arm: dra7: Allow NAND to be enabled on DRA71x EVM.

If SW 8 pins 0 and 1 indicate that NAND should be enabled then
the pins pinmux must be reconfigured for NAND mode.

Therefore, enable NAND by reconfiguring the pinmux.

Signed-off-by: Franklin S Cooper Jr <fcooper@ti.com>
Signed-off-by: Faiz Abbas <faiz_abbas@ti.com>

diff --git a/board/ti/dra7xx/evm.c b/board/ti/dra7xx/evm.c
index 060c471..179adc2 100644 (file)
--- a/board/ti/dra7xx/evm.c
+++ b/board/ti/dra7xx/evm.c
@@ -27,6 +27,7 @@
 #include <environment.h>
 #include <dwc3-uboot.h>
 #include <dwc3-omap-uboot.h>
+#include <i2c.h>
 #include <ti-usb-phy-uboot.h>
 #include <miiphy.h>
 
@@ -55,6 +56,10 @@ DECLARE_GLOBAL_DATA_PTR;
 
 #define SYSINFO_BOARD_NAME_MAX_LEN     37
 
+/* I2C I/O Expander */
+#define NAND_PCF8575_ADDR      0x21
+#define NAND_PCF8575_I2C_BUS_NUM       0
+
 const struct omap_sysinfo sysinfo = {
        "Board: UNKNOWN(DRA7 EVM) REV UNKNOWN\n"
 };
@@ -777,6 +782,44 @@ void set_muxconf_regs(void)
                     early_padconf, ARRAY_SIZE(early_padconf));
 }
 
+#if defined(CONFIG_NAND)
+static int nand_sw_detect(void)
+{
+       int rc;
+       uchar data[2];
+       struct udevice *dev;
+
+       rc = i2c_get_chip_for_busnum(NAND_PCF8575_I2C_BUS_NUM,
+                                    NAND_PCF8575_ADDR, 0, &dev);
+       if (rc)
+               return -1;
+
+       rc = dm_i2c_read(dev, 0, (uint8_t *)&data, sizeof(data));
+       if (rc)
+               return -1;
+
+       /* We are only interested in P10 and P11 on PCF8575 which is equal to
+        * bits 8 and 9.
+        */
+       data[1] = data[1] & 0x3;
+
+       /* Ensure only P11 is set and P10 is cleared. This ensures only
+        * NAND (P10) is configured and not NOR (P11) which are both low
+        * true signals. NAND and NOR settings should not be enabled at
+        * the same time.
+        */
+       if (data[1] == 0x2)
+               return 0;
+
+       return -1;
+}
+#else
+int nand_sw_detect(void)
+{
+       return -1;
+}
+#endif
+
 #ifdef CONFIG_IODELAY_RECALIBRATION
 void recalibrate_iodelay(void)
 {
@@ -796,6 +839,19 @@ void recalibrate_iodelay(void)
                        npads = ARRAY_SIZE(dra71x_core_padconf_array);
                        iodelay = dra71_iodelay_cfg_array;
                        niodelays = ARRAY_SIZE(dra71_iodelay_cfg_array);
+                       /* If SW8 on the EVM is set to enable NAND then
+                        * overwrite the pins used by VOUT3 with NAND.
+                        */
+                       if (!nand_sw_detect()) {
+                               delta_pads = dra71x_nand_padconf_array;
+                               delta_npads =
+                                       ARRAY_SIZE(dra71x_nand_padconf_array);
+                       } else {
+                               delta_pads = dra71x_vout3_padconf_array;
+                               delta_npads =
+                                       ARRAY_SIZE(dra71x_vout3_padconf_array);
+                       }
+
                } else if (board_is_dra72x_revc_or_later()) {
                        delta_pads = dra72x_rgmii_padconf_array_revc;
                        delta_npads =