drivers: w1: Add 1w slave driver for DS28E05 EEPROM
authorAndrew Worsley <amworsley@gmail.com>
Sun, 27 Aug 2017 11:34:23 +0000 (21:34 +1000)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Mon, 28 Aug 2017 15:23:29 +0000 (17:23 +0200)
Add a one wire driver for the DS28E05 one wire slave chip. This chip
requires OverDrive support to talk to it.

Signed-off-by: Andrew Worsley <amworsley@gmail.com>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/w1/slaves/Kconfig
drivers/w1/slaves/Makefile
drivers/w1/slaves/w1_ds2805.c [new file with mode: 0644]
drivers/w1/w1.c

index fb68465908f21371a31f0656d101996d568cb26c..bb4d7ed2ce55b3cbcc1a6fe9c3c555ad64694384 100644 (file)
@@ -65,6 +65,14 @@ config W1_SLAVE_DS2423
          Say Y here if you want to use a 1-wire
          counter family device (DS2423).
 
+config W1_SLAVE_DS2805
+       tristate "112-byte EEPROM support (DS28E05)"
+       help
+         Say Y here if you want to use a 1-wire
+         is a 112-byte user-programmable EEPROM is
+          organized as 7 pages of 16 bytes each with 64bit
+          unique number. Requires OverDrive Speed to talk to.
+
 config W1_SLAVE_DS2431
        tristate "1kb EEPROM family support (DS2431)"
        help
index 54c63e4203024d2dcc34dd69f31665f19f01aa9e..4622d8fed362fce118826682331e4b8486c438cd 100644 (file)
@@ -10,6 +10,7 @@ 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_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_DS2760)  += w1_ds2760.o
diff --git a/drivers/w1/slaves/w1_ds2805.c b/drivers/w1/slaves/w1_ds2805.c
new file mode 100644 (file)
index 0000000..29348d2
--- /dev/null
@@ -0,0 +1,313 @@
+/*
+ * w1_ds2805 - w1 family 0d (DS28E05) driver
+ *
+ * Copyright (c) 2016 Andrew Worsley amworsley@gmail.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/w1.h>
+
+#define W1_EEPROM_DS2805       0x0D
+
+#define W1_F0D_EEPROM_SIZE             128
+#define W1_F0D_PAGE_BITS               3
+#define W1_F0D_PAGE_SIZE               (1<<W1_F0D_PAGE_BITS)
+#define W1_F0D_PAGE_MASK               0x0F
+
+#define W1_F0D_SCRATCH_BITS  1
+#define W1_F0D_SCRATCH_SIZE  (1<<W1_F0D_SCRATCH_BITS)
+#define W1_F0D_SCRATCH_MASK  (W1_F0D_SCRATCH_SIZE-1)
+
+#define W1_F0D_READ_EEPROM     0xF0
+#define W1_F0D_WRITE_EEPROM    0x55
+#define W1_F0D_RELEASE         0xFF
+
+#define W1_F0D_CS_OK           0xAA /* Chip Status Ok */
+
+#define W1_F0D_TPROG_MS                16
+
+#define W1_F0D_READ_RETRIES            10
+#define W1_F0D_READ_MAXLEN             W1_F0D_EEPROM_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_f0d_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_F0D_READ_RETRIES times.
+ *
+ * count must not exceed W1_F0D_READ_MAXLEN.
+ */
+static int w1_f0d_readblock(struct w1_slave *sl, int off, int count, char *buf)
+{
+       u8 wrbuf[3];
+       u8 cmp[W1_F0D_READ_MAXLEN];
+       int tries = W1_F0D_READ_RETRIES;
+
+       do {
+               wrbuf[0] = W1_F0D_READ_EEPROM;
+               wrbuf[1] = off & 0x7f;
+               wrbuf[2] = 0;
+
+               if (w1_reset_select_slave(sl))
+                       return -1;
+
+               w1_write_block(sl->master, wrbuf, sizeof(wrbuf));
+               w1_read_block(sl->master, buf, count);
+
+               if (w1_reset_select_slave(sl))
+                       return -1;
+
+               w1_write_block(sl->master, wrbuf, sizeof(wrbuf));
+               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_F0D_READ_RETRIES);
+
+       return -1;
+}
+
+static ssize_t w1_f0d_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);
+       int todo = count;
+
+       count = w1_f0d_fix_count(off, count, W1_F0D_EEPROM_SIZE);
+       if (count == 0)
+               return 0;
+
+       mutex_lock(&sl->master->mutex);
+
+       /* read directly from the EEPROM in chunks of W1_F0D_READ_MAXLEN */
+       while (todo > 0) {
+               int block_read;
+
+               if (todo >= W1_F0D_READ_MAXLEN)
+                       block_read = W1_F0D_READ_MAXLEN;
+               else
+                       block_read = todo;
+
+               if (w1_f0d_readblock(sl, off, block_read, buf) < 0) {
+                       count = -EIO;
+                       break;
+               }
+
+               todo -= W1_F0D_READ_MAXLEN;
+               buf += W1_F0D_READ_MAXLEN;
+               off += W1_F0D_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_F0D_SCRATCH_SIZE bytes and
+ * must be W1_F0D_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_F0D_PAGE_SIZE - (addr & W1_F0D_PAGE_MASK))
+ * @param data The data to write
+ * @return     0=Success -1=failure
+ */
+static int w1_f0d_write(struct w1_slave *sl, int addr, int len, const u8 *data)
+{
+       int tries = W1_F0D_READ_RETRIES;
+       u8 wrbuf[3];
+       u8 rdbuf[W1_F0D_SCRATCH_SIZE];
+       u8 cs;
+
