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authorJean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>2012-10-29 14:02:39 +0100
committerSascha Hauer <s.hauer@pengutronix.de>2012-10-29 22:31:18 +0100
commit5099f5e15cca61faeb82beff102dfd5ba3941ee6 (patch)
tree873e3c0fec6fb06e7a8a4167f53353c46b5bba7b /drivers/w1
parent68a961ac5c317b623a7e82ade12e92ec44adbd59 (diff)
downloadbarebox-5099f5e15cca61faeb82beff102dfd5ba3941ee6.tar.gz
1-wire: add ds2433 support
Based on linux implementation. Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Diffstat (limited to 'drivers/w1')
-rw-r--r--drivers/w1/slaves/Kconfig10
-rw-r--r--drivers/w1/slaves/Makefile1
-rw-r--r--drivers/w1/slaves/w1_ds2433.c196
3 files changed, 207 insertions, 0 deletions
diff --git a/drivers/w1/slaves/Kconfig b/drivers/w1/slaves/Kconfig
index 26150a2..946a0b3 100644
--- a/drivers/w1/slaves/Kconfig
+++ b/drivers/w1/slaves/Kconfig
@@ -14,4 +14,14 @@ config W1_SLAVE_DS2431_WRITE
bool "write support"
depends on W1_SLAVE_DS2431
+config W1_SLAVE_DS2433
+ bool "4kb EEPROM family support (DS2433)"
+ help
+ Say Y here if you want to use a 1-wire
+ 4kb EEPROM family device (DS2433).
+
+config W1_SLAVE_DS2433_WRITE
+ bool "write support"
+ depends on W1_SLAVE_DS2433
+
endmenu
diff --git a/drivers/w1/slaves/Makefile b/drivers/w1/slaves/Makefile
index 65804e0..dd7160a 100644
--- a/drivers/w1/slaves/Makefile
+++ b/drivers/w1/slaves/Makefile
@@ -3,3 +3,4 @@
#
obj-$(CONFIG_W1_SLAVE_DS2431) += w1_ds2431.o
+obj-$(CONFIG_W1_SLAVE_DS2433) += w1_ds2433.o
diff --git a/drivers/w1/slaves/w1_ds2433.c b/drivers/w1/slaves/w1_ds2433.c
new file mode 100644
index 0000000..51279fb
--- /dev/null
+++ b/drivers/w1/slaves/w1_ds2433.c
@@ -0,0 +1,196 @@
+/*
+ * w1_ds2433.c - w1 family 23 (DS2433) driver
+ *
+ * Copyright (c) 2005 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 <init.h>
+#include "../w1.h"
+
+#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_F23_TIME 300
+
+#define W1_F23_READ_EEPROM 0xF0
+#define W1_F23_WRITE_SCRATCH 0x0F
+#define W1_F23_READ_SCRATCH 0xAA
+#define W1_F23_COPY_SCRATCH 0x55
+
+#define DRIVERNAME "ds2433"
+
+static int ds2433_count = 0;
+
+/**
+ * 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 ds2433_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 ds2433_cdev_read(struct cdev *cdev, void *buf, size_t count,
+ loff_t off, ulong flags)
+{
+ struct w1_device *dev = cdev->priv;
+ struct w1_bus *bus = dev->bus;
+ u8 wrbuf[3];
+
+ if ((count = ds2433_fix_count(off, count, W1_EEPROM_SIZE)) == 0)
+ return 0;
+
+ /* read directly from the EEPROM */
+ if (w1_reset_select_slave(dev)) {
+ count = -EIO;
+ goto out_up;
+ }
+
+ wrbuf[0] = W1_F23_READ_EEPROM;
+ wrbuf[1] = off & 0xff;
+ wrbuf[2] = off >> 8;
+ w1_write_block(bus, wrbuf, 3);
+ w1_read_block(bus, buf, count);
+
+out_up:
+ return count;
+}
+
+#ifdef CONFIG_W1_SLAVE_DS2433_WRITE
+/**
+ * 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 ds2433_write(struct w1_device *dev, int addr, int len, const u8 *data)
+{
+ struct w1_bus *bus = dev->bus;
+ 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(dev))
+ return -1;
+
+ wrbuf[0] = W1_F23_WRITE_SCRATCH;
+ wrbuf[1] = addr & 0xff;
+ wrbuf[2] = addr >> 8;
+
+ w1_write_block(bus, wrbuf, 3);
+ w1_write_block(bus, data, len);
+
+ /* Read the scratchpad and verify */
+ if (w1_reset_select_slave(dev))
+ return -1;
+
+ w1_write_8(bus, W1_F23_READ_SCRATCH);
+ w1_read_block(bus, 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(dev))
+ return -1;
+
+ wrbuf[0] = W1_F23_COPY_SCRATCH;
+ wrbuf[3] = es;
+ w1_write_block(bus, wrbuf, 4);
+
+ /* Sleep for 5 ms to wait for the write to complete */
+ mdelay(5);
+
+ /* Reset the bus to wake up the EEPROM (this may not be needed) */
+ w1_reset_bus(bus);
+ return 0;
+}
+
+static ssize_t ds2433_cdev_write(struct cdev *cdev, const void *buf, size_t count,
+ loff_t off, ulong flags)
+{
+ struct w1_device *dev = cdev->priv;
+ int addr, len, idx;
+ const u8 *buf8 = buf;
+
+ if ((count = ds2433_fix_count(off, count, W1_EEPROM_SIZE)) == 0)
+ return 0;
+
+ /* 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 (ds2433_write(dev, addr, len, &buf8[idx]) < 0) {
+ count = -EIO;
+ goto out_up;
+ }
+ idx += len;
+ }
+
+out_up:
+ return count;
+}
+#else
+#define ds2433_cdev_write NULL
+#endif
+
+static struct file_operations ds2433_ops = {
+ .read = ds2433_cdev_read,
+ .write = ds2433_cdev_write,
+ .lseek = dev_lseek_default,
+};
+
+static int ds2433_probe(struct w1_device *dev)
+{
+ struct cdev *cdev;
+
+ cdev = xzalloc(sizeof(*cdev));
+ cdev->dev = &dev->dev;
+ cdev->priv = dev;
+ cdev->ops = &ds2433_ops;
+ cdev->size = W1_EEPROM_SIZE;
+ cdev->name = asprintf(DRIVERNAME"%d", ds2433_count++);
+ if (cdev->name == NULL)
+ return -ENOMEM;
+
+ return devfs_create(cdev);
+}
+
+struct w1_driver ds2433_driver = {
+ .drv = {
+ .name = DRIVERNAME,
+ },
+ .probe = ds2433_probe,
+ .fid = 0x23,
+};
+
+static int w1_ds2433_init(void)
+{
+ return w1_driver_register(&ds2433_driver);
+}
+device_initcall(w1_ds2433_init);