board: samsung: exynos-mobile: add exynos7870 support and three devices

Add basic support for the Exynos7870 SoC, this includes device tree
match logic using multiple boards, where devices use a stub dtb in
Samsung's QCDT format. S-BOOT, the previous stage bootloader, places its
cmdline arguments there, which has identifying information.

This is added with support for three devices:
 * Samsung Galaxy A2 Core (codename: a2corelte)
 * Samsung Galaxy J6 (codename: j6lte)
 * Samsung Galaxy J7 Prime (codename: on7xelte)

Add their device trees in the defconfig, and also enable the clock and
pin controller drivers.

Signed-off-by: Kaustabh Chakraborty <kauschluss@disroot.org>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>

board/samsung/exynos-mobile/debug-exynos7870.config

@@ -0,0 +1,7 @@
+CONFIG_DEBUG_UART=y
+CONFIG_DEBUG_UART_BASE=0x13820000
+CONFIG_DEBUG_UART_CLOCK=133250000
+CONFIG_DEBUG_UART_S5P=y
+CONFIG_LOG=y
+CONFIG_LOG_CONSOLE=y
+CONFIG_LOG_MAX_LEVEL=8

board/samsung/exynos-mobile/exynos-mobile.c

@@ -13,6 +13,7 @@
 #include <env.h>
 #include <errno.h>
 #include <init.h>
+#include <limits.h>
 #include <linux/sizes.h>
 #include <lmb.h>
 #include <part.h>
@@ -53,6 +54,96 @@ static struct mm_region exynos_mem_map[CONFIG_NR_DRAM_BANKS + 2] = {
 
 struct mm_region *mem_map = exynos_mem_map;
 
+static const u64 exynos7870_common_dram_bank_bases[CONFIG_NR_DRAM_BANKS] = {
+	0x40000000, 0x80000000, 0x100000000,
+};
+
+static const char *exynos_prev_bl_get_bootargs(void)
+{
+	void *prev_bl_fdt_base = (void *)get_prev_bl_fdt_addr();
+	int chosen_node_offset, ret;
+	const struct fdt_property *bootargs_prop;
+
+	ret = fdt_check_header(prev_bl_fdt_base);
+	if (ret < 0) {
+		log_err("%s: FDT is invalid (FDT_ERR %d)\n", __func__, ret);
+		return NULL;
+	}
+
+	ret = fdt_path_offset(prev_bl_fdt_base, "/chosen");
+	chosen_node_offset = ret;
+	if (ret < 0) {
+		log_err("%s: /chosen node not found (FDT_ERR %d)\n", __func__,
+			ret);
+		return NULL;
+	}
+
+	bootargs_prop = fdt_get_property(prev_bl_fdt_base, chosen_node_offset,
+					 "bootargs", &ret);
+	if (!bootargs_prop) {
+		log_err("%s: /chosen/bootargs property not found (FDT_ERR %d)\n",
+			__func__, ret);
+		return NULL;
+	}
+
+	return bootargs_prop->data;
+}
+
+static int exynos7870_fdt_match(struct exynos_board_info *board_info)
+{
+	const char *prev_bl_bootargs;
+	int val, ret;
+
+	prev_bl_bootargs = exynos_prev_bl_get_bootargs();
+	if (!prev_bl_bootargs)
+		return -1;
+
+	/*
+	 * Read the cmdline property which stores the
+	 * bootloader/firmware version. An example value of the option
+	 * can be: "J600GDXU3ARH5". This can be used to verify the model
+	 * of the device.
+	 */
+	ret = cmdline_get_arg(prev_bl_bootargs, "androidboot.bootloader", &val);
+	if (ret < 0) {
+		log_err("%s: unable to find property for bootloader version (%d)\n",
+			__func__, ret);
+		return -1;
+	}
+
+	if (strncmp(prev_bl_bootargs + val, board_info->match_model,
+		    strlen(board_info->match_model)))
+		return -1;
+
+	/*
+	 * Read the cmdline property which stores the hardware revision.
+	 * This is required to allow selecting one of multiple dtbs
+	 * available of a single device, varying in hardware changes in
+	 * different revisions.
+	 */
+	ret = cmdline_get_arg(prev_bl_bootargs, "androidboot.revision", &val);
+	if (ret < 0)
+		ret = cmdline_get_arg(prev_bl_bootargs, "androidboot.hw_rev", &val);
+	if (ret < 0) {
+		log_err("%s: unable to find property for bootloader revision (%d)\n",
+			__func__, ret);
+		return -1;
+	}
+
+	if (strtoul(prev_bl_bootargs + val, NULL, 10) > board_info->match_max_rev)
+		return -1;
+
+	/*
+	 * Read the cmdline property which stores the serial number.
+	 * Store this in the board info struct.
+	 */
+	ret = cmdline_get_arg(prev_bl_bootargs, "androidboot.serialno", &val);
+	if (ret > 0)
+		strlcpy(board_info->serial, prev_bl_bootargs + val, ret);
+
+	return 0;
+}
+
 /*
  * This array is used for matching the models and revisions with the
  * devicetree used by U-Boot. This allows a single U-Boot to work on
@@ -62,6 +153,31 @@ struct mm_region *mem_map = exynos_mem_map;
  * board names.
  */
 static struct exynos_board_info exynos_board_info_match[] = {
+	{
+		/* Samsung Galaxy A2 Core */
+		.name = "a2corelte",
+		.chip = "exynos7870",
+		.dram_bank_bases = exynos7870_common_dram_bank_bases,
+		.match = exynos7870_fdt_match,
+		.match_model = "A260",
+		.match_max_rev = U8_MAX,
+	}, {
+		/* Samsung Galaxy J6 */
+		.name = "j6lte",
+		.chip = "exynos7870",
+		.dram_bank_bases = exynos7870_common_dram_bank_bases,
+		.match = exynos7870_fdt_match,
+		.match_model = "J600",
+		.match_max_rev = U8_MAX,
+	}, {
+		/* Samsung Galaxy J7 Prime */
+		.name = "on7xelte",
+		.chip = "exynos7870",
+		.dram_bank_bases = exynos7870_common_dram_bank_bases,
+		.match = exynos7870_fdt_match,
+		.match_model = "G610",
+		.match_max_rev = U8_MAX,
+	},
 };
 
