[PATCH] ARM: mxs/mx28evk: add flexcan devices

On Wed, Mar 02, 2011 at 07:45:50PM +0800, Shawn Guo wrote:

On Wed, Mar 02, 2011 at 12:11:48PM +0100, Sascha Hauer wrote:

quoted

Hi Shawn,

Hi Sascha,

quoted

On Wed, Mar 02, 2011 at 06:54:44PM +0800, Shawn Guo wrote:

quoted

Signed-off-by: Shawn Guo <redacted>
---
 arch/arm/mach-mxs/Kconfig        |    1 +
 arch/arm/mach-mxs/mach-mx28evk.c |   37 +++++++++++++++++++++++++++++++++++++
 2 files changed, 38 insertions(+), 0 deletions(-)

diff --git a/arch/arm/mach-mxs/Kconfig b/arch/arm/mach-mxs/Kconfig
index 55bf075..9a1f2cb 100644
--- a/arch/arm/mach-mxs/Kconfig
+++ b/arch/arm/mach-mxs/Kconfig

@@ -31,6 +31,7 @@ config MACH_MX28EVK
 	select MXS_HAVE_AMBA_DUART
 	select MXS_HAVE_PLATFORM_AUART
 	select MXS_HAVE_PLATFORM_FEC
+	select MXS_HAVE_PLATFORM_FLEXCAN
 	select MXS_OCOTP
 	default y
 	help

diff --git a/arch/arm/mach-mxs/mach-mx28evk.c b/arch/arm/mach-mxs/mach-mx28evk.c
index 1f0b708..3cefb73 100644
--- a/arch/arm/mach-mxs/mach-mx28evk.c
+++ b/arch/arm/mach-mxs/mach-mx28evk.c

@@ -28,6 +28,7 @@
 #include "devices-mx28.h"
 #include "gpio.h"
 
+#define MX28EVK_FLEXCAN_SWITCH	MXS_GPIO_NR(2, 13)
 #define MX28EVK_FEC_PHY_POWER	MXS_GPIO_NR(2, 15)
 #define MX28EVK_FEC_PHY_RESET	MXS_GPIO_NR(4, 13)
 

@@ -95,6 +96,15 @@ static const iomux_cfg_t mx28evk_pads[] __initconst = {
 	/* phy reset line */
 	MX28_PAD_ENET0_RX_CLK__GPIO_4_13 |
 		(MXS_PAD_4MA | MXS_PAD_3V3 | MXS_PAD_NOPULL),
+
+	/* flexcan0 */
+	MX28_PAD_GPMI_RDY2__CAN0_TX,
+	MX28_PAD_GPMI_RDY3__CAN0_RX,
+	/* flexcan1 */
+	MX28_PAD_GPMI_CE2N__CAN1_TX,
+	MX28_PAD_GPMI_CE3N__CAN1_RX,
+	/* transceiver power control */
+	MX28_PAD_SSP1_CMD__GPIO_2_13,
 };
 
 /* fec */

@@ -178,8 +188,28 @@ error:
 	return -ETIMEDOUT;
 }
 
+/* flexcan */
+static void mx28evk_flexcan_switch(int enable)
+{
+	static int count;
+
+	if (enable) {
+		if (!count++)
+			gpio_set_value(MX28EVK_FLEXCAN_SWITCH, 1);
+	} else {
+		if (!--count)
+			gpio_set_value(MX28EVK_FLEXCAN_SWITCH, 0);
+	}
+}

Why this count variable? It shouldn't hurt to call gpio_set_value
multiple times.

This gpio controls the power of both flexcan0 and flexcan1
transceivers, and we do not want one power-off really shut the power
down if the other is still on.

Ok, I see. You should add a comment making this clear. Or maybe even
better, add a switch function for each controller and do the actual
switching based on "both off" instead of a counter. This even will
work when the flexcan driver has unbalanced switch calls.

Sascha

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