[PATCH 2/5] eeprom_93cx6: Add write support
From: Stephen Boyd
Date: Mon Nov 21 2011 - 13:58:08 EST
From: Ben Dooks <ben@xxxxxxxxxxxx>
Add support for writing data to EEPROM.
Signed-off-by: Ben Dooks <ben@xxxxxxxxxxxx>
Cc: Wolfram Sang <w.sang@xxxxxxxxxxxxxx>
Cc: Jean Delvare <khali@xxxxxxxxxxxx>
Cc: Linux Kernel <linux-kernel@xxxxxxxxxxxxxxx>
Signed-off-by: Stephen Boyd <sboyd@xxxxxxxxxxxxxx>
---
drivers/misc/eeprom/eeprom_93cx6.c | 85 ++++++++++++++++++++++++++++++++++++
include/linux/eeprom_93cx6.h | 6 +++
2 files changed, 91 insertions(+), 0 deletions(-)
diff --git a/drivers/misc/eeprom/eeprom_93cx6.c b/drivers/misc/eeprom/eeprom_93cx6.c
index a6037af..0ff4b02 100644
--- a/drivers/misc/eeprom/eeprom_93cx6.c
+++ b/drivers/misc/eeprom/eeprom_93cx6.c
@@ -234,3 +234,88 @@ void eeprom_93cx6_multiread(struct eeprom_93cx6 *eeprom, const u8 word,
}
EXPORT_SYMBOL_GPL(eeprom_93cx6_multiread);
+/**
+ * eeprom_93cx6_wren - set the write enable state
+ * @eeprom: Pointer to eeprom structure
+ * @enable: true to enable writes, otherwise disable writes
+ *
+ * Set the EEPROM write enable state to either allow or deny
+ * writes depending on the @enable value.
+ */
+void eeprom_93cx6_wren(struct eeprom_93cx6 *eeprom, bool enable)
+{
+ u16 command;
+
+ /* start the command */
+ eeprom_93cx6_startup(eeprom);
+
+ /* create command to enable/disable */
+
+ command = enable ? PCI_EEPROM_EWEN_OPCODE : PCI_EEPROM_EWDS_OPCODE;
+ command <<= (eeprom->width - 2);
+
+ eeprom_93cx6_write_bits(eeprom, command,
+ PCI_EEPROM_WIDTH_OPCODE + eeprom->width);
+
+ eeprom_93cx6_cleanup(eeprom);
+}
+EXPORT_SYMBOL_GPL(eeprom_93cx6_wren);
+
+/**
+ * eeprom_93cx6_write - write data to the EEPROM
+ * @eeprom: Pointer to eeprom structure
+ * @addr: Address to write data to.
+ * @data: The data to write to address @addr.
+ *
+ * Write the @data to the specified @addr in the EEPROM and
+ * waiting for the device to finish writing.
+ *
+ * Note, since we do not expect large number of write operations
+ * we delay in between parts of the operation to avoid using excessive
+ * amounts of CPU time busy waiting.
+ */
+void eeprom_93cx6_write(struct eeprom_93cx6 *eeprom, u8 addr, u16 data)
+{
+ int timeout = 100;
+ u16 command;
+
+ /* start the command */
+ eeprom_93cx6_startup(eeprom);
+
+ command = PCI_EEPROM_WRITE_OPCODE << eeprom->width;
+ command |= addr;
+
+ /* send write command */
+ eeprom_93cx6_write_bits(eeprom, command,
+ PCI_EEPROM_WIDTH_OPCODE + eeprom->width);
+
+ /* send data */
+ eeprom_93cx6_write_bits(eeprom, data, 16);
+
+ /* get ready to check for busy */
+ eeprom->drive_data = 0;
+ eeprom->reg_chip_select = 1;
+ eeprom->register_write(eeprom);
+
+ /* wait at-least 250ns to get DO to be the busy signal */
+ usleep_range(1000, 2000);
+
+ /* wait for DO to go high to signify finish */
+
+ while (true) {
+ eeprom->register_read(eeprom);
+
+ if (eeprom->reg_data_out)
+ break;
+
+ usleep_range(1000, 2000);
+
+ if (--timeout <= 0) {
+ printk(KERN_ERR "%s: timeout\n", __func__);
+ break;
+ }
+ }
+
+ eeprom_93cx6_cleanup(eeprom);
+}
+EXPORT_SYMBOL_GPL(eeprom_93cx6_write);
diff --git a/include/linux/eeprom_93cx6.h b/include/linux/eeprom_93cx6.h
index e04546e..e50f98b 100644
--- a/include/linux/eeprom_93cx6.h
+++ b/include/linux/eeprom_93cx6.h
@@ -33,6 +33,7 @@
#define PCI_EEPROM_WIDTH_93C86 8
#define PCI_EEPROM_WIDTH_OPCODE 3
#define PCI_EEPROM_WRITE_OPCODE 0x05
+#define PCI_EEPROM_ERASE_OPCODE 0x07
#define PCI_EEPROM_READ_OPCODE 0x06
#define PCI_EEPROM_EWDS_OPCODE 0x10
#define PCI_EEPROM_EWEN_OPCODE 0x13
@@ -74,3 +75,8 @@ extern void eeprom_93cx6_read(struct eeprom_93cx6 *eeprom,
const u8 word, u16 *data);
extern void eeprom_93cx6_multiread(struct eeprom_93cx6 *eeprom,
const u8 word, __le16 *data, const u16 words);
+
+extern void eeprom_93cx6_wren(struct eeprom_93cx6 *eeprom, bool enable);
+
+extern void eeprom_93cx6_write(struct eeprom_93cx6 *eeprom,
+ u8 addr, u16 data);
--
Sent by an employee of the Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.
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