w1: Add 1-wire slave device driver for DS28E04-100 (f19420c1) · Commits · e / devices / android_kernel_xiaomi_nabu

drivers/w1/slaves/Kconfig

+7 −0

Original line number	Diff line number	Diff line
		@@ -94,6 +94,13 @@ config W1_SLAVE_DS2781

		If you are unsure, say N.

		config W1_SLAVE_DS28E04
		tristate "4096-Bit Addressable 1-Wire EEPROM with PIO (DS28E04-100)"
		depends on W1
		help
		Say Y here if you want to use a 1-wire
		4kb EEPROM with PIO family device (DS28E04).

		config W1_SLAVE_BQ27000
		tristate "BQ27000 slave support"
		depends on W1

drivers/w1/slaves/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -12,3 +12,4 @@ obj-$(CONFIG_W1_SLAVE_DS2760) += w1_ds2760.o
		obj-$(CONFIG_W1_SLAVE_DS2780) += w1_ds2780.o
		obj-$(CONFIG_W1_SLAVE_DS2781) += w1_ds2781.o
		obj-$(CONFIG_W1_SLAVE_BQ27000) += w1_bq27000.o
		obj-$(CONFIG_W1_SLAVE_DS28E04) += w1_ds28e04.o

drivers/w1/slaves/w1_ds28e04.c

0 → 100644

+462 −0

Original line number	Diff line number	Diff line
		/*
		* w1_ds28e04.c - w1 family 1C (DS28E04) driver
		*
		* Copyright (c) 2012 Markus Franke <franke.m@sebakmt.com>
		*
		* This source code is licensed under the GNU General Public License,
		* Version 2. See the file COPYING for more details.
		*/

		#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/uaccess.h>

		#define CRC16_INIT 0
		#define CRC16_VALID 0xb001

		#include "../w1.h"
		#include "../w1_int.h"
		#include "../w1_family.h"

		MODULE_LICENSE("GPL");
		MODULE_AUTHOR("Markus Franke <franke.m@sebakmt.com>, <franm@hrz.tu-chemnitz.de>");
		MODULE_DESCRIPTION("w1 family 1C driver for DS28E04, 4kb EEPROM and PIO");

		/* Allow the strong pullup to be disabled, but default to enabled.
		* If it was disabled a parasite powered device might not get the required
		* current to copy the data from the scratchpad to EEPROM. If it is enabled parasite powered
		* devices have a better chance of getting the current required.
		*/
		static int w1_strong_pullup = 1;
		module_param_named(strong_pullup, w1_strong_pullup, int, 0);

		/* enable/disable CRC checking on DS28E04-100 memory accesses */
		static char w1_enable_crccheck = 1;

		#define W1_EEPROM_SIZE 512
		#define W1_PAGE_COUNT 16
		#define W1_PAGE_SIZE 32
		#define W1_PAGE_BITS 5
		#define W1_PAGE_MASK 0x1F

		#define W1_F1C_READ_EEPROM 0xF0
		#define W1_F1C_WRITE_SCRATCH 0x0F
		#define W1_F1C_READ_SCRATCH 0xAA
		#define W1_F1C_COPY_SCRATCH 0x55
		#define W1_F1C_ACCESS_WRITE 0x5A

		#define W1_1C_REG_LOGIC_STATE 0x220

		struct w1_f1C_data {
		u8 memory[W1_EEPROM_SIZE];
		u32 validcrc;
		};

		/**
		* Check the file size bounds and adjusts count as needed.
		* This would not be needed if the file size didn't reset to 0 after a write.
		*/
		static inline size_t w1_f1C_fix_count(loff_t off, size_t count, size_t size)
		{
		if (off > size)
		return 0;

		if ((off + count) > size)
		return (size - off);

		return count;
		}

		static int w1_f1C_refresh_block(struct w1_slave sl, struct w1_f1C_data data,
		int block)
		{
		u8 wrbuf[3];
		int off = block * W1_PAGE_SIZE;

		if (data->validcrc & (1 << block))
		return 0;

		if (w1_reset_select_slave(sl)) {
		data->validcrc = 0;
		return -EIO;
		}

		wrbuf[0] = W1_F1C_READ_EEPROM;
		wrbuf[1] = off & 0xff;
		wrbuf[2] = off >> 8;
		w1_write_block(sl->master, wrbuf, 3);
		w1_read_block(sl->master, &data->memory[off], W1_PAGE_SIZE);

