[PATCH] w1: Added DS2433 driver. (80895392) · Commits · e / devices / android_kernel_xiaomi_markw

drivers/w1/Kconfig

+7 −0

Original line number	Diff line number	Diff line
		@@ -54,4 +54,11 @@ config W1_SMEM
		Say Y here if you want to connect 1-wire
		simple 64bit memory rom(ds2401/ds2411/ds1990*) to you wire.

		config W1_DS2433
		tristate "4kb EEPROM family support (DS2433)"
		depends on W1
		help
		Say Y here if you want to use a 1-wire
		4kb EEPROM family device (DS2433).

		endmenu

drivers/w1/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -18,3 +18,4 @@ ds9490r-objs := dscore.o

		obj-$(CONFIG_W1_DS9490_BRIDGE) += ds_w1_bridge.o

		obj-$(CONFIG_W1_DS2433) += w1_ds2433.o

drivers/w1/w1_ds2433.c

0 → 100644

+222 −0

Original line number	Diff line number	Diff line
		/*
		* w1_ds2433.c - w1 family 23 (DS2433) driver
		*
		* Copyright (c) 2005 Ben Gardner <bgardner@wabtec.com>
		*
		* This program is free software; you can redistribute it and/or modify
		* it under the smems of the GNU General Public License as published by
		* the Free Software Foundation; version 2 of the License.
		*/

		#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 "w1.h"
		#include "w1_io.h"
		#include "w1_int.h"
		#include "w1_family.h"

		MODULE_LICENSE("GPL");
		MODULE_AUTHOR("Ben Gardner <bgardner@wabtec.com>");
		MODULE_DESCRIPTION("w1 family 23 driver for DS2433, 4kb EEPROM");

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

		#define W1_F23_READ_EEPROM 0xF0
		#define W1_F23_WRITE_SCRATCH 0x0F
		#define W1_F23_READ_SCRATCH 0xAA
		#define W1_F23_COPY_SCRATCH 0x55

		/**
		* Check the file size bounds and adjusts count as needed.
		* This may not be needed if the sysfs layer checks bounds.
		*/
		static inline size_t w1_f23_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 ssize_t w1_f23_read_bin(struct kobject kobj, char buf, loff_t off, size_t count)
		{
		struct w1_slave *sl = kobj_to_w1_slave(kobj);
		u8 wrbuf[3];

		if ((count = w1_f23_fix_count(off, count, W1_EEPROM_SIZE)) == 0)
		return 0;

		atomic_inc(&sl->refcnt);
		if (down_interruptible(&sl->master->mutex)) {
		count = 0;
		goto out_dec;
		}

		/* read directly from the EEPROM */
		if (w1_reset_select_slave(sl)) {
		count = -EIO;
		goto out_up;
		}

		wrbuf[0] = W1_F23_READ_EEPROM;
		wrbuf[1] = off & 0xff;
		wrbuf[2] = off >> 8;
		w1_write_block(sl->master, wrbuf, 3);
		w1_read_block(sl->master, buf, count);

		out_up:
		up(&sl->master->mutex);
		out_dec:
		atomic_dec(&sl->refcnt);

		return count;
		}

		/**
		* Writes to the scratchpad and reads it back for verification.
		* 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_f23_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;

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

		wrbuf[0] = W1_F23_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_F23_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_F23_COPY_SCRATCH;
		wrbuf[3] = es;
		w1_write_block(sl->master, wrbuf, 4);

		/* Sleep for 5 ms to wait for the write to complete */
		msleep(5);

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

		return 0;
		}

		static ssize_t w1_f23_write_bin(struct kobject kobj, char buf, loff_t off,
		size_t count)
		{
		struct w1_slave *sl = kobj_to_w1_slave(kobj);
		int addr, len, idx;

		if ((count = w1_f23_fix_count(off, count, W1_EEPROM_SIZE)) == 0)
		return 0;

		atomic_inc(&sl->refcnt);
		if (down_interruptible(&sl->master->mutex)) {
		count = 0;
		goto out_dec;
		}

		/* 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_f23_write(sl, addr, len, &buf[idx]) < 0) {
		count = -EIO;
		goto out_up;
		}
		idx += len;
		}

		out_up:
		up(&sl->master->mutex);
		out_dec:
		atomic_dec(&sl->refcnt);

		return count;
		}

		static struct bin_attribute w1_f23_bin_attr = {
		.attr = {
		.name = "eeprom",
		.mode = S_IRUGO \| S_IWUSR,
		.owner = THIS_MODULE,
		},
		.size = W1_EEPROM_SIZE,
		.read = w1_f23_read_bin,
		.write = w1_f23_write_bin,
		};

		static int w1_f23_add_slave(struct w1_slave *sl)
		{
		return sysfs_create_bin_file(&sl->dev.kobj, &w1_f23_bin_attr);
		}

		static void w1_f23_remove_slave(struct w1_slave *sl)
		{
		sysfs_remove_bin_file(&sl->dev.kobj, &w1_f23_bin_attr);
		}

		static struct w1_family_ops w1_f23_fops = {
		.add_slave = w1_f23_add_slave,
		.remove_slave = w1_f23_remove_slave,
		};

		static struct w1_family w1_family_23 = {
		.fid = W1_EEPROM_DS2433,
		.fops = &w1_f23_fops,
		};

		static int __init w1_f23_init(void)
		{
		return w1_register_family(&w1_family_23);
		}

		static void __exit w1_f23_fini(void)
		{
		w1_unregister_family(&w1_family_23);
		}

		module_init(w1_f23_init);
		module_exit(w1_f23_fini);