[1/1] w1: new driver. DS2431 chip.

[1/1] w1: new driver. DS2431 chip.

[Evgeniy Polyakov]

Signed-off-by: Bernhard Weirich <bernhard.weirich@riedel.net>
Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru>

--- linux-2.6.26.1/drivers/w1/w1_family.h	2008-07-18 14:51:32.000000000 +0200
+++ linux-2.6.26.5/drivers/w1/w1_family.h	2008-09-16 11:48:30.000000000 +0200
@@ -33,6 +33,7 @@
 #define W1_THERM_DS1822  	0x22
 #define W1_EEPROM_DS2433  	0x23
 #define W1_THERM_DS18B20 	0x28
+#define W1_EEPROM_DS2431	0x2D
 #define W1_FAMILY_DS2760	0x30
 
 #define MAXNAMELEN		32
--- linux-2.6.25.3/drivers/w1/slaves/w1_ds2431.c	1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.26.5/drivers/w1/slaves/w1_ds2431.c	2008-09-17 09:02:13.000000000 +0200
@@ -0,0 +1,318 @@
+/*
+ *	w1_DS2431.c - w1 family 2d (DS2431) driver
+ *
+ * Copyright (c) 2008 Bernhard Weirich <bernhard.weirich@riedel.net>
+ *
+ * Heavily inspired by w1_DS2433 driver from Ben Gardner <bgardner@wabtec.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 "../w1.h"
+#include "../w1_int.h"
+#include "../w1_family.h"
+
+#define W1_F2D_EEPROM_SIZE		128
+#define W1_F2D_PAGE_COUNT		4
+#define W1_F2D_PAGE_BITS		5
+#define W1_F2D_PAGE_SIZE		(1<<W1_F2D_PAGE_BITS)
+#define W1_F2D_PAGE_MASK		0x1F
+
+#define W1_F2D_SCRATCH_BITS  3
+#define W1_F2D_SCRATCH_SIZE  (1<<W1_F2D_SCRATCH_BITS)
+#define W1_F2D_SCRATCH_MASK  (W1_F2D_SCRATCH_SIZE-1)
+
+#define W1_F2D_READ_EEPROM	0xF0
+#define W1_F2D_WRITE_SCRATCH	0x0F
+#define W1_F2D_READ_SCRATCH	0xAA
+#define W1_F2D_COPY_SCRATCH	0x55
+
+
+#define W1_F2D_TPROG_MS		11
+
+#define W1_F2D_READ_RETRIES		10
+#define W1_F2D_READ_MAXLEN		8
+
+/**
+ * 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_f2d_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_F2D_READ_RETRIES times.
+ *
+ * count must not exceed W1_F2D_READ_MAXLEN.
+ */
+static int w1_f2d_readblock(struct w1_slave *sl, int off, int count, char *buf)
+{
+	u8 wrbuf[3];
+	u8 cmp[W1_F2D_READ_MAXLEN];
+	int tries = W1_F2D_READ_RETRIES;
+
+	do {
+		wrbuf[0] = W1_F2D_READ_EEPROM;
+		wrbuf[1] = off & 0xff;
+		wrbuf[2] = off >> 8;
+
+		if (w1_reset_select_slave(sl))
+			return -1;
+
+		w1_write_block(sl->master, wrbuf, 3);
+		w1_read_block(sl->master, buf, count);
+
+		if (w1_reset_select_slave(sl))
+			return -1;
+
+		w1_write_block(sl->master, wrbuf, 3);
+		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_F2D_READ_RETRIES);
+
+	return -1;
+}
+
+
+static ssize_t w1_f2d_read_bin(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_f2d_fix_count(off, count, W1_F2D_EEPROM_SIZE);
+	if (count == 0)
+		return 0;
+
+	mutex_lock(&sl->master->mutex);
+
+	/* read directly from the EEPROM in chunks of W1_F2D_READ_MAXLEN */
+	while (todo > 0) {
+		int block_read;
+
+		if (todo >= W1_F2D_READ_MAXLEN)
+			block_read = W1_F2D_READ_MAXLEN;
+		else
+			block_read = todo;
+
+		if (w1_f2d_readblock(sl, off, block_read, buf) < 0)
+			count = -EIO;
+
+		todo -= W1_F2D_READ_MAXLEN;
+		buf += W1_F2D_READ_MAXLEN;
+		off += W1_F2D_READ_MAXLEN;
+	}
+
+	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 aligned at W1_F2D_SCRATCH_SIZE bytes and
+ * must be W1_F2D_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_F2D_PAGE_SIZE - (addr & W1_F2D_PAGE_MASK))
+ * @param data	The data to write
+ * @return	0=Success -1=failure
