_drvdata(pdev->dev.parent);
struct device *dev = &pdev->dev;
struct stm32_timer_cnt *priv;
struct counter_device *counter;
int i, ret;
if (IS_ERR_OR_NULL(ddata))
return -EINVAL;
counter = devm_counter_alloc(dev, sizeof(*priv));
if (!counter)
return -ENOMEM;
priv = counter_priv(counter);
priv->regmap = ddata->regmap;
priv->clk = ddata->clk;
priv->max_arr = ddata->max_arr;
priv->nr_irqs = ddata->nr_irqs;
ret = stm32_timer_cnt_probe_encoder(dev, priv);
if (ret)
return ret;
stm32_timer_cnt_detect_channels(dev, priv);
counter->name = dev_name(dev);
counter->parent = dev;
counter->ops = &stm32_timer_cnt_ops;
counter->counts = &stm32_counts;
counter->num_counts = 1;
counter->signals = stm32_signals;
counter->num_signals = ARRAY_SIZE(stm32_signals);
spin_lock_init(&priv->lock);
platform_set_drvdata(pdev, priv);
/* STM32 Timers can have either 1 global, or 4 dedicated interrupts (optional) */
if (priv->nr_irqs == 1) {
/* All events reported through the global interrupt */
ret = devm_request_irq(&pdev->dev, ddata->irq[0], stm32_timer_cnt_isr,
0, dev_name(dev), counter);
if (ret) {
dev_err(dev, "Failed to request irq %d (err %d)\n",
ddata->irq[0], ret);
return ret;
}
} else {
for (i = 0; i < priv->nr_irqs; i++) {
/*
* Only take care of update IRQ for overflow events, and cc for
* capture events.
*/
if (i != STM32_TIMERS_IRQ_UP && i != STM32_TIMERS_IRQ_CC)
continue;
ret = devm_request_irq(&pdev->dev, ddata->irq[i], stm32_timer_cnt_isr,
0, dev_name(dev), counter);
if (ret) {
dev_err(dev, "Failed to request irq %d (err %d)\n",
ddata->irq[i], ret);
return ret;
}
}
}
/* Reset input selector to its default input */
regmap_write(priv->regmap, TIM_TISEL, 0x0);
/* Register Counter device */
ret = devm_counter_add(dev, counter);
if (ret < 0)
dev_err_probe(dev, ret, "Failed to add counter\n");
return ret;
}
static int __maybe_unused stm32_timer_cnt_suspend(struct device *dev)
{
struct stm32_timer_cnt *priv = dev_get_drvdata(dev);
/* Only take care of enabled counter: don't disturb other MFD child */
if (priv->enabled) {
/* Backup registers that may get lost in low power mode */
regmap_read(priv->regmap, TIM_SMCR, &priv->bak.smcr);
regmap_read(priv->regmap, TIM_ARR, &priv->bak.arr);
regmap_read(priv->regmap, TIM_CNT, &priv->bak.cnt);
regmap_read(priv->regmap, TIM_CR1, &priv->bak.cr1);
/* Disable the counter */
regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN, 0);
clk_disable(priv->clk);
}
return pinctrl_pm_select_sleep_state(dev);
}
static int __maybe_unused stm32_timer_cnt_resume(struct device *dev)
{
struct stm32_timer_cnt *priv = dev_get_drvdata(dev);
int ret;
ret = pinctrl_pm_select_default_state(dev);
if (ret)
return ret;
if (priv->enabled) {
clk_enable(priv->clk);
/* Restore registers that may have been lost */
regmap_write(priv->regmap, TIM_SMCR, priv->bak.smcr);
regmap_write(priv->regmap, TIM_ARR, priv->bak.arr);
regmap_write(priv->regmap, TIM_CNT, priv->bak.cnt);
/* Also re-enables the counter */
regmap_write(priv->regmap, TIM_CR1, priv->bak.cr1);
}
return 0;
}
static SIMPLE_DEV_PM_OPS(stm32_timer_cnt_pm_ops, stm32_timer_cnt_suspend,
stm32_timer_cnt_resume);
static const struct of_device_id stm32_timer_cnt_of_match[] = {
{ .compatible = "st,stm32-timer-counter", },
{},
};
MODULE_DEVICE_TABLE(of, stm32_timer_cnt_of_match);
static struct platform_driver stm32_timer_cnt_driver = {
.probe = stm32_timer_cnt_probe,
.driver = {
.name = "stm32-timer-counter",
.of_match_table = stm32_timer_cnt_of_match,
.pm = &stm32_timer_cnt_pm_ops,
},
};
module_platform_driver(stm32_timer_cnt_driver);
MODULE_AUTHOR("Benjamin Gaignard <benjamin.gaignard@st.com>");
MODULE_ALIAS("platform:stm32-timer-counter");
MODULE_DESCRIPTION("STMicroelectronics STM32 TIMER counter driver");
MODULE_LICENSE("GPL v2");
MODULE_IMPORT_NS(COUNTER);