imx8mm-cl-iot-gate: Add SPL EEPROM support

imx8mm-cl-iot-gate supports multiple DDR sizes and models.

The DDR type can be retrieved from the EEPROM, so add SPL code
that can be used to get the DDR information.

Based on the original code from Compulab's U-Boot.

Signed-off-by: Fabio Estevam <festevam@denx.de>
diff --git a/board/compulab/imx8mm-cl-iot-gate/eeprom_spl.c b/board/compulab/imx8mm-cl-iot-gate/eeprom_spl.c
new file mode 100644
index 0000000..ee6d2bb
--- /dev/null
+++ b/board/compulab/imx8mm-cl-iot-gate/eeprom_spl.c
@@ -0,0 +1,130 @@
+// SPDX-License-Identifier: GPL-2.0+
+/* (C) Copyright 2019 CompuLab, Ltd. <www.compulab.co.il> */
+
+#include <common.h>
+#include <i2c.h>
+#include <linux/kernel.h>
+#include <asm/arch/imx8mq_pins.h>
+#include <asm/mach-imx/gpio.h>
+#include <asm-generic/gpio.h>
+#include <asm/setup.h>
+#include <linux/delay.h>
+
+#ifdef CONFIG_SPL_BUILD
+
+#define CONFIG_SYS_I2C_EEPROM_ADDR_P1	0x51
+#define CONFIG_SYS_I2C_EEPROM_ADDR_LEN	1
+
+static iomux_v3_cfg_t const eeprom_pads[] = {
+	IMX8MQ_PAD_GPIO1_IO13__GPIO1_IO13 | MUX_PAD_CTRL(NO_PAD_CTRL),
+};
+
+#define EEPROM_WP_GPIO IMX_GPIO_NR(1, 13)
+
+static void cl_eeprom_we(int enable)
+{
+	static int done;
+
+	if (done) {
+		gpio_direction_output(EEPROM_WP_GPIO, enable);
+		return;
+	}
+
+	imx_iomux_v3_setup_multiple_pads(eeprom_pads, ARRAY_SIZE(eeprom_pads));
+	gpio_request(EEPROM_WP_GPIO, "eeprom_wp");
+	gpio_direction_output(EEPROM_WP_GPIO, enable);
+	done = 1;
+}
+
+static int cl_eeprom_read(uint offset, uchar *buf, int len)
+{
+	struct udevice *dev;
+	int ret;
+
+	ret = i2c_get_chip_for_busnum(1, CONFIG_SYS_I2C_EEPROM_ADDR_P1,
+				      CONFIG_SYS_I2C_EEPROM_ADDR_LEN, &dev);
+	if (ret) {
+		printf("%s: Cannot find EEPROM: %d\n", __func__, ret);
+		return ret;
+	}
+
+	return dm_i2c_read(dev, offset, buf, len);
+}
+
+static int cl_eeprom_write(uint offset, uchar *buf, int len)
+{
+	struct udevice *dev;
+	int ret;
+
+	cl_eeprom_we(1);
+
+	ret = i2c_get_chip_for_busnum(1, CONFIG_SYS_I2C_EEPROM_ADDR_P1,
+				      CONFIG_SYS_I2C_EEPROM_ADDR_LEN, &dev);
+	if (ret) {
+		printf("%s: Cannot find EEPROM: %d\n", __func__, ret);
+		return ret;
+	}
+
+	return dm_i2c_write(dev, offset, buf, len);
+}
+
+/* Reserved for fututre use area */
+#define BOARD_DDRINFO_OFFSET 0x40
+#define BOARD_DDR_SIZE 4
+static u32 board_ddrinfo = 0xdeadbeef;
+
+#define BOARD_DDRSUBIND_OFFSET 0x44
+#define BOARD_DDRSUBIND_SIZE 1
+static u8 board_ddrsubind = 0xff;
+
+#define BOARD_OSIZE_OFFSET 0x80
+#define BOARD_OSIZE_SIZE 4
+static u32 board_osize = 0xdeadbeef;
+
+#define BOARD_DDRINFO_VALID(A) ((A) != 0xdeadbeef)
+
+u32 cl_eeprom_get_ddrinfo(void)
+{
+	if (!BOARD_DDRINFO_VALID(board_ddrinfo)) {
+		if (cl_eeprom_read(BOARD_DDRINFO_OFFSET, (uchar *)&board_ddrinfo, BOARD_DDR_SIZE))
+			return 0;
+	}
+	return board_ddrinfo;
+};
+
+u32 cl_eeprom_set_ddrinfo(u32 ddrinfo)
+{
+	if (cl_eeprom_write(BOARD_DDRINFO_OFFSET, (uchar *)&ddrinfo, BOARD_DDR_SIZE))
+		return 0;
+
+	board_ddrinfo = ddrinfo;
+
+	return board_ddrinfo;
+};
+
+u8 cl_eeprom_get_subind(void)
+{
+	if (cl_eeprom_read(BOARD_DDRSUBIND_OFFSET, (uchar *)&board_ddrsubind, BOARD_DDRSUBIND_SIZE))
+		return 0xff;
+
+	return board_ddrsubind;
+};
+
+u8 cl_eeprom_set_subind(u8 ddrsubind)
+{
+	if (cl_eeprom_write(BOARD_DDRSUBIND_OFFSET, (uchar *)&ddrsubind, BOARD_DDRSUBIND_SIZE))
+		return 0xff;
+	board_ddrsubind = ddrsubind;
+
+	return board_ddrsubind;
+};
+
+/* override-size ifaces */
+u32 cl_eeprom_get_osize(void)
+{
+	if (cl_eeprom_read(BOARD_OSIZE_OFFSET, (uchar *)&board_osize, BOARD_OSIZE_SIZE))
+		return 0;
+
+	return board_osize;
+};
+#endif