+ */
+static int w1_f2d_write(struct w1_slave *sl, int addr, int len, const u8 *data)
+{
+	int tries = W1_F2D_READ_RETRIES;
+	u8 wrbuf[4];
+	u8 rdbuf[W1_F2D_SCRATCH_SIZE + 3];
+	u8 es = (addr + len - 1) % W1_F2D_SCRATCH_SIZE;
+
+retry:
+
+	/* Write the data to the scratchpad */
+	if (w1_reset_select_slave(sl))
+		return -1;
+
+	wrbuf[0] = W1_F2D_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_F2D_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)) {
+
+		if (--tries)
+			goto retry;
+
+		dev_err(&sl->dev,
+			"could not write to eeprom, scratchpad compare failed %d times\n",
+			W1_F2D_READ_RETRIES);
+
+		return -1;
+	}
+
+	/* Copy the scratchpad to EEPROM */
+	if (w1_reset_select_slave(sl))
+		return -1;
+
+	wrbuf[0] = W1_F2D_COPY_SCRATCH;
+	wrbuf[3] = es;
+	w1_write_block(sl->master, wrbuf, 4);
+
+	/* Sleep for tprog ms to wait for the write to complete */
+	msleep(W1_F2D_TPROG_MS);
+
+	/* Reset the bus to wake up the EEPROM  */
+	w1_reset_bus(sl->master);
+
+	return 0;
+}
+
+static ssize_t w1_f2d_write_bin(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_f2d_fix_count(off, count, W1_F2D_EEPROM_SIZE);
+	if (count == 0)
+		return 0;
+
+	mutex_lock(&sl->master->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_F2D_SCRATCH_SIZE || addr & W1_F2D_SCRATCH_MASK) {
+			char tmp[W1_F2D_SCRATCH_SIZE];
+
+			/* read the block and update the parts to be written */
+			if (w1_f2d_readblock(sl, addr & ~W1_F2D_SCRATCH_MASK,
+					W1_F2D_SCRATCH_SIZE, tmp)) {
+				count = -EIO;
+				goto out_up;
+			}
+
+			/* copy at most to the boundary of the PAGE or len */
+			copy = W1_F2D_SCRATCH_SIZE -
+				(addr & W1_F2D_SCRATCH_MASK);
+
+			if (copy > len)
+				copy = len;
+
+			memcpy(&tmp[addr & W1_F2D_SCRATCH_MASK], buf, copy);
+			if (w1_f2d_write(sl, addr & ~W1_F2D_SCRATCH_MASK,
+					W1_F2D_SCRATCH_SIZE, tmp) < 0) {
+				count = -EIO;
+				goto out_up;
+			}
+		} else {
+
+			copy = W1_F2D_SCRATCH_SIZE;
+			if (w1_f2d_write(sl, addr, copy, buf) < 0) {
+				count = -EIO;
+				goto out_up;
+			}
+		}
+		buf += copy;
+		addr += copy;
+		len -= copy;
+	}
+
+out_up:
+	mutex_unlock(&sl->master->mutex);
+
+	return count;
+}
+
+static struct bin_attribute w1_f2d_bin_attr = {
+	.attr = {
+		.name = "eeprom",
+		.mode = S_IRUGO | S_IWUSR,
+	},
+	.size = W1_F2D_EEPROM_SIZE,
+	.read = w1_f2d_read_bin,
+	.write = w1_f2d_write_bin,
+};
+
+static int w1_f2d_add_slave(struct w1_slave *sl)
+{
+	int err;
+	err = sysfs_create_bin_file(&sl->dev.kobj, &w1_f2d_bin_attr);
+
+	return err;
+}
+
+static void w1_f2d_remove_slave(struct w1_slave *sl)
+{
+	sysfs_remove_bin_file(&sl->dev.kobj, &w1_f2d_bin_attr);
+}
+
+static struct w1_family_ops w1_f2d_fops = {
+	.add_slave      = w1_f2d_add_slave,
+	.remove_slave   = w1_f2d_remove_slave,
+};
+
+static struct w1_family w1_family_2d = {
+	.fid = W1_EEPROM_DS2431,
+	.fops = &w1_f2d_fops,
+};
+
+static int __init w1_f2d_init(void)
+{
+	return w1_register_family(&w1_family_2d);
+}
+
+static void __exit w1_f2d_fini(void)
+{
+	w1_unregister_family(&w1_family_2d);
+}
+
+module_init(w1_f2d_init);
+module_exit(w1_f2d_fini);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Bernhard Weirich <bernhard.weirich@riedel.net>");
+MODULE_DESCRIPTION("w1 family 2d driver for DS2431, 1kb EEPROM");

