efikamx: read board id

read board id value from the GPIO3_16/17/11
Signed-off-by: Arnaud Patard <arnaud.patard@rtp-net.org>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

arch/arm/mach-mx5/board-mx51_efikamx.c

@@ -39,12 +39,25 @@
 
 #define	MX51_USB_PLL_DIV_24_MHZ	0x01
 
+#define EFIKAMX_PCBID0		(2*32 + 16)
+#define EFIKAMX_PCBID1		(2*32 + 17)
+#define EFIKAMX_PCBID2		(2*32 + 11)
+
+/* the pci ids pin have pull up. they're driven low according to board id */
+#define MX51_PAD_PCBID0	IOMUX_PAD(0x518, 0x130, 3, 0x0,   0, PAD_CTL_PUS_100K_UP)
+#define MX51_PAD_PCBID1	IOMUX_PAD(0x51C, 0x134, 3, 0x0,   0, PAD_CTL_PUS_100K_UP)
+#define MX51_PAD_PCBID2	IOMUX_PAD(0x504, 0x128, 3, 0x0,   0, PAD_CTL_PUS_100K_UP)
+
 static iomux_v3_cfg_t mx51efikamx_pads[] = {
 	/* UART1 */
 	MX51_PAD_UART1_RXD__UART1_RXD,
 	MX51_PAD_UART1_TXD__UART1_TXD,
 	MX51_PAD_UART1_RTS__UART1_RTS,
 	MX51_PAD_UART1_CTS__UART1_CTS,
+	/* board id */
+	MX51_PAD_PCBID0,
+	MX51_PAD_PCBID1,
+	MX51_PAD_PCBID2,
 };
 
 /* Serial ports */
@@ -92,10 +105,62 @@ static struct mxc_usbh_platform_data dr_utmi_config = {
 	.flags  = MXC_EHCI_INTERNAL_PHY,
 };
 
+/*   PCBID2  PCBID1 PCBID0  STATE
+	1       1      1    ER1:rev1.1
+	1       1      0    ER2:rev1.2
+	1       0      1    ER3:rev1.3
+	1       0      0    ER4:rev1.4
+*/
+static void __init mx51_efikamx_board_id(void)
+{
+	int id;
+
+	/* things are taking time to settle */
+	msleep(150);
+
+	gpio_request(EFIKAMX_PCBID0, "pcbid0");
+	gpio_direction_input(EFIKAMX_PCBID0);
+	gpio_request(EFIKAMX_PCBID1, "pcbid1");
+	gpio_direction_input(EFIKAMX_PCBID1);
+	gpio_request(EFIKAMX_PCBID2, "pcbid2");
+	gpio_direction_input(EFIKAMX_PCBID2);
+
+	id = gpio_get_value(EFIKAMX_PCBID0);
+	id |= gpio_get_value(EFIKAMX_PCBID1) << 1;
+	id |= gpio_get_value(EFIKAMX_PCBID2) << 2;
+
+	switch (id) {
+	case 7:
+		system_rev = 0x11;
+		break;
+	case 6:
+		system_rev = 0x12;
+		break;
+	case 5:
+		system_rev = 0x13;
+		break;
+	case 4:
+		system_rev = 0x14;
+		break;
+	default:
+		system_rev = 0x10;
+		break;
+	}
+
+	if ((system_rev == 0x10)
+		|| (system_rev == 0x12)
+		|| (system_rev == 0x14)) {
+		printk(KERN_WARNING
+			"EfikaMX: Unsupported board revision 1.%u!\n",
+			system_rev & 0xf);
+	}
+}
+
 static void __init mxc_board_init(void)
 {
 	mxc_iomux_v3_setup_multiple_pads(mx51efikamx_pads,
 					ARRAY_SIZE(mx51efikamx_pads));
+	mx51_efikamx_board_id();
 	mxc_register_device(&mxc_usbdr_host_device, &dr_utmi_config);
 	mxc_init_imx_uart();
 }