path: root/drivers/mfd/stmpe.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * ST Microelectronics MFD: stmpe's driver
 *
 * Copyright (C) ST-Ericsson SA 2010
 *
 * Author: Rabin Vincent <rabin.vincent@stericsson.com> for ST-Ericsson
 */

#include <linux/err.h>
#include <linux/gpio/consumer.h>
#include <linux/export.h>
#include <linux/kernel.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/irqdomain.h>
#include <linux/of.h>
#include <linux/pm.h>
#include <linux/slab.h>
#include <linux/mfd/core.h>
#include <linux/delay.h>
#include <linux/regulator/consumer.h>
#include "stmpe.h"

/**
 * struct stmpe_platform_data - STMPE platform data
 * @id: device id to distinguish between multiple STMPEs on the same board
 * @blocks: bitmask of blocks to enable (use STMPE_BLOCK_*)
 * @irq_trigger: IRQ trigger to use for the interrupt to the host
 * @autosleep: bool to enable/disable stmpe autosleep
 * @autosleep_timeout: inactivity timeout in milliseconds for autosleep
 */
struct stmpe_platform_data {
	int id;
	unsigned int blocks;
	unsigned int irq_trigger;
	bool autosleep;
	int autosleep_timeout;
};

static int __stmpe_enable(struct stmpe *stmpe, unsigned int blocks)
{
	return stmpe->variant->enable(stmpe, blocks, true);
}

static int __stmpe_disable(struct stmpe *stmpe, unsigned int blocks)
{
	return stmpe->variant->enable(stmpe, blocks, false);
}

static int __stmpe_reg_read(struct stmpe *stmpe, u8 reg)
{
	int ret;

	ret = stmpe->ci->read_byte(stmpe, reg);
	if (ret < 0)
		dev_err(stmpe->dev, "failed to read reg %#x: %d\n", reg, ret);

	dev_vdbg(stmpe->dev, "rd: reg %#x => data %#x\n", reg, ret);

	return ret;
}

static int __stmpe_reg_write(struct stmpe *stmpe, u8 reg, u8 val)
{
	int ret;

	dev_vdbg(stmpe->dev, "wr: reg %#x <= %#x\n", reg, val);

	ret = stmpe->ci->write_byte(stmpe, reg, val);
	if (ret < 0)
		dev_err(stmpe->dev, "failed to write reg %#x: %d\n", reg, ret);

	return ret;
}

static int __stmpe_set_bits(struct stmpe *stmpe, u8 reg, u8 mask, u8 val)
{
	int ret;

	ret = __stmpe_reg_read(stmpe, reg);
	if (ret < 0)
		return ret;

	ret &= ~mask;
	ret |= val;

	return __stmpe_reg_write(stmpe, reg, ret);
}

static int __stmpe_block_read(struct stmpe *stmpe, u8 reg, u8 length,
			      u8 *values)
{
	int ret;

	ret = stmpe->ci->read_block(stmpe, reg, length, values);
	if (ret < 0)
		dev_err(stmpe->dev, "failed to read regs %#x: %d\n", reg, ret);

	dev_vdbg(stmpe->dev, "rd: reg %#x (%d) => ret %#x\n", reg, length, ret);
	stmpe_dump_bytes("stmpe rd: ", values, length);

	return ret;
}

static int __stmpe_block_write(struct stmpe *stmpe, u8 reg, u8 length,
			const u8 *values)
{
	int ret;

	dev_vdbg(stmpe->dev, "wr: regs %#x (%d)\n", reg, length);
	stmpe_dump_bytes("stmpe wr: ", values, length);

	ret = stmpe->ci->write_block(stmpe, reg, length, values);
	if (ret < 0)
		dev_err(stmpe->dev, "failed to write regs %#x: %d\n", reg, ret);

	return ret;
}

/**
 * stmpe_enable - enable blocks on an STMPE device
 * @stmpe:	Device to work on
 * @blocks:	Mask of blocks (enum stmpe_block values) to enable
 */
int stmpe_enable(struct stmpe *stmpe, unsigned int blocks)
{
	int ret;

	mutex_lock(&stmpe->lock);
	ret = __stmpe_enable(stmpe, blocks);
	mutex_unlock(&stmpe->lock);

	return ret;
}
EXPORT_SYMBOL_GPL(stmpe_enable);

/**
 * stmpe_disable - disable blocks on an STMPE device
 * @stmpe:	Device to work on
 * @blocks:	Mask of blocks (enum stmpe_block values) to enable
 */
int stmpe_disable(struct stmpe *stmpe, unsigned int blocks)
{
	int ret;

	mutex_lock(&stmpe->lock);
	ret = __stmpe_disable(stmpe, blocks);
	mutex_unlock(&stmpe->lock);

	return ret;
}
EXPORT_SYMBOL_GPL(stmpe_disable);

/**
 * stmpe_reg_read() - read a single STMPE register
 * @stmpe:	Device to read from
 * @reg:	Register to read
 */
int stmpe_reg_read(struct stmpe *stmpe, u8 reg)
{
	int ret;

	mutex_lock(&stmpe->lock);
	ret = __stmpe_reg_read(stmpe, reg);
	mutex_unlock(&stmpe->lock);

	return ret;
}
EXPORT_SYMBOL_GPL(stmpe_reg_read);

