linux/drivers/counter/microchip-tcb-capture.c
William Breathitt Gray d917a62af8 counter: microchip-tcb-capture: Handle Signal1 read and Synapse
The signal_read(), action_read(), and action_write() callbacks have been
assuming Signal0 is requested without checking. This results in requests
for Signal1 returning data for Signal0. This patch fixes these
oversights by properly checking for the Signal's id in the respective
callbacks and handling accordingly based on the particular Signal
requested. The trig_inverted member of the mchp_tc_data is removed as
superfluous.

Fixes: 106b104137 ("counter: Add microchip TCB capture counter")
Cc: stable@vger.kernel.org
Reviewed-by: Kamel Bouhara <kamel.bouhara@bootlin.com>
Link: https://lore.kernel.org/r/20221018121014.7368-1-william.gray@linaro.org/
Signed-off-by: William Breathitt Gray <william.gray@linaro.org>
2022-10-23 20:38:49 -04:00

408 lines
10 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2020 Microchip
*
* Author: Kamel Bouhara <kamel.bouhara@bootlin.com>
*/
#include <linux/clk.h>
#include <linux/counter.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <soc/at91/atmel_tcb.h>
#define ATMEL_TC_CMR_MASK (ATMEL_TC_LDRA_RISING | ATMEL_TC_LDRB_FALLING | \
ATMEL_TC_ETRGEDG_RISING | ATMEL_TC_LDBDIS | \
ATMEL_TC_LDBSTOP)
#define ATMEL_TC_QDEN BIT(8)
#define ATMEL_TC_POSEN BIT(9)
struct mchp_tc_data {
const struct atmel_tcb_config *tc_cfg;
struct regmap *regmap;
int qdec_mode;
int num_channels;
int channel[2];
};
static const enum counter_function mchp_tc_count_functions[] = {
COUNTER_FUNCTION_INCREASE,
COUNTER_FUNCTION_QUADRATURE_X4,
};
static const enum counter_synapse_action mchp_tc_synapse_actions[] = {
COUNTER_SYNAPSE_ACTION_NONE,
COUNTER_SYNAPSE_ACTION_RISING_EDGE,
COUNTER_SYNAPSE_ACTION_FALLING_EDGE,
COUNTER_SYNAPSE_ACTION_BOTH_EDGES,
};
static struct counter_signal mchp_tc_count_signals[] = {
{
.id = 0,
.name = "Channel A",
},
{
.id = 1,
.name = "Channel B",
}
};
static struct counter_synapse mchp_tc_count_synapses[] = {
{
.actions_list = mchp_tc_synapse_actions,
.num_actions = ARRAY_SIZE(mchp_tc_synapse_actions),
.signal = &mchp_tc_count_signals[0]
},
{
.actions_list = mchp_tc_synapse_actions,
.num_actions = ARRAY_SIZE(mchp_tc_synapse_actions),
.signal = &mchp_tc_count_signals[1]
}
};
static int mchp_tc_count_function_read(struct counter_device *counter,
struct counter_count *count,
enum counter_function *function)
{
struct mchp_tc_data *const priv = counter_priv(counter);
if (priv->qdec_mode)
*function = COUNTER_FUNCTION_QUADRATURE_X4;
else
*function = COUNTER_FUNCTION_INCREASE;
return 0;
}
static int mchp_tc_count_function_write(struct counter_device *counter,
struct counter_count *count,
enum counter_function function)
{
struct mchp_tc_data *const priv = counter_priv(counter);
u32 bmr, cmr;
regmap_read(priv->regmap, ATMEL_TC_BMR, &bmr);
regmap_read(priv->regmap, ATMEL_TC_REG(priv->channel[0], CMR), &cmr);
/* Set capture mode */
cmr &= ~ATMEL_TC_WAVE;
switch (function) {
case COUNTER_FUNCTION_INCREASE:
priv->qdec_mode = 0;
/* Set highest rate based on whether soc has gclk or not */
bmr &= ~(ATMEL_TC_QDEN | ATMEL_TC_POSEN);
if (priv->tc_cfg->has_gclk)
cmr |= ATMEL_TC_TIMER_CLOCK2;
else
cmr |= ATMEL_TC_TIMER_CLOCK1;
/* Setup the period capture mode */
cmr |= ATMEL_TC_CMR_MASK;
cmr &= ~(ATMEL_TC_ABETRG | ATMEL_TC_XC0);
break;
case COUNTER_FUNCTION_QUADRATURE_X4:
if (!priv->tc_cfg->has_qdec)
return -EINVAL;
/* In QDEC mode settings both channels 0 and 1 are required */
if (priv->num_channels < 2 || priv->channel[0] != 0 ||
priv->channel[1] != 1) {
pr_err("Invalid channels number or id for quadrature mode\n");