 static void exynos_parse_dram_banks(const struct exynos_board_info *board_info,

configs/exynos-mobile_defconfig

@@ -7,6 +7,7 @@ CONFIG_SYS_MALLOC_LEN=0x2000000
 CONFIG_SYS_MALLOC_F_LEN=0x16000
 CONFIG_TARGET_EXYNOS_MOBILE=y
 CONFIG_NR_DRAM_BANKS=3
+CONFIG_DEFAULT_DEVICE_TREE="exynos/exynos7870-a2corelte"
 CONFIG_SYS_BOOTM_LEN=0x2000000
 CONFIG_SYS_LOAD_ADDR=0x80000000
 CONFIG_ARMV8_CNTFRQ_BROKEN=y
@@ -24,11 +25,13 @@ CONFIG_CMD_POWEROFF=y
 CONFIG_CMD_FS_GENERIC=y
 CONFIG_EFI_PARTITION=y
 CONFIG_OF_UPSTREAM=y
+CONFIG_OF_LIST="exynos/exynos7870-a2corelte exynos/exynos7870-j6lte exynos/exynos7870-on7xelte"
 CONFIG_MULTI_DTB_FIT=y
 CONFIG_BUTTON=y
 CONFIG_BUTTON_REMAP_PHONE_KEYS=y
 CONFIG_CLK=y
 CONFIG_CLK_CCF=y
+CONFIG_CLK_EXYNOS7870=y
 CONFIG_USB_FUNCTION_FASTBOOT=y
 CONFIG_FASTBOOT_BUF_ADDR=0xdead0000
 CONFIG_FASTBOOT_FLASH=y
@@ -44,6 +47,7 @@ CONFIG_MMC_DW=y
 CONFIG_PHY=y
 CONFIG_PHY_EXYNOS_USBDRD=y
 CONFIG_PINCTRL=y
+CONFIG_PINCTRL_EXYNOS78x0=y
 CONFIG_DM_PMIC=y
 CONFIG_PMIC_S2MPS11=y
 CONFIG_DM_REGULATOR=y