Preston_PLB/kernel-aes67
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gpio: sim: don't fiddle with GPIOLIB private members

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We access internals of struct gpio_device and struct gpio_desc because
it's easier but it can actually be avoided and we're working towards a
better encapsulation of GPIO data structures across the kernel so let's
start at home.

Instead of checking gpio_desc flags, let's just track the requests of
GPIOs in the driver. We also already store the information about
direction of simulated lines.

For kobjects needed by sysfs callbacks: we can iterate over the children
devices of the top-level platform device and compare their fwnodes
against the one passed to the init function from probe.

While at it: fix one line break and remove the untrue part about
configfs callbacks using dev_get_drvdata() from a comment.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
This commit is contained in:
Bartosz Golaszewski 2023-09-11 13:07:40 +02:00
parent 9a249ec89a
commit 88d31f836b
1 changed files with 51 additions and 19 deletions
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70
drivers/gpio/gpio-sim.c
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@ -12,6 +12,7 @@
#include <linux/completion.h>
#include <linux/configfs.h>
#include <linux/device.h>
#include <linux/gpio/consumer.h>
#include <linux/gpio/driver.h>
#include <linux/gpio/machine.h>
#include <linux/idr.h>
@ -30,8 +31,6 @@
#include <linux/string_helpers.h>
#include <linux/sysfs.h>
#include "gpiolib.h"
#define GPIO_SIM_NGPIO_MAX 1024
#define GPIO_SIM_PROP_MAX 4 /* Max 3 properties + sentinel. */
#define GPIO_SIM_NUM_ATTRS 3 /* value, pull and sentinel */
@ -40,6 +39,8 @@ static DEFINE_IDA(gpio_sim_ida);
struct gpio_sim_chip {
struct gpio_chip gc;
struct device *dev;
unsigned long *request_map;
unsigned long *direction_map;
unsigned long *value_map;
unsigned long *pull_map;
@ -63,16 +64,11 @@ static int gpio_sim_apply_pull(struct gpio_sim_chip *chip,
unsigned int offset, int value)
{
int irq, irq_type, ret;
struct gpio_desc *desc;
struct gpio_chip *gc;
gc = &chip->gc;
desc = &gc->gpiodev->descs[offset];
guard(mutex)(&chip->lock);
if (test_bit(FLAG_REQUESTED, &desc->flags) &&
!test_bit(FLAG_IS_OUT, &desc->flags)) {
if (test_bit(offset, chip->request_map) &&
test_bit(offset, chip->direction_map)) {
if (value == !!test_bit(offset, chip->value_map))
goto set_pull;
@ -99,8 +95,8 @@ static int gpio_sim_apply_pull(struct gpio_sim_chip *chip,
set_value:
/* Change the value unless we're actively driving the line. */
if (!test_bit(FLAG_REQUESTED, &desc->flags) ||
!test_bit(FLAG_IS_OUT, &desc->flags))
if (!test_bit(offset, chip->request_map) ||
test_bit(offset, chip->direction_map))
__assign_bit(offset, chip->value_map, value);
set_pull:
@ -180,8 +176,8 @@ static int gpio_sim_get_direction(struct gpio_chip *gc, unsigned int offset)
return direction ? GPIO_LINE_DIRECTION_IN : GPIO_LINE_DIRECTION_OUT;
}
static int gpio_sim_set_config(struct gpio_chip *gc,
unsigned int offset, unsigned long config)
static int gpio_sim_set_config(struct gpio_chip *gc, unsigned int offset,
unsigned long config)
{
struct gpio_sim_chip *chip = gpiochip_get_data(gc);
@ -204,13 +200,25 @@ static int gpio_sim_to_irq(struct gpio_chip *gc, unsigned int offset)
return irq_create_mapping(chip->irq_sim, offset);
}
static void gpio_sim_free(struct gpio_chip *gc, unsigned int offset)
static int gpio_sim_request(struct gpio_chip *gc, unsigned int offset)
{
struct gpio_sim_chip *chip = gpiochip_get_data(gc);
scoped_guard(mutex, &chip->lock)
__set_bit(offset, chip->request_map);
return 0;
}
static void gpio_sim_free(struct gpio_chip *gc, unsigned int offset)
{
struct gpio_sim_chip *chip = gpiochip_get_data(gc);
scoped_guard(mutex, &chip->lock) {
__assign_bit(offset, chip->value_map,
!!test_bit(offset, chip->pull_map));
__clear_bit(offset, chip->request_map);
}
}
static ssize_t gpio_sim_sysfs_val_show(struct device *dev,
@ -282,6 +290,13 @@ static void gpio_sim_mutex_destroy(void *data)
mutex_destroy(lock);
}
static void gpio_sim_put_device(void *data)
{
struct device *dev = data;
put_device(dev);
}
static void gpio_sim_dispose_mappings(void *data)
{
struct gpio_sim_chip *chip = data;
@ -295,7 +310,7 @@ static void gpio_sim_sysfs_remove(void *data)
{
struct gpio_sim_chip *chip = data;
sysfs_remove_groups(&chip->gc.gpiodev->dev.kobj, chip->attr_groups);
sysfs_remove_groups(&chip->dev->kobj, chip->attr_groups);
}
static int gpio_sim_setup_sysfs(struct gpio_sim_chip *chip)
@ -352,14 +367,18 @@ static int gpio_sim_setup_sysfs(struct gpio_sim_chip *chip)
chip->attr_groups[i] = attr_group;
}
ret = sysfs_create_groups(&chip->gc.gpiodev->dev.kobj,
chip->attr_groups);
ret = sysfs_create_groups(&chip->dev->kobj, chip->attr_groups);
if (ret)
return ret;
return devm_add_action_or_reset(dev, gpio_sim_sysfs_remove, chip);
}
static int gpio_sim_dev_match_fwnode(struct device *dev, void *data)
{
return device_match_fwnode(dev, data);
}
static int gpio_sim_add_bank(struct fwnode_handle *swnode, struct device *dev)
{
struct gpio_sim_chip *chip;
@ -387,6 +406,10 @@ static int gpio_sim_add_bank(struct fwnode_handle *swnode, struct device *dev)
if (!chip)
return -ENOMEM;
chip->request_map = devm_bitmap_zalloc(dev, num_lines, GFP_KERNEL);
if (!chip->request_map)
return -ENOMEM;
chip->direction_map = devm_bitmap_alloc(dev, num_lines, GFP_KERNEL);
if (!chip->direction_map)
return -ENOMEM;
@ -432,6 +455,7 @@ static int gpio_sim_add_bank(struct fwnode_handle *swnode, struct device *dev)
gc->get_direction = gpio_sim_get_direction;
gc->set_config = gpio_sim_set_config;
gc->to_irq = gpio_sim_to_irq;
gc->request = gpio_sim_request;
gc->free = gpio_sim_free;
gc->can_sleep = true;
@ -439,8 +463,16 @@ static int gpio_sim_add_bank(struct fwnode_handle *swnode, struct device *dev)
if (ret)
return ret;
/* Used by sysfs and configfs callbacks. */
dev_set_drvdata(&gc->gpiodev->dev, chip);
chip->dev = device_find_child(dev, swnode, gpio_sim_dev_match_fwnode);
if (!chip->dev)
return -ENODEV;
ret = devm_add_action_or_reset(dev, gpio_sim_put_device, chip->dev);
if (ret)
return ret;
/* Used by sysfs callbacks. */
dev_set_drvdata(chip->dev, chip);
return gpio_sim_setup_sysfs(chip);
}