+       if ((addr & 1) || (len != 2)) {
+               dev_err(&sl->dev, "%s: bad addr/len -  addr=%#x len=%d\n",
+                   __func__, addr, len);
+               return -1;
+       }
+
+retry:
+
+       /* Write the data to the scratchpad */
+       if (w1_reset_select_slave(sl))
+               return -1;
+
+       wrbuf[0] = W1_F0D_WRITE_EEPROM;
+       wrbuf[1] = addr & 0xff;
+       wrbuf[2] = 0xff; /* ?? from Example */
+
+       w1_write_block(sl->master, wrbuf, sizeof(wrbuf));
+       w1_write_block(sl->master, data, len);
+
+       w1_read_block(sl->master, rdbuf, sizeof(rdbuf));
+       /* Compare what was read against the data written */
+       if ((rdbuf[0] != data[0]) || (rdbuf[1] != data[1])) {
+
+               if (--tries)
+                       goto retry;
+
+               dev_err(&sl->dev,
+                       "could not write to eeprom, scratchpad compare failed %d times\n",
+                       W1_F0D_READ_RETRIES);
+               pr_info("%s: rdbuf = %#x %#x data = %#x %#x\n",
+                   __func__, rdbuf[0], rdbuf[1], data[0], data[1]);
+
+               return -1;
+       }
+
+       /* Trigger write out to EEPROM */
+       w1_write_8(sl->master, W1_F0D_RELEASE);
+
+       /* Sleep for tprog ms to wait for the write to complete */
+       msleep(W1_F0D_TPROG_MS);
+
+       /* Check CS (Command Status) == 0xAA ? */
+       cs = w1_read_8(sl->master);
+       if (cs != W1_F0D_CS_OK) {
+               dev_err(&sl->dev, "save to eeprom failed = CS=%#x\n", cs);
+               return -1;
+       }
+
+       return 0;
+}
+
+static ssize_t w1_f0d_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;
+       int copy;
+
+       count = w1_f0d_fix_count(off, count, W1_F0D_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_F0D_SCRATCH_SIZE || addr & W1_F0D_SCRATCH_MASK) {
+                       char tmp[W1_F0D_SCRATCH_SIZE];
+
+                       /* read the block and update the parts to be written */
+                       if (w1_f0d_readblock(sl, addr & ~W1_F0D_SCRATCH_MASK,
+                                       W1_F0D_SCRATCH_SIZE, tmp)) {
+                               count = -EIO;
+                               goto out_up;
+                       }
+
+                       /* copy at most to the boundary of the PAGE or len */
+                       copy = W1_F0D_SCRATCH_SIZE -
+                               (addr & W1_F0D_SCRATCH_MASK);
+
+                       if (copy > len)
+                               copy = len;
+
+                       memcpy(&tmp[addr & W1_F0D_SCRATCH_MASK], buf, copy);
+                       if (w1_f0d_write(sl, addr & ~W1_F0D_SCRATCH_MASK,
+                                       W1_F0D_SCRATCH_SIZE, tmp) < 0) {
+                               count = -EIO;
+                               goto out_up;
+                       }
+               } else {
+
+                       copy = W1_F0D_SCRATCH_SIZE;
+                       if (w1_f0d_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_f0d_bin_attr = {
+       .attr = {
+               .name = "eeprom",
+               .mode = S_IRUGO | S_IWUSR,
+       },
+       .size = W1_F0D_EEPROM_SIZE,
+       .read = w1_f0d_read_bin,
+       .write = w1_f0d_write_bin,
+};
+
+static int w1_f0d_add_slave(struct w1_slave *sl)
+{
+       return sysfs_create_bin_file(&sl->dev.kobj, &w1_f0d_bin_attr);
+}
+
+static void w1_f0d_remove_slave(struct w1_slave *sl)
+{
+       sysfs_remove_bin_file(&sl->dev.kobj, &w1_f0d_bin_attr);
+}
+
+static struct w1_family_ops w1_f0d_fops = {
+       .add_slave      = w1_f0d_add_slave,
+       .remove_slave   = w1_f0d_remove_slave,
+};
+
+static struct w1_family w1_family_2d = {
+       .fid = W1_EEPROM_DS2805,
+       .fops = &w1_f0d_fops,
+};
+
+static int __init w1_f0d_init(void)
+{
+       pr_info("%s()\n", __func__);
+       return w1_register_family(&w1_family_2d);
+}
+
+static void __exit w1_f0d_fini(void)
+{
+       pr_info("%s()\n", __func__);
+       w1_unregister_family(&w1_family_2d);
+}
+
+module_init(w1_f0d_init);
+module_exit(w1_f0d_fini);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Andrew Worsley amworsley@gmail.com");
+MODULE_DESCRIPTION("w1 family 0d driver for DS2805, 1kb EEPROM");
index 0f614dfcb09f1c09157816f0d9fa08d72dec0b95..3c76e1ca4b83cc663e49ae28fdb7e4615e8da054 100644 (file)
@@ -729,6 +729,8 @@ int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn)
        atomic_set(&sl->refcnt, 1);
        atomic_inc(&sl->master->refcnt);
        dev->slave_count++;
+       dev_info(&dev->dev, "Attaching one wire slave %02x.%012llx crc %02x\n",
+                 rn->family, (unsigned long long)rn->id, rn->crc);
 
        /* slave modules need to be loaded in a context with unlocked mutex */
        mutex_unlock(&dev->mutex);