		/* cache the block if the CRC is valid */
		if (crc16(CRC16_INIT, &data->memory[off], W1_PAGE_SIZE) == CRC16_VALID)
		data->validcrc \|= (1 << block);

		return 0;
		}

		static int w1_f1C_read(struct w1_slave sl, int addr, int len, char data)
		{
		u8 wrbuf[3];

		/* read directly from the EEPROM */
		if (w1_reset_select_slave(sl))
		return -EIO;

		wrbuf[0] = W1_F1C_READ_EEPROM;
		wrbuf[1] = addr & 0xff;
		wrbuf[2] = addr >> 8;

		w1_write_block(sl->master, wrbuf, sizeof(wrbuf));
		return w1_read_block(sl->master, data, len);
		}

		static ssize_t w1_f1C_read_bin(struct file filp, struct kobject kobj,
		struct bin_attribute *bin_attr,
		char *buf, loff_t off, size_t count)
		{
		struct w1_slave *sl = kobj_to_w1_slave(kobj);
		struct w1_f1C_data *data = sl->family_data;
		int i, min_page, max_page;

		if ((count = w1_f1C_fix_count(off, count, W1_EEPROM_SIZE)) == 0)
		return 0;

		mutex_lock(&sl->master->mutex);

		if(w1_enable_crccheck) {
		min_page = (off >> W1_PAGE_BITS);
		max_page = (off + count - 1) >> W1_PAGE_BITS;
		for (i = min_page; i <= max_page; i++) {
		if (w1_f1C_refresh_block(sl, data, i)) {
		count = -EIO;
		goto out_up;
		}
		}
		memcpy(buf, &data->memory[off], count);
		}
		else {
		count = w1_f1C_read(sl, off, count, buf);
		}

		out_up:
		mutex_unlock(&sl->master->mutex);

		return count;
		}

		/**
		* Writes to the scratchpad and reads it back for verification.
		* Then copies the scratchpad to EEPROM.
		* The data must be on one page.
		* The master must be locked.
		*
		* @param sl The slave structure
		* @param addr Address for the write
		* @param len length must be <= (W1_PAGE_SIZE - (addr & W1_PAGE_MASK))
		* @param data The data to write
		* @return 0=Success -1=failure
		*/
		static int w1_f1C_write(struct w1_slave sl, int addr, int len, const u8 data)
		{
		u8 wrbuf[4];
		u8 rdbuf[W1_PAGE_SIZE + 3];
		u8 es = (addr + len - 1) & 0x1f;
		unsigned int tm = 10;
		int i;
		struct w1_f1C_data *f1C = sl->family_data;

		/* Write the data to the scratchpad */
		if (w1_reset_select_slave(sl))
		return -1;

		wrbuf[0] = W1_F1C_WRITE_SCRATCH;
		wrbuf[1] = addr & 0xff;
		wrbuf[2] = addr >> 8;

		w1_write_block(sl->master, wrbuf, 3);
		w1_write_block(sl->master, data, len);

		/* Read the scratchpad and verify */
		if (w1_reset_select_slave(sl))
		return -1;

		w1_write_8(sl->master, W1_F1C_READ_SCRATCH);
		w1_read_block(sl->master, rdbuf, len + 3);

		/* Compare what was read against the data written */
		if ((rdbuf[0] != wrbuf[1]) \|\| (rdbuf[1] != wrbuf[2]) \|\|
		(rdbuf[2] != es) \|\| (memcmp(data, &rdbuf[3], len) != 0))
		return -1;