return -EINVAL;
}
priv->qdec_mode = 1;
bmr |= ATMEL_TC_QDEN | ATMEL_TC_POSEN;
cmr |= ATMEL_TC_ETRGEDG_RISING | ATMEL_TC_ABETRG | ATMEL_TC_XC0;
break;
default:
/* should never reach this path */
return -EINVAL;
}
regmap_write(priv->regmap, ATMEL_TC_BMR, bmr);
regmap_write(priv->regmap, ATMEL_TC_REG(priv->channel[0], CMR), cmr);
/* Enable clock and trigger counter */
regmap_write(priv->regmap, ATMEL_TC_REG(priv->channel[0], CCR),
ATMEL_TC_CLKEN | ATMEL_TC_SWTRG);
if (priv->qdec_mode) {
regmap_write(priv->regmap,
ATMEL_TC_REG(priv->channel[1], CMR), cmr);
regmap_write(priv->regmap,
ATMEL_TC_REG(priv->channel[1], CCR),
ATMEL_TC_CLKEN | ATMEL_TC_SWTRG);
}
return 0;
}
static int mchp_tc_count_signal_read(struct counter_device *counter,
struct counter_signal *signal,
enum counter_signal_level *lvl)
{
struct mchp_tc_data *const priv = counter_priv(counter);
bool sigstatus;
u32 sr;
regmap_read(priv->regmap, ATMEL_TC_REG(priv->channel[0], SR), &sr);
if (signal->id == 1)
sigstatus = (sr & ATMEL_TC_MTIOB);
else
sigstatus = (sr & ATMEL_TC_MTIOA);
*lvl = sigstatus ? COUNTER_SIGNAL_LEVEL_HIGH : COUNTER_SIGNAL_LEVEL_LOW;
return 0;
}
static int mchp_tc_count_action_read(struct counter_device *counter,
struct counter_count *count,
struct counter_synapse *synapse,
enum counter_synapse_action *action)
{
struct mchp_tc_data *const priv = counter_priv(counter);
u32 cmr;
if (priv->qdec_mode) {
*action = COUNTER_SYNAPSE_ACTION_BOTH_EDGES;
return 0;
}
/* Only TIOA signal is evaluated in non-QDEC mode */
if (synapse->signal->id != 0) {
*action = COUNTER_SYNAPSE_ACTION_NONE;
return 0;
}
regmap_read(priv->regmap, ATMEL_TC_REG(priv->channel[0], CMR), &cmr);
switch (cmr & ATMEL_TC_ETRGEDG) {
default:
*action = COUNTER_SYNAPSE_ACTION_NONE;
break;
case ATMEL_TC_ETRGEDG_RISING:
*action = COUNTER_SYNAPSE_ACTION_RISING_EDGE;
break;
case ATMEL_TC_ETRGEDG_FALLING:
*action = COUNTER_SYNAPSE_ACTION_FALLING_EDGE;
break;
case ATMEL_TC_ETRGEDG_BOTH:
*action = COUNTER_SYNAPSE_ACTION_BOTH_EDGES;
break;
}
return 0;
}
static int mchp_tc_count_action_write(struct counter_device *counter,
struct counter_count *count,
struct counter_synapse *synapse,
enum counter_synapse_action action)
{
struct mchp_tc_data *const priv = counter_priv(counter);
u32 edge = ATMEL_TC_ETRGEDG_NONE;
/* QDEC mode is rising edge only; only TIOA handled in non-QDEC mode */
if (priv->qdec_mode || synapse->signal->id != 0)
return -EINVAL;
switch (action) {
case COUNTER_SYNAPSE_ACTION_NONE:
edge = ATMEL_TC_ETRGEDG_NONE;
break;
case COUNTER_SYNAPSE_ACTION_RISING_EDGE:
edge = ATMEL_TC_ETRGEDG_RISING;
break;
case COUNTER_SYNAPSE_ACTION_FALLING_EDGE:
edge = ATMEL_TC_ETRGEDG_FALLING;
break;
case COUNTER_SYNAPSE_ACTION_BOTH_EDGES:
edge = ATMEL_TC_ETRGEDG_BOTH;
break;
default:
/* should never reach this path */
return -EINVAL;
}
return regmap_write_bits(priv->regmap,
ATMEL_TC_REG(priv->channel[0], CMR),
ATMEL_TC_ETRGEDG, edge);
}
static int mchp_tc_count_read(struct counter_device *counter,
struct counter_count *count, u64 *val)
{
struct mchp_tc_data *const priv = counter_priv(counter);
u32 cnt;
regmap_read(priv->regmap, ATMEL_TC_REG(priv->channel[0], CV), &cnt);
*val = cnt;
return 0;
}
static struct counter_count mchp_tc_counts[] = {
{
.id = 0,
.name = "Timer Counter",
.functions_list = mchp_tc_count_functions,
.num_functions = ARRAY_SIZE(mchp_tc_count_functions),
.synapses = mchp_tc_count_synapses,
.num_synapses = ARRAY_SIZE(mchp_tc_count_synapses),
},
};
static const struct counter_ops mchp_tc_ops = {
.signal_read = mchp_tc_count_signal_read,
.count_read = mchp_tc_count_read,