-- 
	Evgeniy Polyakov

Re: [1/1] w1: new driver. DS2431 chip.

[Andrew Morton]

On Wed, 17 Sep 2008 19:49:29 +0400
Evgeniy Polyakov <johnpol@2ka.mipt.ru> wrote:

> Signed-off-by: Bernhard Weirich <bernhard.weirich@riedel.net>
> Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru>

This was authored by Bernhard, but the way in which it was sent claims
that it was authored by yourself.  Please add a From: line at the very
top of the changelog body to indicate authorship.

> --- linux-2.6.26.1/drivers/w1/w1_family.h	2008-07-18 14:51:32.000000000 +0200
> +++ linux-2.6.26.5/drivers/w1/w1_family.h	2008-09-16 11:48:30.000000000 +0200
> @@ -33,6 +33,7 @@
>  #define W1_THERM_DS1822  	0x22
>  #define W1_EEPROM_DS2433  	0x23
>  #define W1_THERM_DS18B20 	0x28
> +#define W1_EEPROM_DS2431	0x2D
>  #define W1_FAMILY_DS2760	0x30
>  
>  #define MAXNAMELEN		32
> --- linux-2.6.25.3/drivers/w1/slaves/w1_ds2431.c	1970-01-01 01:00:00.000000000 +0100
> +++ linux-2.6.26.5/drivers/w1/slaves/w1_ds2431.c	2008-09-17 09:02:13.000000000 +0200
> @@ -0,0 +1,318 @@
> +/*
> + *	w1_DS2431.c - w1 family 2d (DS2431) driver

case-insensitive filenames? ;)

> + * Copyright (c) 2008 Bernhard Weirich <bernhard.weirich@riedel.net>
> + *
> + * Heavily inspired by w1_DS2433 driver from Ben Gardner <bgardner@wabtec.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 "../w1.h"
> +#include "../w1_int.h"
> +#include "../w1_family.h"
> +
> +#define W1_F2D_EEPROM_SIZE		128
> +#define W1_F2D_PAGE_COUNT		4
> +#define W1_F2D_PAGE_BITS		5
> +#define W1_F2D_PAGE_SIZE		(1<<W1_F2D_PAGE_BITS)
> +#define W1_F2D_PAGE_MASK		0x1F
> +
> +#define W1_F2D_SCRATCH_BITS  3
> +#define W1_F2D_SCRATCH_SIZE  (1<<W1_F2D_SCRATCH_BITS)
> +#define W1_F2D_SCRATCH_MASK  (W1_F2D_SCRATCH_SIZE-1)
> +
> +#define W1_F2D_READ_EEPROM	0xF0
> +#define W1_F2D_WRITE_SCRATCH	0x0F
> +#define W1_F2D_READ_SCRATCH	0xAA
> +#define W1_F2D_COPY_SCRATCH	0x55
> +
> +
> +#define W1_F2D_TPROG_MS		11
> +
> +#define W1_F2D_READ_RETRIES		10
> +#define W1_F2D_READ_MAXLEN		8
> +
> +/**
> + * 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.
> + */

The driver has a number of comments whcih start with /**.  But that
pattern is specifically used to flag the presence of a kerneldoc-format
comment.  And these comments are in fact not in kerneldoc form.

