ubuntu-linux-kernel/drivers/pinctrl/meson/pinctrl-meson8-pmx.c

109 lines
3.2 KiB
C

/*
* First generation of pinmux driver for Amlogic Meson SoCs
*
* Copyright (C) 2014 Beniamino Galvani <b.galvani@gmail.com>
* Copyright (C) 2017 Jerome Brunet <jbrunet@baylibre.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* version 2 as published by the Free Software Foundation.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/* For this first generation of pinctrl driver every pinmux group can be
* enabled by a specific bit in the first register range. When all groups for
* a given pin are disabled the pin acts as a GPIO.
*/
#include <linux/device.h>
#include <linux/regmap.h>
#include <linux/pinctrl/pinctrl.h>
#include <linux/pinctrl/pinmux.h>
#include "pinctrl-meson.h"
#include "pinctrl-meson8-pmx.h"
/**
* meson8_pmx_disable_other_groups() - disable other groups using a given pin
*
* @pc: meson pin controller device
* @pin: number of the pin
* @sel_group: index of the selected group, or -1 if none
*
* The function disables all pinmux groups using a pin except the
* selected one. If @sel_group is -1 all groups are disabled, leaving
* the pin in GPIO mode.
*/
static void meson8_pmx_disable_other_groups(struct meson_pinctrl *pc,
unsigned int pin, int sel_group)
{
struct meson_pmx_group *group;
struct meson8_pmx_data *pmx_data;
int i, j;
for (i = 0; i < pc->data->num_groups; i++) {
group = &pc->data->groups[i];
pmx_data = (struct meson8_pmx_data *)group->data;
if (pmx_data->is_gpio || i == sel_group)
continue;
for (j = 0; j < group->num_pins; j++) {
if (group->pins[j] == pin) {
/* We have found a group using the pin */
regmap_update_bits(pc->reg_mux,
pmx_data->reg * 4,
BIT(pmx_data->bit), 0);
}
}
}
}
static int meson8_pmx_set_mux(struct pinctrl_dev *pcdev, unsigned func_num,
unsigned group_num)
{
struct meson_pinctrl *pc = pinctrl_dev_get_drvdata(pcdev);
struct meson_pmx_func *func = &pc->data->funcs[func_num];
struct meson_pmx_group *group = &pc->data->groups[group_num];
struct meson8_pmx_data *pmx_data =
(struct meson8_pmx_data *)group->data;
int i, ret = 0;
dev_dbg(pc->dev, "enable function %s, group %s\n", func->name,
group->name);
/*
* Disable groups using the same pin.
* The selected group is not disabled to avoid glitches.
*/
for (i = 0; i < group->num_pins; i++)
meson8_pmx_disable_other_groups(pc, group->pins[i], group_num);
/* Function 0 (GPIO) doesn't need any additional setting */
if (func_num)
ret = regmap_update_bits(pc->reg_mux, pmx_data->reg * 4,
BIT(pmx_data->bit),
BIT(pmx_data->bit));
return ret;
}
static int meson8_pmx_request_gpio(struct pinctrl_dev *pcdev,
struct pinctrl_gpio_range *range,
unsigned offset)
{
struct meson_pinctrl *pc = pinctrl_dev_get_drvdata(pcdev);
meson8_pmx_disable_other_groups(pc, offset, -1);
return 0;
}
const struct pinmux_ops meson8_pmx_ops = {
.set_mux = meson8_pmx_set_mux,
.get_functions_count = meson_pmx_get_funcs_count,
.get_function_name = meson_pmx_get_func_name,
.get_function_groups = meson_pmx_get_groups,
.gpio_request_enable = meson8_pmx_request_gpio,
};