cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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stmpe-spi.c (3618B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * ST Microelectronics MFD: stmpe's spi client specific driver
      4 *
      5 * Copyright (C) ST Microelectronics SA 2011
      6 *
      7 * Author: Viresh Kumar <vireshk@kernel.org> for ST Microelectronics
      8 */
      9
     10#include <linux/spi/spi.h>
     11#include <linux/interrupt.h>
     12#include <linux/kernel.h>
     13#include <linux/module.h>
     14#include <linux/of.h>
     15#include <linux/types.h>
     16#include "stmpe.h"
     17
     18#define READ_CMD	(1 << 7)
     19
     20static int spi_reg_read(struct stmpe *stmpe, u8 reg)
     21{
     22	struct spi_device *spi = stmpe->client;
     23	int status = spi_w8r16(spi, reg | READ_CMD);
     24
     25	return (status < 0) ? status : status >> 8;
     26}
     27
     28static int spi_reg_write(struct stmpe *stmpe, u8 reg, u8 val)
     29{
     30	struct spi_device *spi = stmpe->client;
     31	u16 cmd = (val << 8) | reg;
     32
     33	return spi_write(spi, (const u8 *)&cmd, 2);
     34}
     35
     36static int spi_block_read(struct stmpe *stmpe, u8 reg, u8 length, u8 *values)
     37{
     38	int ret, i;
     39
     40	for (i = 0; i < length; i++) {
     41		ret = spi_reg_read(stmpe, reg + i);
     42		if (ret < 0)
     43			return ret;
     44		*(values + i) = ret;
     45	}
     46
     47	return 0;
     48}
     49
     50static int spi_block_write(struct stmpe *stmpe, u8 reg, u8 length,
     51		const u8 *values)
     52{
     53	int ret = 0, i;
     54
     55	for (i = length; i > 0; i--, reg++) {
     56		ret = spi_reg_write(stmpe, reg, *(values + i - 1));
     57		if (ret < 0)
     58			return ret;
     59	}
     60
     61	return ret;
     62}
     63
     64static void spi_init(struct stmpe *stmpe)
     65{
     66	struct spi_device *spi = stmpe->client;
     67
     68	spi->bits_per_word = 8;
     69
     70	/* This register is only present for stmpe811 */
     71	if (stmpe->variant->id_val == 0x0811)
     72		spi_reg_write(stmpe, STMPE811_REG_SPI_CFG, spi->mode);
     73
     74	if (spi_setup(spi) < 0)
     75		dev_dbg(&spi->dev, "spi_setup failed\n");
     76}
     77
     78static struct stmpe_client_info spi_ci = {
     79	.read_byte = spi_reg_read,
     80	.write_byte = spi_reg_write,
     81	.read_block = spi_block_read,
     82	.write_block = spi_block_write,
     83	.init = spi_init,
     84};
     85
     86static int
     87stmpe_spi_probe(struct spi_device *spi)
     88{
     89	const struct spi_device_id *id = spi_get_device_id(spi);
     90
     91	/* don't exceed max specified rate - 1MHz - Limitation of STMPE */
     92	if (spi->max_speed_hz > 1000000) {
     93		dev_dbg(&spi->dev, "f(sample) %d KHz?\n",
     94				(spi->max_speed_hz/1000));
     95		return -EINVAL;
     96	}
     97
     98	spi_ci.irq = spi->irq;
     99	spi_ci.client = spi;
    100	spi_ci.dev = &spi->dev;
    101
    102	return stmpe_probe(&spi_ci, id->driver_data);
    103}
    104
    105static void stmpe_spi_remove(struct spi_device *spi)
    106{
    107	struct stmpe *stmpe = spi_get_drvdata(spi);
    108
    109	stmpe_remove(stmpe);
    110}
    111
    112static const struct of_device_id stmpe_spi_of_match[] = {
    113	{ .compatible = "st,stmpe610", },
    114	{ .compatible = "st,stmpe801", },
    115	{ .compatible = "st,stmpe811", },
    116	{ .compatible = "st,stmpe1601", },
    117	{ .compatible = "st,stmpe2401", },
    118	{ .compatible = "st,stmpe2403", },
    119	{ /* sentinel */ },
    120};
    121MODULE_DEVICE_TABLE(of, stmpe_spi_of_match);
    122
    123static const struct spi_device_id stmpe_spi_id[] = {
    124	{ "stmpe610", STMPE610 },
    125	{ "stmpe801", STMPE801 },
    126	{ "stmpe811", STMPE811 },
    127	{ "stmpe1601", STMPE1601 },
    128	{ "stmpe2401", STMPE2401 },
    129	{ "stmpe2403", STMPE2403 },
    130	{ }
    131};
    132MODULE_DEVICE_TABLE(spi, stmpe_id);
    133
    134static struct spi_driver stmpe_spi_driver = {
    135	.driver = {
    136		.name	= "stmpe-spi",
    137		.of_match_table = of_match_ptr(stmpe_spi_of_match),
    138#ifdef CONFIG_PM
    139		.pm	= &stmpe_dev_pm_ops,
    140#endif
    141	},
    142	.probe		= stmpe_spi_probe,
    143	.remove		= stmpe_spi_remove,
    144	.id_table	= stmpe_spi_id,
    145};
    146
    147static int __init stmpe_init(void)
    148{
    149	return spi_register_driver(&stmpe_spi_driver);
    150}
    151subsys_initcall(stmpe_init);
    152
    153static void __exit stmpe_exit(void)
    154{
    155	spi_unregister_driver(&stmpe_spi_driver);
    156}
    157module_exit(stmpe_exit);
    158
    159MODULE_LICENSE("GPL v2");
    160MODULE_DESCRIPTION("STMPE MFD SPI Interface Driver");
    161MODULE_AUTHOR("Viresh Kumar <vireshk@kernel.org>");