imx: ventana: add fdt fixup to enable UHS-I support on selected boards

UHS-I support is available on Ventana boards with micro-SD sockets depending
on the board revision. For backwards compatibility to not break users
who have old bootloaders and newer kernels the device-tree on boards with
microSD disables UHS-I support by default by defining the no-1-8-v property
in the esdhc controller node. For models/revisions that support switchable
1.8V/3.3V I/O which is detectable by the presence of a pull-down on the
SD3_VSELECT pin we remove that property to enable support in the kernel.

Additionally we add SD3_VSELECT to the pinmux for clarity (even though U-Boot
does not currently support UHS-I modes requiring 1.8V I/O).

Signed-off-by: Tim Harvey <tharvey@gateworks.com>

board/gateworks/gw_ventana/common.c

@@ -134,6 +134,8 @@ void setup_ventana_i2c(void)
 static iomux_v3_cfg_t const gw_gpio_pads[] = {
 	/* RS232_EN# */
 	IOMUX_PADS(PAD_SD4_DAT3__GPIO2_IO11 | DIO_PAD_CFG),
+	/* SD3_VSELECT */
+	IOMUX_PADS(PAD_NANDF_CS1__GPIO6_IO14 | DIO_PAD_CFG),
 };
 
 /* prototype */
@@ -766,6 +768,11 @@ void setup_iomux_gpio(int board, struct ventana_board_info *info)
 		gpio_request(gpio_cfg[board].wdis, "wlan_dis");
 		gpio_direction_output(gpio_cfg[board].wdis, 1);
 	}
+
+	/* sense vselect pin to see if we support uhs-i */
+	gpio_request(GP_SD3_VSELECT, "sd3_vselect");
+	gpio_direction_input(GP_SD3_VSELECT);
+	gpio_cfg[board].usd_vsel = !gpio_get_value(GP_SD3_VSELECT);
 }
 
 /* setup GPIO pinmux and default configuration per baseboard and env */

board/gateworks/gw_ventana/common.h

@@ -17,6 +17,7 @@
 #define GP_SD3_CD	IMX_GPIO_NR(7, 0)
 #define GP_RS232_EN	IMX_GPIO_NR(2, 11)
 #define GP_MSATA_SEL	IMX_GPIO_NR(2, 8)
+#define GP_SD3_VSELECT	IMX_GPIO_NR(6, 14)
 
 #define UART_PAD_CTRL  (PAD_CTL_PKE | PAD_CTL_PUE |		\
 	PAD_CTL_PUS_100K_UP | PAD_CTL_SPEED_MED |		\
@@ -77,6 +78,7 @@ struct ventana {
 	int usb_sel;
 	int wdis;
 	int msata_en;
+	bool usd_vsel;
 };
 
 extern struct ventana gpio_cfg[GW_UNKNOWN];

board/gateworks/gw_ventana/gw_ventana.c

@@ -60,8 +60,7 @@ static iomux_v3_cfg_t const usdhc3_pads[] = {
 	IOMUX_PADS(PAD_SD3_DAT1__SD3_DATA1 | MUX_PAD_CTRL(USDHC_PAD_CTRL)),
 	IOMUX_PADS(PAD_SD3_DAT2__SD3_DATA2 | MUX_PAD_CTRL(USDHC_PAD_CTRL)),
 	IOMUX_PADS(PAD_SD3_DAT3__SD3_DATA3 | MUX_PAD_CTRL(USDHC_PAD_CTRL)),
-	/* CD */
-	IOMUX_PADS(PAD_SD3_DAT5__GPIO7_IO00  | MUX_PAD_CTRL(IRQ_PAD_CTRL)),
+	IOMUX_PADS(PAD_SD3_DAT5__GPIO7_IO00  | MUX_PAD_CTRL(USDHC_PAD_CTRL)),
 };
 
 /* ENET */
@@ -792,6 +791,17 @@ static inline void ft_enable_path(void *blob, const char *path)
 	}
 }
 
+/* remove a property of a node if the node is found */
+static inline void ft_delprop_path(void *blob, const char *path,
+				   const char *name)
+{
+	int i = fdt_path_offset(blob, path);
+	if (i) {
+		debug("removing %s/%s\n", path, name);
+		fdt_delprop(blob, i, name);
+	}
+}
+
 /*
  * called prior to booting kernel or by 'fdt boardsetup' command
  *
@@ -895,6 +905,11 @@ int ft_board_setup(void *blob, bd_t *bd)
 				range[1] = cpu_to_fdt32(23);
 			}
 		}
+
+		/* these have broken usd_vsel */
+		if (strstr((const char *)info->model, "SP318-B") ||
+		    strstr((const char *)info->model, "SP331-B"))
+			gpio_cfg[board_type].usd_vsel = 0;
 	}
 
 	/*
@@ -954,6 +969,13 @@ int ft_board_setup(void *blob, bd_t *bd)
 		}
 	}
 
+	/* remove no-1-8-v if UHS-I support is present */
+	if (gpio_cfg[board_type].usd_vsel) {
+		debug("Enabling UHS-I support\n");
+		ft_delprop_path(blob, "/soc/aips-bus@02100000/usdhc@02198000",
+				"no-1-8-v");
+	}
+
 	/*
 	 * Peripheral Config:
 	 *  remove nodes by alias path if EEPROM config tells us the