		/* Copy the scratchpad to EEPROM */
		if (w1_reset_select_slave(sl))
		return -1;

		wrbuf[0] = W1_F1C_COPY_SCRATCH;
		wrbuf[3] = es;

		for(i = 0; i < sizeof(wrbuf); ++i) {
		/* issue 10ms strong pullup (or delay) on the last byte for writing the data from the scratchpad to EEPROM */
		if(w1_strong_pullup && i == sizeof(wrbuf)-1)
		w1_next_pullup(sl->master, tm);

		w1_write_8(sl->master, wrbuf[i]);
		}

		if(!w1_strong_pullup)
		msleep(tm);

		if(w1_enable_crccheck) {
		/* invalidate cached data */
		f1C->validcrc &= ~(1 << (addr >> W1_PAGE_BITS));
		}

		/* Reset the bus to wake up the EEPROM (this may not be needed) */
		w1_reset_bus(sl->master);

		return 0;
		}

		static ssize_t w1_f1C_write_bin(struct file filp, struct kobject kobj,
		struct bin_attribute *bin_attr,
		char *buf, loff_t off, size_t count)

		{
		struct w1_slave *sl = kobj_to_w1_slave(kobj);
		int addr, len, idx;

		if ((count = w1_f1C_fix_count(off, count, W1_EEPROM_SIZE)) == 0)
		return 0;

		if(w1_enable_crccheck) {
		/* can only write full blocks in cached mode */
		if ((off & W1_PAGE_MASK) \|\| (count & W1_PAGE_MASK)) {
		dev_err(&sl->dev, "invalid offset/count off=%d cnt=%zd\n",
		(int)off, count);
		return -EINVAL;
		}

		/* make sure the block CRCs are valid */
		for (idx = 0; idx < count; idx += W1_PAGE_SIZE) {
		if (crc16(CRC16_INIT, &buf[idx], W1_PAGE_SIZE) != CRC16_VALID) {
		dev_err(&sl->dev, "bad CRC at offset %d\n", (int)off);
		return -EINVAL;
		}
		}
		}

		mutex_lock(&sl->master->mutex);

		/* Can only write data to one page at a time */
		idx = 0;
		while (idx < count) {
		addr = off + idx;
		len = W1_PAGE_SIZE - (addr & W1_PAGE_MASK);
		if (len > (count - idx))
		len = count - idx;

		if (w1_f1C_write(sl, addr, len, &buf[idx]) < 0) {
		count = -EIO;
		goto out_up;
		}
		idx += len;
		}

		out_up:
		mutex_unlock(&sl->master->mutex);

		return count;
		}

		static ssize_t w1_f1C_read_pio(struct file filp, struct kobject kobj,
		struct bin_attribute *bin_attr,
		char *buf, loff_t off, size_t count)

		{
		struct w1_slave *sl = kobj_to_w1_slave(kobj);
		int ret;

		/* check arguments */
		if(off != 0 \|\| count != 1 \|\| buf == NULL)
		return -EINVAL;

		mutex_lock(&sl->master->mutex);
		ret = w1_f1C_read(sl, W1_1C_REG_LOGIC_STATE, count, buf);
		mutex_unlock(&sl->master->mutex);

		return ret;
		}

		static ssize_t w1_f1C_write_pio(struct file filp, struct kobject kobj,
		struct bin_attribute *bin_attr,
		char *buf, loff_t off, size_t count)

		{
		struct w1_slave *sl = kobj_to_w1_slave(kobj);
		u8 wrbuf[3];
		u8 ack;

		/* check arguments */
		if(off != 0 \|\| count != 1 \|\| buf == NULL)
		return -EINVAL;

		mutex_lock(&sl->master->mutex);

		/* Write the PIO data */
		if (w1_reset_select_slave(sl))
		return -1;

		/* set bit 7..2 to value '1' */
		buf = buf \| 0xFC;

		wrbuf[0] = W1_F1C_ACCESS_WRITE;
		wrbuf[1] = *buf;
		wrbuf[2] = ~(*buf);
		w1_write_block(sl->master, wrbuf, 3);

		w1_read_block(sl->master, &ack, sizeof(ack));

		mutex_unlock(&sl->master->mutex);