/**
 * stmpe_reg_write() - write a single STMPE register
 * @stmpe:	Device to write to
 * @reg:	Register to write
 * @val:	Value to write
 */
int stmpe_reg_write(struct stmpe *stmpe, u8 reg, u8 val)
{
	int ret;

	mutex_lock(&stmpe->lock);
	ret = __stmpe_reg_write(stmpe, reg, val);
	mutex_unlock(&stmpe->lock);

	return ret;
}
EXPORT_SYMBOL_GPL(stmpe_reg_write);

/**
 * stmpe_set_bits() - set the value of a bitfield in a STMPE register
 * @stmpe:	Device to write to
 * @reg:	Register to write
 * @mask:	Mask of bits to set
 * @val:	Value to set
 */
int stmpe_set_bits(struct stmpe *stmpe, u8 reg, u8 mask, u8 val)
{
	int ret;

	mutex_lock(&stmpe->lock);
	ret = __stmpe_set_bits(stmpe, reg, mask, val);
	mutex_unlock(&stmpe->lock);

	return ret;
}
EXPORT_SYMBOL_GPL(stmpe_set_bits);

/**
 * stmpe_block_read() - read multiple STMPE registers
 * @stmpe:	Device to read from
 * @reg:	First register
 * @length:	Number of registers
 * @values:	Buffer to write to
 */
int stmpe_block_read(struct stmpe *stmpe, u8 reg, u8 length, u8 *values)
{
	int ret;

	mutex_lock(&stmpe->lock);
	ret = __stmpe_block_read(stmpe, reg, length, values);
	mutex_unlock(&stmpe->lock);

	return ret;
}
EXPORT_SYMBOL_GPL(stmpe_block_read);

/**
 * stmpe_block_write() - write multiple STMPE registers
 * @stmpe:	Device to write to
 * @reg:	First register
 * @length:	Number of registers
 * @values:	Values to write
 */
int stmpe_block_write(struct stmpe *stmpe, u8 reg, u8 length,
		      const u8 *values)
{
	int ret;

	mutex_lock(&stmpe->lock);
	ret = __stmpe_block_write(stmpe, reg, length, values);
	mutex_unlock(&stmpe->lock);

	return ret;
}
EXPORT_SYMBOL_GPL(stmpe_block_write);

/**
 * stmpe_set_altfunc()- set the alternate function for STMPE pins
 * @stmpe:	Device to configure
 * @pins:	Bitmask of pins to affect
 * @block:	block to enable alternate functions for
 *
 * @pins is assumed to have a bit set for each of the bits whose alternate
 * function is to be changed, numbered according to the GPIOXY numbers.
 *
 * If the GPIO module is not enabled, this function automatically enables it in
 * order to perform the change.
 */
int stmpe_set_altfunc(struct stmpe *stmpe, u32 pins, enum stmpe_block block)
{
	struct stmpe_variant_info *variant = stmpe->variant;
	u8 regaddr = stmpe->regs[STMPE_IDX_GPAFR_U_MSB];
	int af_bits = variant->af_bits;
	int numregs = DIV_ROUND_UP(stmpe->num_gpios * af_bits, 8);
	int mask = (1 << af_bits) - 1;
	u8 regs[8];
	int af, afperreg, ret;

	if (!variant->get_altfunc)
		return 0;

	afperreg = 8 / af_bits;
	mutex_lock(&stmpe->lock);

	ret = __stmpe_enable(stmpe, STMPE_BLOCK_GPIO);
	if (ret < 0)
		goto out;

	ret = __stmpe_block_read(stmpe, regaddr, numregs, regs);
	if (ret < 0)
		goto out;

	af = variant->get_altfunc(stmpe, block);

	while (pins) {
		int pin = __ffs(pins);
		int regoffset = numregs - (pin / afperreg) - 1;
		int pos = (pin % afperreg) * (8 / afperreg);

		regs[regoffset] &= ~(mask << pos);
		regs[regoffset] |= af << pos;

		pins &= ~(1 << pin);
	}

	ret = __stmpe_block_write(stmpe, regaddr, numregs, regs);

out:
	mutex_unlock(&stmpe->lock);
	return ret;
}
EXPORT_SYMBOL_GPL(stmpe_set_altfunc);

/*
 * GPIO (all variants)
 */

static struct resource stmpe_gpio_resources[] = {
	/* Start and end filled dynamically */
	{
		.flags	= IORESOURCE_IRQ,
	},
};

static const struct mfd_cell stmpe_gpio_cell = {
	.name		= "stmpe-gpio",
	.of_compatible	= "st,stmpe-gpio",
	.resources	= stmpe_gpio_resources,
	.num_resources	= ARRAY_SIZE(stmpe_gpio_resources),
};

static const struct mfd_cell stmpe_gpio_cell_noirq = {
	.name		= "stmpe-gpio",
	.of_compatible	= "st,stmpe-gpio",
	/* gpio cell resources consist of an irq only so no resources here */
};

/*
 * Keypad (1601, 2401, 2403)
 */

static struct resource stmpe_keypad_resources[] = {
	/* Start and