.function_read = mchp_tc_count_function_read,
.function_write = mchp_tc_count_function_write,
.action_read = mchp_tc_count_action_read,
.action_write = mchp_tc_count_action_write
};
static const struct atmel_tcb_config tcb_rm9200_config = {
.counter_width = 16,
};
static const struct atmel_tcb_config tcb_sam9x5_config = {
.counter_width = 32,
};
static const struct atmel_tcb_config tcb_sama5d2_config = {
.counter_width = 32,
.has_gclk = true,
.has_qdec = true,
};
static const struct atmel_tcb_config tcb_sama5d3_config = {
.counter_width = 32,
.has_qdec = true,
};
static const struct of_device_id atmel_tc_of_match[] = {
{ .compatible = "atmel,at91rm9200-tcb", .data = &tcb_rm9200_config, },
{ .compatible = "atmel,at91sam9x5-tcb", .data = &tcb_sam9x5_config, },
{ .compatible = "atmel,sama5d2-tcb", .data = &tcb_sama5d2_config, },
{ .compatible = "atmel,sama5d3-tcb", .data = &tcb_sama5d3_config, },
{ /* sentinel */ }
};
static void mchp_tc_clk_remove(void *ptr)
{
clk_disable_unprepare((struct clk *)ptr);
}
static int mchp_tc_probe(struct platform_device *pdev)
{
struct device_node *np = pdev->dev.of_node;
const struct atmel_tcb_config *tcb_config;
const struct of_device_id *match;
struct counter_device *counter;
struct mchp_tc_data *priv;
char clk_name[7];
struct regmap *regmap;
struct clk *clk[3];
int channel;
int ret, i;
counter = devm_counter_alloc(&pdev->dev, sizeof(*priv));
if (!counter)
return -ENOMEM;
priv = counter_priv(counter);
match = of_match_node(atmel_tc_of_match, np->parent);
tcb_config = match->data;
if (!tcb_config) {
dev_err(&pdev->dev, "No matching parent node found\n");
return -ENODEV;
}
regmap = syscon_node_to_regmap(np->parent);
if (IS_ERR(regmap))
return PTR_ERR(regmap);
/* max. channels number is 2 when in QDEC mode */
priv->num_channels = of_property_count_u32_elems(np, "reg");
if (priv->num_channels < 0) {
dev_err(&pdev->dev, "Invalid or missing channel\n");
return -EINVAL;
}
/* Register channels and initialize clocks */
for (i = 0; i < priv->num_channels; i++) {
ret = of_property_read_u32_index(np, "reg", i, &channel);
if (ret < 0 || channel > 2)
return -ENODEV;
priv->channel[i] = channel;
snprintf(clk_name, sizeof(clk_name), "t%d_clk", channel);
clk[i] = of_clk_get_by_name(np->parent, clk_name);
if (IS_ERR(clk[i])) {
/* Fallback to t0_clk */
clk[i] = of_clk_get_by_name(np->parent, "t0_clk");
if (IS_ERR(clk[i]))
return PTR_ERR(clk[i]);
}
ret = clk_prepare_enable(clk[i]);
if (ret)
return ret;
ret = devm_add_action_or_reset(&pdev->dev,
mchp_tc_clk_remove,
clk[i]);
if (ret)
return ret;
dev_dbg(&pdev->dev,
"Initialized capture mode on channel %d\n",
channel);
}
priv->tc_cfg = tcb_config;
priv->regmap = regmap;
counter->name = dev_name(&pdev->dev);
counter->parent = &pdev->dev;
counter->ops = &mchp_tc_ops;
counter->num_counts = ARRAY_SIZE(mchp_tc_counts);
counter->counts = mchp_tc_counts;
counter->num_signals = ARRAY_SIZE(mchp_tc_count_signals);
counter->signals = mchp_tc_count_signals;
ret = devm_counter_add(&pdev->dev, counter);
if (ret < 0)
return dev_err_probe(&pdev->dev, ret, "Failed to add counter\n");
return 0;
}
static const struct of_device_id mchp_tc_dt_ids[] = {
{ .compatible = "microchip,tcb-capture", },
{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, mchp_tc_dt_ids);
static struct platform_driver mchp_tc_driver = {
.probe = mchp_tc_probe,
.driver = {
.name = "microchip-tcb-capture",
.of_match_table = mchp_tc_dt_ids,
},
};
module_platform_driver(mchp_tc_driver);
MODULE_AUTHOR("Kamel Bouhara <kamel.bouhara@bootlin.com>");
MODULE_DESCRIPTION("Microchip TCB Capture driver");
MODULE_LICENSE("GPL v2");
MODULE_IMPORT_NS(COUNTER);