		/* check for acknowledgement */
		if(ack != 0xAA) return -EIO;

		return count;
		}

		static ssize_t w1_f1C_show_crccheck(struct device dev, struct device_attribute attr,
		char *buf)
		{
		if(put_user(w1_enable_crccheck + 0x30, buf))
		return -EFAULT;

		return sizeof(w1_enable_crccheck);
		}

		static ssize_t w1_f1C_store_crccheck(struct device dev, struct device_attribute attr,
		const char *buf, size_t count)
		{
		char val;

		if(count != 1 \|\| !buf) return -EINVAL;

		if(get_user(val, buf))
		return -EFAULT;

		/* convert to decimal */
		val = val - 0x30;
		if(val != 0 && val != 1) return -EINVAL;

		/* set the new value */
		w1_enable_crccheck = val;

		return sizeof(w1_enable_crccheck);
		}

		#define NB_SYSFS_BIN_FILES 2
		static struct bin_attribute w1_f1C_bin_attr[NB_SYSFS_BIN_FILES] = {
		{
		.attr = {
		.name = "eeprom",
		.mode = S_IRUGO \| S_IWUSR,
		},
		.size = W1_EEPROM_SIZE,
		.read = w1_f1C_read_bin,
		.write = w1_f1C_write_bin,
		},
		{
		.attr = {
		.name = "pio",
		.mode = S_IRUGO \| S_IWUSR,
		},
		.size = 1,
		.read = w1_f1C_read_pio,
		.write = w1_f1C_write_pio,
		}
		};

		static DEVICE_ATTR(crccheck, S_IWUSR \| S_IRUGO, w1_f1C_show_crccheck, w1_f1C_store_crccheck);

		static int w1_f1C_add_slave(struct w1_slave *sl)
		{
		int err = 0;
		int i;
		struct w1_f1C_data *data = NULL;

		if(w1_enable_crccheck) {
		data = kzalloc(sizeof(struct w1_f1C_data), GFP_KERNEL);
		if (!data)
		return -ENOMEM;
		sl->family_data = data;
		}

		/* create binary sysfs attributes */
		for (i = 0; i < NB_SYSFS_BIN_FILES && !err; ++i)
		err = sysfs_create_bin_file(&sl->dev.kobj, &(w1_f1C_bin_attr[i]));

		if(err)
		goto out;

		/* create device attributes */
		err = device_create_file(&sl->dev, &dev_attr_crccheck);

		if(err) {
		/* remove binary sysfs attributes */
		for (i = 0; i < NB_SYSFS_BIN_FILES; ++i)
		sysfs_remove_bin_file(&sl->dev.kobj, &(w1_f1C_bin_attr[i]));
		}

		out:
		if(err) {
		if(w1_enable_crccheck)
		kfree(data);
		}

		return err;
		}

		static void w1_f1C_remove_slave(struct w1_slave *sl)
		{
		int i;

		if(w1_enable_crccheck) {
		kfree(sl->family_data);
		sl->family_data = NULL;
		}

		/* remove device attributes */
		device_remove_file(&sl->dev, &dev_attr_crccheck);

		/* remove binary sysfs attributes */
		for (i = 0; i < NB_SYSFS_BIN_FILES; ++i)
		sysfs_remove_bin_file(&sl->dev.kobj, &(w1_f1C_bin_attr[i]));
		}

		static struct w1_family_ops w1_f1C_fops = {
		.add_slave = w1_f1C_add_slave,
		.remove_slave = w1_f1C_remove_slave,
		};

		static struct w1_family w1_family_1C = {
		.fid = W1_FAMILY_DS28E04,
		.fops = &w1_f1C_fops,
		};

		static int __init w1_f1C_init(void)
		{
		return w1_register_family(&w1_family_1C);
		}

		static void __exit w1_f1C_fini(void)
		{
		w1_unregister_family(&w1_family_1C);
		}

		module_init(w1_f1C_init);
		module_exit(w1_f1C_fini);

drivers/w1/w1_family.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -30,6 +30,7 @@
		#define W1_FAMILY_SMEM_01 0x01
		#define W1_FAMILY_SMEM_81 0x81
		#define W1_THERM_DS18S20 0x10
		#define W1_FAMILY_DS28E04 0x1C
		#define W1_COUNTER_DS2423 0x1D
		#define W1_THERM_DS1822 0x22
		#define W1_EEPROM_DS2433 0x23