diff options
author | Thomas Bogendoerfer <tbogendoerfer@suse.de> | 2019-08-31 11:26:22 +0300 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-09-04 15:34:31 +0300 |
commit | 25ec8710d9c2cd4d0446ac60a72d388000d543e6 (patch) | |
tree | 64478352790d934b965629443babb399c418d74c /drivers/w1/slaves | |
parent | 74ded38a8e185b57a4362787815c353ac595013c (diff) | |
download | linux-25ec8710d9c2cd4d0446ac60a72d388000d543e6.tar.xz |
w1: add DS2501, DS2502, DS2505 EPROM device driver
Add a 1-Wire slave driver to support DS250x EPROM deivces. This
slave driver attaches the devices to the NVMEM subsystem for
an easy in-kernel usage.
Signed-off-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
Link: https://lore.kernel.org/r/20190831082623.15627-3-tbogendoerfer@suse.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/w1/slaves')
-rw-r--r-- | drivers/w1/slaves/Kconfig | 6 | ||||
-rw-r--r-- | drivers/w1/slaves/Makefile | 1 | ||||
-rw-r--r-- | drivers/w1/slaves/w1_ds250x.c | 290 |
3 files changed, 297 insertions, 0 deletions
diff --git a/drivers/w1/slaves/Kconfig b/drivers/w1/slaves/Kconfig index 37aaad26b373..ebed495b9e69 100644 --- a/drivers/w1/slaves/Kconfig +++ b/drivers/w1/slaves/Kconfig @@ -101,6 +101,12 @@ config W1_SLAVE_DS2438 Say Y here if you want to use a 1-wire DS2438 Smart Battery Monitor device support +config W1_SLAVE_DS250X + tristate "512b/1kb/16kb EPROM family support" + help + Say Y here if you want to use a 1-wire + 512b/1kb/16kb EPROM family device (DS250x). + config W1_SLAVE_DS2780 tristate "Dallas 2780 battery monitor chip" help diff --git a/drivers/w1/slaves/Makefile b/drivers/w1/slaves/Makefile index eab29f151413..8e9655eaa478 100644 --- a/drivers/w1/slaves/Makefile +++ b/drivers/w1/slaves/Makefile @@ -14,6 +14,7 @@ obj-$(CONFIG_W1_SLAVE_DS2431) += w1_ds2431.o obj-$(CONFIG_W1_SLAVE_DS2805) += w1_ds2805.o obj-$(CONFIG_W1_SLAVE_DS2433) += w1_ds2433.o obj-$(CONFIG_W1_SLAVE_DS2438) += w1_ds2438.o +obj-$(CONFIG_W1_SLAVE_DS250X) += w1_ds250x.o obj-$(CONFIG_W1_SLAVE_DS2780) += w1_ds2780.o obj-$(CONFIG_W1_SLAVE_DS2781) += w1_ds2781.o obj-$(CONFIG_W1_SLAVE_DS28E04) += w1_ds28e04.o diff --git a/drivers/w1/slaves/w1_ds250x.c b/drivers/w1/slaves/w1_ds250x.c new file mode 100644 index 000000000000..e507117444d8 --- /dev/null +++ b/drivers/w1/slaves/w1_ds250x.c @@ -0,0 +1,290 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * w1_ds250x.c - w1 family 09/0b/89/91 (DS250x) driver + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/device.h> +#include <linux/types.h> +#include <linux/delay.h> +#include <linux/slab.h> +#include <linux/crc16.h> + +#include <linux/w1.h> +#include <linux/nvmem-provider.h> + +#define W1_DS2501_UNW_FAMILY 0x91 +#define W1_DS2501_SIZE 64 + +#define W1_DS2502_FAMILY 0x09 +#define W1_DS2502_UNW_FAMILY 0x89 +#define W1_DS2502_SIZE 128 + +#define W1_DS2505_FAMILY 0x0b +#define W1_DS2505_SIZE 2048 + +#define W1_PAGE_SIZE 32 + +#define W1_EXT_READ_MEMORY 0xA5 +#define W1_READ_DATA_CRC 