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authorAlexey Brodkin <Alexey.Brodkin@synopsys.com>2013-12-16 15:30:35 +0400
committerHeiko Schocher <hs@denx.de>2014-01-13 08:18:13 +0100
commit32d041e218c6a22e92d91629902fd03a90934b6a (patch)
tree6688c226e5855ace49eda156910676a132e816dc
parent7cc1b02f8f73fc0b5e1531a1e16b1c00819d5222 (diff)
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drivers/designware_i2c - add suppor of CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW
Since we agreed on legacy implementation of "eeprom_{read|write}" (http://patchwork.ozlabs.org/patch/295825/) I had to fix/make it work again DesignWare I2C driver for cases when 1 EEPROM IC fake I2C with anumber of "built-in" ICs with different chip addresses. Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com> Cc: Tom Rini <trini@ti.com> cc: Armando Visconti <armando.visconti@st.com> Cc: Stefan Roese <sr@denx.de> Cc: Albert ARIBAUD <albert.u.boot@aribaud.net> Cc: Heiko Schocher <hs@denx.de> Cc: Vipin KUMAR <vipin.kumar@st.com> Cc: Tom Rix <Tom.Rix@windriver.com> Cc: Mischa Jonker <mjonker@synopsys.com> Cc: Kuo-Jung Su <dantesu@faraday-tech.com>
-rw-r--r--drivers/i2c/designware_i2c.c38
1 files changed, 38 insertions, 0 deletions
diff --git a/drivers/i2c/designware_i2c.c b/drivers/i2c/designware_i2c.c
index cb2ac04..9ed9295 100644
--- a/drivers/i2c/designware_i2c.c
+++ b/drivers/i2c/designware_i2c.c
@@ -266,6 +266,25 @@ int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len)
{
unsigned long start_time_rx;
+#ifdef CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW
+ /*
+ * EEPROM chips that implement "address overflow" are ones
+ * like Catalyst 24WC04/08/16 which has 9/10/11 bits of
+ * address and the extra bits end up in the "chip address"
+ * bit slots. This makes a 24WC08 (1Kbyte) chip look like
+ * four 256 byte chips.
+ *
+ * Note that we consider the length of the address field to
+ * still be one byte because the extra address bits are
+ * hidden in the chip address.
+ */
+ chip |= ((addr >> (alen * 8)) & CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW);
+ addr &= ~(CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW << (alen * 8));
+
+ debug("%s: fix addr_overflow: chip %02x addr %02x\n", __func__, chip,
+ addr);
+#endif
+
if (check_params(addr, alen, buffer, len))
return 1;
@@ -307,6 +326,25 @@ int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len)
int nb = len;
unsigned long start_time_tx;
+#ifdef CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW
+ /*
+ * EEPROM chips that implement "address overflow" are ones
+ * like Catalyst 24WC04/08/16 which has 9/10/11 bits of
+ * address and the extra bits end up in the "chip address"
+ * bit slots. This makes a 24WC08 (1Kbyte) chip look like
+ * four 256 byte chips.
+ *
+ * Note that we consider the length of the address field to
+ * still be one byte because the extra address bits are
+ * hidden in the chip address.
+ */
+ chip |= ((addr >> (alen * 8)) & CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW);
+ addr &= ~(CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW << (alen * 8));
+
+ debug("%s: fix addr_overflow: chip %02x addr %02x\n", __func__, chip,
+ addr);
+#endif
+
if (check_params(addr, alen, buffer, len))
return 1;