w1: new driver. DS2430 chip (c6bf3842) · Commits · 戴 / test

drivers/w1/slaves/Kconfig

+8 −0

Original line number	Diff line number	Diff line
		@@ -74,6 +74,14 @@ config W1_SLAVE_DS2805
		organized as 7 pages of 16 bytes each with 64bit
		unique number. Requires OverDrive Speed to talk to.

		config W1_SLAVE_DS2430
		tristate "256b EEPROM family support (DS2430)"
		help
		Say Y here if you want to use a 1-wire 256bit EEPROM
		family device (DS2430).
		This EEPROM is organized as one page of 32 bytes for random
		access.

		config W1_SLAVE_DS2431
		tristate "1kb EEPROM family support (DS2431)"
		help

drivers/w1/slaves/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -10,6 +10,7 @@ obj-$(CONFIG_W1_SLAVE_DS2408) += w1_ds2408.o
		obj-$(CONFIG_W1_SLAVE_DS2413) += w1_ds2413.o
		obj-$(CONFIG_W1_SLAVE_DS2406) += w1_ds2406.o
		obj-$(CONFIG_W1_SLAVE_DS2423) += w1_ds2423.o
		obj-$(CONFIG_W1_SLAVE_DS2430) += w1_ds2430.o
		obj-$(CONFIG_W1_SLAVE_DS2431) += w1_ds2431.o
		obj-$(CONFIG_W1_SLAVE_DS2805) += w1_ds2805.o
		obj-$(CONFIG_W1_SLAVE_DS2433) += w1_ds2433.o

drivers/w1/slaves/w1_ds2430.c

0 → 100644

+295 −0

Original line number	Diff line number	Diff line
		// SPDX-License-Identifier: GPL-2.0-only
		/*
		* w1_ds2430.c - w1 family 14 (DS2430) driver
		**
		* Copyright (c) 2019 Angelo Dureghello <angelo.dureghello@timesys.com>
		*
		* Cloned and modified from ds2431
		* Copyright (c) 2008 Bernhard Weirich <bernhard.weirich@riedel.net>
		*
		*/

		#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/w1.h>

		#define W1_EEPROM_DS2430 0x14

		#define W1_F14_EEPROM_SIZE 32
		#define W1_F14_PAGE_COUNT 1
		#define W1_F14_PAGE_BITS 5
		#define W1_F14_PAGE_SIZE (1 << W1_F14_PAGE_BITS)
		#define W1_F14_PAGE_MASK 0x1F

		#define W1_F14_SCRATCH_BITS 5
		#define W1_F14_SCRATCH_SIZE (1 << W1_F14_SCRATCH_BITS)
		#define W1_F14_SCRATCH_MASK (W1_F14_SCRATCH_SIZE-1)

		#define W1_F14_READ_EEPROM 0xF0
		#define W1_F14_WRITE_SCRATCH 0x0F
		#define W1_F14_READ_SCRATCH 0xAA
		#define W1_F14_COPY_SCRATCH 0x55
		#define W1_F14_VALIDATION_KEY 0xa5

		#define W1_F14_TPROG_MS 11
		#define W1_F14_READ_RETRIES 10
		#define W1_F14_READ_MAXLEN W1_F14_SCRATCH_SIZE

		/*
		* 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_f14_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;
		}

		/*
		* Read a block from W1 ROM two times and compares the results.
		* If they are equal they are returned, otherwise the read
		* is repeated W1_F14_READ_RETRIES times.
		*
		* count must not exceed W1_F14_READ_MAXLEN.
		*/
		static int w1_f14_readblock(struct w1_slave sl, int off, int count, char buf)
		{
		u8 wrbuf[2];
		u8 cmp[W1_F14_READ_MAXLEN];
		int tries = W1_F14_READ_RETRIES;

		do {
		wrbuf[0] = W1_F14_READ_EEPROM;
		wrbuf[1] = off & 0xff;

		if (w1_reset_select_slave(sl))
		return -1;

		w1_write_block(sl->master, wrbuf, 2);
		w1_read_block(sl->master, buf, count);

		if (w1_reset_select_slave(sl))
		return -1;

		w1_write_block(sl->master, wrbuf, 2);
		w1_read_block(sl->master, cmp, count);

		if (!memcmp(cmp, buf, count))
		return 0;
		} while (--tries);

		dev_err(&sl->dev, "proof reading failed %d times\n",
		W1_F14_READ_RETRIES);

		return -1;
		}

		static ssize_t eeprom_read(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 todo = count;

		count = w1_f14_fix_count(off, count, W1_F14_EEPROM_SIZE);
		if (count == 0)
		return 0;

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

		/* read directly from the EEPROM in chunks of W1_F14_READ_MAXLEN */
		while (todo > 0) {
		int block_read;

		if (todo >= W1_F14_READ_MAXLEN)
		block_read = W1_F14_READ_MAXLEN;
		else
		block_read = todo;

		if (w1_f14_readblock(sl, off, block_read, buf) < 0)
		count = -EIO;

		todo -= W1_F14_READ_MAXLEN;
		buf += W1_F14_READ_MAXLEN;
		off += W1_F14_READ_MAXLEN;
		}

