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ios for mmc chip select

PATCH Applied Pierre Ossman 2 participants 2 messages Aug 29, 2005 – Sep 3, 2005 MMC, SD and SDIO

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#0 lore raw

PATCH 1/2 ios for mmc chip select

Adds a new ios for setting the chip select pin on MMC cards. Needed on SD controllers which use this pin for other things and therefore cannot have it pulled high at all times.

drivers/mmc/mmc.c +12 -0
Index: linux/drivers/mmc/mmc.c
===================================================================
@@ -457,6 +457,11 @@
 {
 	struct mmc_command cmd;
 
+	host->ios.chip_select = MMC_CS_HIGH;
+	host->ops->set_ios(host, &host->ios);
+
+	mmc_delay(1);
+
 	cmd.opcode = MMC_GO_IDLE_STATE;
 	cmd.arg = 0;
 	cmd.flags = MMC_RSP_NONE;
@@ -464,6 +469,11 @@
 	mmc_wait_for_cmd(host, &cmd, 0);
 
 	mmc_delay(1);
+
+	host->ios.chip_select = MMC_CS_DONTCARE;
+	host->ops->set_ios(host, &host->ios);
+
+	mmc_delay(1);
 }
 
 /*
@@ -475,6 +485,7 @@
 
 	host->ios.vdd = bit;
 	host->ios.bus_mode = MMC_BUSMODE_OPENDRAIN;
+	host->ios.chip_select = MMC_CS_DONTCARE;
 	host->ios.power_mode = MMC_POWER_UP;
 	host->ops->set_ios(host, &host->ios);
 
@@ -492,6 +503,7 @@
 	host->ios.clock = 0;
 	host->ios.vdd = 0;
 	host->ios.bus_mode = MMC_BUSMODE_OPENDRAIN;
+	host->ios.chip_select = MMC_CS_DONTCARE;
 	host->ios.power_mode = MMC_POWER_OFF;
 	host->ops->set_ios(host, &host->ios);
 }
include/linux/mmc/host.h +6 -0
Index: linux/include/linux/mmc/host.h
===================================================================
@@ -46,6 +46,12 @@
 #define MMC_BUSMODE_OPENDRAIN	1
 #define MMC_BUSMODE_PUSHPULL	2
 
+	unsigned char	chip_select;		/* SPI chip select */
+
+#define MMC_CS_DONTCARE		0
+#define MMC_CS_HIGH		1
+#define MMC_CS_LOW		2
+
 	unsigned char	power_mode;		/* power supply mode */
 
 #define MMC_POWER_OFF		0
Applied
#1 lore raw
Quoted 3 lines · Pierre Ossman

Adds a new ios for setting the chip select pin on MMC cards. Needed on SD controllers which use this pin for other things and therefore cannot have it pulled high at all times.

Applied, thanks.

Signature · 3 lines
Russell King
 Linux kernel    2.6 ARM Linux   - http://www.arm.linux.org.uk/
 maintainer of:  2.6 Serial core