> +/**
> + * Writes to the scratchpad and reads it back for verification.
> + * Then copies the scratchpad to EEPROM.
> + * The data must be aligned at W1_F2D_SCRATCH_SIZE bytes and
> + * must be W1_F2D_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_F2D_PAGE_SIZE - (addr & W1_F2D_PAGE_MASK))
> + * @param data	The data to write
> + * @return	0=Success -1=failure
> + */

This one looks a bit kerneldoc-like but actually isn't kerneldoc.


little fixes:

--- a/drivers/w1/slaves/w1_ds2431.c~w1-new-driver-ds2431-chip-fix
+++ a/drivers/w1/slaves/w1_ds2431.c
@@ -1,5 +1,5 @@
 /*
- *	w1_DS2431.c - w1 family 2d (DS2431) driver
+ * w1_ds2431.c - w1 family 2d (DS2431) driver
  *
  * Copyright (c) 2008 Bernhard Weirich <bernhard.weirich@riedel.net>
  *
@@ -41,7 +41,7 @@
 #define W1_F2D_READ_RETRIES		10
 #define W1_F2D_READ_MAXLEN		8
 
-/**
+/*
  * 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.
  */
@@ -56,7 +56,7 @@ static inline size_t w1_f2d_fix_count(lo
 	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_F2D_READ_RETRIES times.
@@ -88,8 +88,6 @@ static int w1_f2d_readblock(struct w1_sl
 
 		if (!memcmp(cmp, buf, count))
 			return 0;
-
-
 	} while (--tries);
 
 	dev_err(&sl->dev, "proof reading failed %d times\n",
@@ -98,7 +96,6 @@ static int w1_f2d_readblock(struct w1_sl
 	return -1;
 }
 
-
 static ssize_t w1_f2d_read_bin(struct kobject *kobj,
 			       struct bin_attribute *bin_attr,
 			       char *buf, loff_t off, size_t count)
@@ -134,7 +131,7 @@ static ssize_t w1_f2d_read_bin(struct ko
 	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_F2D_SCRATCH_SIZE bytes and
@@ -279,10 +276,7 @@ static struct bin_attribute w1_f2d_bin_a
 
 static int w1_f2d_add_slave(struct w1_slave *sl)
 {
-	int err;
-	err = sysfs_create_bin_file(&sl->dev.kobj, &w1_f2d_bin_attr);
-
-	return err;
+	return sysfs_create_bin_file(&sl->dev.kobj, &w1_f2d_bin_attr);
 }
 
 static void w1_f2d_remove_slave(struct w1_slave *sl)

Re: [1/1] w1: new driver. DS2431 chip.

[Evgeniy Polyakov]

On Wed, Sep 17, 2008 at 04:00:07PM -0700, Andrew Morton (akpm@linux-foundation.org) wrote:
> On Wed, 17 Sep 2008 19:49:29 +0400
> Evgeniy Polyakov <johnpol@2ka.mipt.ru> wrote:
> 
> > Signed-off-by: Bernhard Weirich <bernhard.weirich@riedel.net>
> > Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
> 
> This was authored by Bernhard, but the way in which it was sent claims
> that it was authored by yourself.  Please add a From: line at the very
> top of the changelog body to indicate authorship.

Ok, I see. Patch was definitely created by Bernhard, I just pointed to
couple of trivial cleanups. I saw you imported it into the tree with
your fixes, thanks a lot!

> > --- linux-2.6.25.3/drivers/w1/slaves/w1_ds2431.c	1970-01-01 01:00:00.000000000 +0100
> > +++ linux-2.6.26.5/drivers/w1/slaves/w1_ds2431.c	2008-09-17 09:02:13.000000000 +0200
> > @@ -0,0 +1,318 @@
> > +/*
> > + *	w1_DS2431.c - w1 family 2d (DS2431) driver
> 
> case-insensitive filenames? ;)

Fortunately only comment :)

> > +/**
> > + * 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.
> > + */
> 
> The driver has a number of comments whcih start with /**.  But that
> pattern is specifically used to flag the presence of a kerneldoc-format
> comment.  And these comments are in fact not in kerneldoc form.

I think we need to drop ** lines, since I did not convert kernel
comments into documentation, so would not be able to point to kerneldoc
(its doxygen iirc?) errors anyway.

-- 
	Evgeniy Polyakov

Re: [1/1] w1: new driver. DS2431 chip.

[Willy Tarreau]

On Wed, Sep 17, 2008 at 04:00:07PM -0700, Andrew Morton wrote:
> > +/*
> > + *	w1_DS2431.c - w1 family 2d (DS2431) driver
> 
> case-insensitive filenames? ;)

Also it would be kind to add one line indicating what this chip does.
I had to read till the last line to discover it's a 1kb EEPROM.

Willy