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

		return count;
		}

		/*
		* Writes to the scratchpad and reads it back for verification.
		* Then copies the scratchpad to EEPROM.
		* The data must be aligned at W1_F14_SCRATCH_SIZE bytes and
		* must be W1_F14_SCRATCH_SIZE bytes long.
		* The master must be locked.
		*
		* @param sl The slave structure
		* @param addr Address for the write
		* @param len length must be <= (W1_F14_PAGE_SIZE - (addr & W1_F14_PAGE_MASK))
		* @param data The data to write
		* @return 0=Success -1=failure
		*/
		static int w1_f14_write(struct w1_slave sl, int addr, int len, const u8 data)
		{
		int tries = W1_F14_READ_RETRIES;
		u8 wrbuf[2];
		u8 rdbuf[W1_F14_SCRATCH_SIZE + 3];

		retry:

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

		wrbuf[0] = W1_F14_WRITE_SCRATCH;
		wrbuf[1] = addr & 0xff;

		w1_write_block(sl->master, wrbuf, 2);
		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_F14_READ_SCRATCH);
		w1_read_block(sl->master, rdbuf, len + 2);

		/*
		* Compare what was read against the data written
		* Note: on read scratchpad, device returns 2 bulk 0xff bytes,
		* to be discarded.
		*/
		if ((memcmp(data, &rdbuf[2], len) != 0)) {

		if (--tries)
		goto retry;

		dev_err(&sl->dev,
		"could not write to eeprom, scratchpad compare failed %d times\n",
		W1_F14_READ_RETRIES);

		return -1;
		}

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

		wrbuf[0] = W1_F14_COPY_SCRATCH;
		wrbuf[1] = W1_F14_VALIDATION_KEY;
		w1_write_block(sl->master, wrbuf, 2);

		/* Sleep for tprog ms to wait for the write to complete */
		msleep(W1_F14_TPROG_MS);

		/* Reset the bus to wake up the EEPROM */
		w1_reset_bus(sl->master);

		return 0;
		}

		static ssize_t eeprom_write(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;
		int copy;

		count = w1_f14_fix_count(off, count, W1_F14_EEPROM_SIZE);
		if (count == 0)
		return 0;

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

		/* Can only write data in blocks of the size of the scratchpad */
		addr = off;
		len = count;
		while (len > 0) {

		/* if len too short or addr not aligned */
		if (len < W1_F14_SCRATCH_SIZE \|\| addr & W1_F14_SCRATCH_MASK) {
		char tmp[W1_F14_SCRATCH_SIZE];

		/* read the block and update the parts to be written */
		if (w1_f14_readblock(sl, addr & ~W1_F14_SCRATCH_MASK,
		W1_F14_SCRATCH_SIZE, tmp)) {
		count = -EIO;
		goto out_up;
		}

		/* copy at most to the boundary of the PAGE or len */
		copy = W1_F14_SCRATCH_SIZE -
		(addr & W1_F14_SCRATCH_MASK);

		if (copy > len)
		copy = len;

		memcpy(&tmp[addr & W1_F14_SCRATCH_MASK], buf, copy);
		if (w1_f14_write(sl, addr & ~W1_F14_SCRATCH_MASK,
		W1_F14_SCRATCH_SIZE, tmp) < 0) {
		count = -EIO;
		goto out_up;
		}
		} else {

		copy = W1_F14_SCRATCH_SIZE;
		if (w1_f14_write(sl, addr, copy, buf) < 0) {
		count = -EIO;
		goto out_up;
		}
		}
		buf += copy;
		addr += copy;
		len -= copy;
		}

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

		return count;
		}

		static BIN_ATTR_RW(eeprom, W1_F14_EEPROM_SIZE);

		static struct bin_attribute *w1_f14_bin_attrs[] = {
		&bin_attr_eeprom,
		NULL,
		};

		static const struct attribute_group w1_f14_group = {
		.bin_attrs = w1_f14_bin_attrs,
		};

		static const struct attribute_group *w1_f14_groups[] = {
		&w1_f14_group,
		NULL,
		};

		static struct w1_family_ops w1_f14_fops = {
		.groups = w1_f14_groups,
		};

		static struct w1_family w1_family_14 = {
		.fid = W1_EEPROM_DS2430,
		.fops = &w1_f14_fops,
		};
		module_w1_family(w1_family_14);

		MODULE_AUTHOR("Angelo Dureghello <angelo.dureghello@timesys.com>");
		MODULE_DESCRIPTION("w1 family 14 driver for DS2430, 256kb EEPROM");
		MODULE_LICENSE("GPL");
		MODULE_ALIAS("w1-family-" __stringify(W1_EEPROM_DS2430));

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