mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-21 16:29:59 +00:00
![Andy Shevchenko](/assets/img/avatar_default.png)
In few places the unnecessary explicit castings are being used. Drop them for good. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20210312134349.3472-1-andriy.shevchenko@linux.intel.com Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
173 lines
4 KiB
C
173 lines
4 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* BME680 - SPI Driver
|
|
*
|
|
* Copyright (C) 2018 Himanshu Jha <himanshujha199640@gmail.com>
|
|
*/
|
|
#include <linux/acpi.h>
|
|
#include <linux/module.h>
|
|
#include <linux/of.h>
|
|
#include <linux/regmap.h>
|
|
#include <linux/spi/spi.h>
|
|
|
|
#include "bme680.h"
|
|
|
|
struct bme680_spi_bus_context {
|
|
struct spi_device *spi;
|
|
u8 current_page;
|
|
};
|
|
|
|
/*
|
|
* In SPI mode there are only 7 address bits, a "page" register determines
|
|
* which part of the 8-bit range is active. This function looks at the address
|
|
* and writes the page selection bit if needed
|
|
*/
|
|
static int bme680_regmap_spi_select_page(
|
|
struct bme680_spi_bus_context *ctx, u8 reg)
|
|
{
|
|
struct spi_device *spi = ctx->spi;
|
|
int ret;
|
|
u8 buf[2];
|
|
u8 page = (reg & 0x80) ? 0 : 1; /* Page "1" is low range */
|
|
|
|
if (page == ctx->current_page)
|
|
return 0;
|
|
|
|
/*
|
|
* Data sheet claims we're only allowed to change bit 4, so we must do
|
|
* a read-modify-write on each and every page select
|
|
*/
|
|
buf[0] = BME680_REG_STATUS;
|
|
ret = spi_write_then_read(spi, buf, 1, buf + 1, 1);
|
|
if (ret < 0) {
|
|
dev_err(&spi->dev, "failed to set page %u\n", page);
|
|
return ret;
|
|
}
|
|
|
|
buf[0] = BME680_REG_STATUS;
|
|
if (page)
|
|
buf[1] |= BME680_SPI_MEM_PAGE_BIT;
|
|
else
|
|
buf[1] &= ~BME680_SPI_MEM_PAGE_BIT;
|
|
|
|
ret = spi_write(spi, buf, 2);
|
|
if (ret < 0) {
|
|
dev_err(&spi->dev, "failed to set page %u\n", page);
|
|
return ret;
|
|
}
|
|
|
|
ctx->current_page = page;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int bme680_regmap_spi_write(void *context, const void *data,
|
|
size_t count)
|
|
{
|
|
struct bme680_spi_bus_context *ctx = context;
|
|
struct spi_device *spi = ctx->spi;
|
|
int ret;
|
|
u8 buf[2];
|
|
|
|
memcpy(buf, data, 2);
|
|
|
|
ret = bme680_regmap_spi_select_page(ctx, buf[0]);
|
|
if (ret)
|
|
return ret;
|
|
|
|
/*
|
|
* The SPI register address (= full register address without bit 7)
|
|
* and the write command (bit7 = RW = '0')
|
|
*/
|
|
buf[0] &= ~0x80;
|
|
|
|
return spi_write(spi, buf, 2);
|
|
}
|
|
|
|
static int bme680_regmap_spi_read(void *context, const void *reg,
|
|
size_t reg_size, void *val, size_t val_size)
|
|
{
|
|
struct bme680_spi_bus_context *ctx = context;
|
|
struct spi_device *spi = ctx->spi;
|
|
int ret;
|
|
u8 addr = *(const u8 *)reg;
|
|
|
|
ret = bme680_regmap_spi_select_page(ctx, addr);
|
|
if (ret)
|
|
return ret;
|
|
|
|
addr |= 0x80; /* bit7 = RW = '1' */
|
|
|
|
return spi_write_then_read(spi, &addr, 1, val, val_size);
|
|
}
|
|
|
|
static struct regmap_bus bme680_regmap_bus = {
|
|
.write = bme680_regmap_spi_write,
|
|
.read = bme680_regmap_spi_read,
|
|
.reg_format_endian_default = REGMAP_ENDIAN_BIG,
|
|
.val_format_endian_default = REGMAP_ENDIAN_BIG,
|
|
};
|
|
|
|
static int bme680_spi_probe(struct spi_device *spi)
|
|
{
|
|
const struct spi_device_id *id = spi_get_device_id(spi);
|
|
struct bme680_spi_bus_context *bus_context;
|
|
struct regmap *regmap;
|
|
int ret;
|
|
|
|
spi->bits_per_word = 8;
|
|
ret = spi_setup(spi);
|
|
if (ret < 0) {
|
|
dev_err(&spi->dev, "spi_setup failed!\n");
|
|
return ret;
|
|
}
|
|
|
|
bus_context = devm_kzalloc(&spi->dev, sizeof(*bus_context), GFP_KERNEL);
|
|
if (!bus_context)
|
|
return -ENOMEM;
|
|
|
|
bus_context->spi = spi;
|
|
bus_context->current_page = 0xff; /* Undefined on warm boot */
|
|
|
|
regmap = devm_regmap_init(&spi->dev, &bme680_regmap_bus,
|
|
bus_context, &bme680_regmap_config);
|
|
if (IS_ERR(regmap)) {
|
|
dev_err(&spi->dev, "Failed to register spi regmap %ld\n", PTR_ERR(regmap));
|
|
return PTR_ERR(regmap);
|
|
}
|
|
|
|
return bme680_core_probe(&spi->dev, regmap, id->name);
|
|
}
|
|
|
|
static const struct spi_device_id bme680_spi_id[] = {
|
|
{"bme680", 0},
|
|
{},
|
|
};
|
|
MODULE_DEVICE_TABLE(spi, bme680_spi_id);
|
|
|
|
static const struct acpi_device_id bme680_acpi_match[] = {
|
|
{"BME0680", 0},
|
|
{},
|
|
};
|
|
MODULE_DEVICE_TABLE(acpi, bme680_acpi_match);
|
|
|
|
static const struct of_device_id bme680_of_spi_match[] = {
|
|
{ .compatible = "bosch,bme680", },
|
|
{},
|
|
};
|
|
MODULE_DEVICE_TABLE(of, bme680_of_spi_match);
|
|
|
|
static struct spi_driver bme680_spi_driver = {
|
|
.driver = {
|
|
.name = "bme680_spi",
|
|
.acpi_match_table = ACPI_PTR(bme680_acpi_match),
|
|
.of_match_table = bme680_of_spi_match,
|
|
},
|
|
.probe = bme680_spi_probe,
|
|
.id_table = bme680_spi_id,
|
|
};
|
|
module_spi_driver(bme680_spi_driver);
|
|
|
|
MODULE_AUTHOR("Himanshu Jha <himanshujha199640@gmail.com>");
|
|
MODULE_DESCRIPTION("Bosch BME680 SPI driver");
|
|
MODULE_LICENSE("GPL v2");
|