[RFC,5/7] eeprom: at24: add regmap-based read functions

Message ID 50dc4441-3975-bd30-3514-54fe106a0040@gmail.com
State New
Headers show

Commit Message

Heiner Kallweit Aug. 17, 2017, 5:59 a.m.
Add regmap-based read functions.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
---
 drivers/misc/eeprom/at24.c | 58 +++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 57 insertions(+), 1 deletion(-)

Patch

diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c
index 6c5e5538..55b35007 100644
--- a/drivers/misc/eeprom/at24.c
+++ b/drivers/misc/eeprom/at24.c
@@ -250,6 +250,59 @@  static ssize_t at24_eeprom_read_smbus(struct at24_data *at24, char *buf,
 	return -ETIMEDOUT;
 }
 
+static ssize_t at24_regmap_read(struct at24_data *at24, char *buf,
+				unsigned int offset, size_t count)
+{
+	unsigned long timeout, read_time;
+	struct regmap *regmap;
+
+	regmap = at24_translate_offset(at24, &offset)->regmap;
+
+	if (count > io_limit)
+		count = io_limit;
+
+	if (at24->chip.flags & AT24_FLAG_MAC)
+		offset += 0x90;
+
+	loop_until_timeout(timeout, read_time)
+		if (!regmap_bulk_read(regmap, offset, buf, count))
+			return count;
+
+	return -ETIMEDOUT;
+}
+
+static ssize_t at24_regmap_read_serial(struct at24_data *at24, char *buf,
+				       unsigned int offset, size_t count)
+{
+	unsigned long timeout, read_time;
+	struct regmap *regmap;
+
+	regmap = at24_translate_offset(at24, &offset)->regmap;
+
+	if (count > io_limit)
+		count = io_limit;
+
+	if (at24->chip.flags & AT24_FLAG_ADDR16)
+		/*
+		 * For 16 bit address pointers, the word address must contain
+		 * a '10' sequence in bits 11 and 10 regardless of the
+		 * intended position of the address pointer.
+		 */
+		offset |= BIT(11);
+	else
+		/*
+		 * Otherwise the word address must begin with a '10' sequence,
+		 * regardless of the intended address.
+		 */
+		offset |= BIT(7);
+
+	loop_until_timeout(timeout, read_time)
+		if (!regmap_bulk_read(regmap, offset, buf, count))
+			return count;
+
+	return -ETIMEDOUT;
+}
+
 static ssize_t at24_eeprom_read_i2c(struct at24_data *at24, char *buf,
 				    unsigned int offset, size_t count)
 {
@@ -442,7 +495,10 @@  static int at24_read(void *priv, unsigned int off, void *val, size_t count)
 	while (count) {
 		int	status;
 
-		status = at24->read_func(at24, buf, off, count);
+		if (at24->chip.flags & AT24_FLAG_SERIAL)
+			status = at24_regmap_read_serial(at24, buf, off, count);
+		else
+			status = at24_regmap_read(at24, buf, off, count);
 		if (status < 0) {
 			mutex_unlock(&at24->lock);
 			return status;