[PATCH 2/2] board: apalis-imx8: add new 8gb product variant

[Philippe Schenker <dev@pschenker.ch>]

From: Philippe Schenker <philippe.schenker@toradex.com>

Add the new Apalis iMX8 product variant

0067: Apalis iMX8 QuadMax 8GB Wi-Fi / BT IT

the only difference to the product

0037 Apalis iMX8 QuadMax 4GB Wi-Fi / BT IT

is the 8gb of RAM. Toradex strategy to choose the correct RAM timing in
SCFW is by fuses in the user area telling which RAM timing to load.

This commit makes use of this information to set the correct size of
the RAM and therefore distinguish between the new 0067 and 0037 product

Signed-off-by: Philippe Schenker <philippe.schenker@toradex.com>
Reviewed-by: Francesco Dolcini <francesco.dolcini@toradex.com>

---

 board/toradex/apalis-imx8/apalis-imx8.c | 81 +++++++++++++++++++++++--
 1 file changed, 77 insertions(+), 4 deletions(-)

diff --git a/board/toradex/apalis-imx8/apalis-imx8.c b/board/toradex/apalis-imx8/apalis-imx8.c
index 04877fcd94..408198843f 100644
--- a/board/toradex/apalis-imx8/apalis-imx8.c
+++ b/board/toradex/apalis-imx8/apalis-imx8.c
@@ -18,6 +18,7 @@
 #include <env.h>
 #include <errno.h>
 #include <linux/libfdt.h>
+#include <linux/bitops.h>
 
 #include "../common/tdx-cfg-block.h"
 
@@ -28,22 +29,75 @@ DECLARE_GLOBAL_DATA_PTR;
 			 (SC_PAD_28FDSOI_DSE_DV_HIGH << PADRING_DSE_SHIFT) | \
 			 (SC_PAD_28FDSOI_PS_PU << PADRING_PULL_SHIFT))
 
+#define TDX_USER_FUSE_BLOCK1_A	276
+#define TDX_USER_FUSE_BLOCK1_B	277
+#define TDX_USER_FUSE_BLOCK2_A	278
+#define TDX_USER_FUSE_BLOCK2_B	279
+
 static iomux_cfg_t uart1_pads[] = {
 	SC_P_UART1_RX | MUX_PAD_CTRL(UART_PAD_CTRL),
 	SC_P_UART1_TX | MUX_PAD_CTRL(UART_PAD_CTRL),
 };
 
+struct tdx_user_fuses {
+	u16 pid4;
+	u16 vers;
+	u8 ramid;
+};
+
 static void setup_iomux_uart(void)
 {
 	imx8_iomux_setup_multiple_pads(uart1_pads, ARRAY_SIZE(uart1_pads));
 }
 
+static uint32_t do_get_tdx_user_fuse(int a, int b)
+{
+	sc_err_t sciErr;
+	u32 val_a = 0;
+	u32 val_b = 0;
+
+	sciErr = sc_misc_otp_fuse_read(-1, a, &val_a);
+	if (sciErr != SC_ERR_NONE) {
+		printf("Error reading out user fuse %d\n", a);
+		return 0;
+	}
+
+	sciErr = sc_misc_otp_fuse_read(-1, b, &val_b);
+	if (sciErr != SC_ERR_NONE) {
+		printf("Error reading out user fuse %d\n", b);
+		return 0;
+	}
+
+	return ((val_a & 0xffff) << 16) | (val_b & 0xffff);
+}
+
+static void get_tdx_user_fuse(struct tdx_user_fuses *tdxuserfuse)
+{
+	u32 fuse_block;
+
+	fuse_block = do_get_tdx_user_fuse(TDX_USER_FUSE_BLOCK2_A,
+					  TDX_USER_FUSE_BLOCK2_B);
+
+	/*
+	 * Fuse block 2 acts as a backup area, if this reads 0 we want to
+	 * use fuse block 1
+	 */
+	if (fuse_block == 0)
+		fuse_block = do_get_tdx_user_fuse(TDX_USER_FUSE_BLOCK1_A,
+						  TDX_USER_FUSE_BLOCK1_B);
+
+	tdxuserfuse->pid4 = (fuse_block >> 18) & GENMASK(13, 0);
+	tdxuserfuse->vers = (fuse_block >> 4) & GENMASK(13, 0);
+	tdxuserfuse->ramid = fuse_block & GENMASK(3, 0);
+}
+
 void board_mem_get_layout(u64 *phys_sdram_1_start,
 			  u64 *phys_sdram_1_size,
 			  u64 *phys_sdram_2_start,
 			  u64 *phys_sdram_2_size)
 {
 	u32 is_quadplus = 0, val = 0;
+	struct tdx_user_fuses tdxramfuses;
 	sc_err_t scierr = sc_misc_otp_fuse_read(-1, 6, &val);
 
 	if (scierr == SC_ERR_NONE) {
@@ -51,14 +105,33 @@ void board_mem_get_layout(u64 *phys_sdram_1_start,
 		is_quadplus = ((val >> 4) & 0x3) != 0x0;
 	}
 
+	get_tdx_user_fuse(&tdxramfuses);
+
 	*phys_sdram_1_start = PHYS_SDRAM_1;
 	*phys_sdram_1_size = PHYS_SDRAM_1_SIZE;
 	*phys_sdram_2_start = PHYS_SDRAM_2;
-	if (is_quadplus)
-		/* Our QP based SKUs only have 2 GB RAM (PHYS_SDRAM_1_SIZE) */
+
+	switch (tdxramfuses.ramid) {
+	case 1:
+		*phys_sdram_2_size = SZ_2G;
+		break;
+	case 2:
 		*phys_sdram_2_size = 0x0UL;
-	else
-		*phys_sdram_2_size = PHYS_SDRAM_2_SIZE;
+		break;
+	case 3:
+		*phys_sdram_2_size = SZ_2G;
+		break;
+	case 4:
+		*phys_sdram_2_size = SZ_4G + SZ_2G;
+		break;
+	default:
+		if (is_quadplus)
+			/* Our QP based SKUs only have 2 GB RAM (PHYS_SDRAM_1_SIZE) */
+			*phys_sdram_2_size = 0x0UL;
+		else
+			*phys_sdram_2_size = PHYS_SDRAM_2_SIZE;
+		break;
+	}
 }
 
 int board_early_init_f(void)
-- 
2.35.1