0xC3 + +#define OFF2PG(off) ((off) / W1_PAGE_SIZE) + +#define CRC16_INIT 0 +#define CRC16_VALID 0xb001 + +struct w1_eprom_data { + size_t size; + int (*read)(struct w1_slave *sl, int pageno); + u8 eprom[W1_DS2505_SIZE]; + DECLARE_BITMAP(page_present, W1_DS2505_SIZE / W1_PAGE_SIZE); + char nvmem_name[64]; +}; + +static int w1_ds2502_read_page(struct w1_slave *sl, int pageno) +{ + struct w1_eprom_data *data = sl->family_data; + int pgoff = pageno * W1_PAGE_SIZE; + int ret = -EIO; + u8 buf[3]; + u8 crc8; + + if (test_bit(pageno, data->page_present)) + return 0; /* page already present */ + + mutex_lock(&sl->master->bus_mutex); + + if (w1_reset_select_slave(sl)) + goto err; + + buf[0] = W1_READ_DATA_CRC; + buf[1] = pgoff & 0xff; + buf[2] = pgoff >> 8; + w1_write_block(sl->master, buf, 3); + + crc8 = w1_read_8(sl->master); + if (w1_calc_crc8(buf, 3) != crc8) + goto err; + + w1_read_block(sl->master, &data->eprom[pgoff], W1_PAGE_SIZE); + + crc8 = w1_read_8(sl->master); + if (w1_calc_crc8(&data->eprom[pgoff], W1_PAGE_SIZE) != crc8) + goto err; + + set_bit(pageno, data->page_present); /* mark page present */ + ret = 0; +err: + mutex_unlock(&sl->master->bus_mutex); + return ret; +} + +static int w1_ds2505_read_page(struct w1_slave *sl, int pageno) +{ + struct w1_eprom_data *data = sl->family_data; + int redir_retries = 16; + int pgoff, epoff; + int ret = -EIO; + u8 buf[6]; + u8 redir; + u16 crc; + + if (test_bit(pageno, data->page_present)) + return 0; /* page already present */ + + epoff = pgoff = pageno * W1_PAGE_SIZE; + mutex_lock(&sl->master->bus_mutex); + +retry: + if (w1_reset_select_slave(sl)) + goto err; + + buf[0] = W1_EXT_READ_MEMORY; + buf[1] = pgoff & 0xff; + buf[2] = pgoff >> 8; + w1_write_block(sl->master, buf, 3); + w1_read_block(sl->master, buf + 3, 3); /* redir, crc16 */ + redir = buf[3]; + crc = crc16(CRC16_INIT, buf, 6); + + if (crc != CRC16_VALID) + goto err; + + + if (redir != 0xff) { + redir_retries--; + if (redir_retries < 0) + goto err; + + pgoff = (redir ^ 0xff) * W1_PAGE_SIZE; + goto retry; + } + + w1_read_block(sl->master, &data->eprom[epoff], W1_PAGE_SIZE); + w1_read_block(sl->master, buf, 2); /* crc16 */ + crc = crc16(CRC16_INIT, &data->eprom[epoff], W1_PAGE_SIZE); + crc = crc16(crc, buf, 2); + + if (crc != CRC16_VALID) + goto err; + + set_bit(pageno, data->page_present); + ret = 0; +err: + mutex_unlock(&sl->master->bus_mutex); + return ret; +} + +static int w1_nvmem_read(void *priv, unsigned int off, void *buf, size_t count) +{ + struct w1_slave *sl = priv; + struct w1_eprom_data *data = sl->family_data; + size_t eprom_size = data->size; + int ret; + int i; + + if (off > eprom_size) + return -EINVAL; + + if ((off + count) > eprom_size) + count = eprom_size - off; + + i = OFF2PG(off); + do { + ret = data->read(sl, i++); + if (ret < 0) + return ret; + } while (i < OFF2PG(off + count)); + + memcpy(buf, &data->eprom[off], count); + return 0; +} + +static int w1_eprom_add_slave(struct w1_slave *sl) +{ + struct w1_eprom_data *data; + struct nvmem_device *nvmem; + struct nvmem_config nvmem_cfg = { + .dev = &sl->dev, + .reg_read = w1_nvmem_read, + .type = NVMEM_TYPE_OTP, + .read_only = true, + .word_size = 1, + .priv = sl, + .id = -1 + }; + + data = devm_kzalloc(&sl->dev, sizeof(struct w1_eprom_data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + sl->family_data = data; + switch (sl->family->fid) { + case W1_DS2501_UNW_FAMILY: + data->size = W1_DS2501_SIZE; + data->read = w1_ds2502_read_page; + break; + case W1_DS2502_FAMILY: + case W1_DS2502_UNW_FAMILY: + data->size = W1_DS2502_SIZE; + data->read = w1_ds2502_read_page; + break; + case W1_DS2505_FAMILY: + data->size = W1_DS2505_SIZE; + data->read = w1_ds2505_read_page; + break; + } + + if (sl->master->bus_master->dev_id) + snprintf(data->nvmem_name, sizeof(data->nvmem_name), + "%s-%02x-%012llx", + sl->master->bus_master->dev_id, sl->reg_num.family, + (unsigned long long)sl->reg_num.id); + else + snprintf(data->nvmem_name, sizeof(data->nvmem_name), + "%02x-%012llx", + sl->reg_num.family, + (unsigned long long)sl->reg_num.id); + + nvmem_cfg.name = data->nvmem_name; + nvmem_cfg.size = data->size; + + nvmem = devm_nvmem_register(&sl->dev, &nvmem_cfg); + return PTR_ERR_OR_ZERO(nvmem); +} + +static struct w1_family_ops w1_eprom_fops = { + .add_slave = w1_eprom_add_slave, +}; + +static struct w1_family w1_family_09 = { + .fid = W1_DS2502_FAMILY, + .fops = &w1_eprom_fops, +}; + +static struct w1_family w1_family_0b = { + .fid = W1_DS2505_FAMILY, + .fops = &w1_eprom_fops, +}; + +static struct w1_family w1_family_89 = { + .fid = W1_DS2502_UNW_FAMILY, + .fops = &w1_eprom_fops, +}; + +static struct w1_family w1_family_91 = { + .fid = W1_DS2501_UNW_FAMILY, + .fops = &w1_eprom_fops, +}; + +static int __init w1_ds250x_init(void) +{ + int err; + + err = w1_register_family(&w1_family_09); + if (err) + return err; + + err = w1_register_family(&w1_family_0b); + if (err) + goto err_0b; + + err = w1_register_family(&w1_family_89); + if (err) + goto err_89; + + err = w1_register_family(&w1_family_91); + if (err) + goto err_91; + + return 0; + +err_91: + w1_unregister_family(&w1_family_89); +err_89: + w1_unregister_family(&w1_family_0b); +err_0b: + w1_unregister_family(&w1_family_09); + return err; +} + +static void __exit w1_ds250x_exit(void) +{ + w1_unregister_family(&w1_family_09); + w1_unregister_family(&w1_family_0b); + w1_unregister_family(&w1_family_89); + w1_unregister_family(&w1_family_91); +} + +module_init(w1_ds250x_init); +module_exit(w1_ds250x_exit); + +MODULE_AUTHOR("Thomas Bogendoerfer <tbogendoerfe@suse.de>"); +MODULE_DESCRIPTION("w1 family driver for DS250x Add Only Memory"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("w1-family-" __stringify(W1_DS2502_FAMILY)); +MODULE_ALIAS("w1-family-" __stringify(W1_DS2505_FAMILY)); +MODULE_ALIAS("w1-family-" __stringify(W1_DS2501_UNW_FAMILY)); +MODULE_ALIAS("w1-family-" __stringify(W1_DS2502_UNW_FAMILY)); |