[PATCH 02/12] arm: xea: Add support for reading SoM (CPU) and base board HW revision

Lukasz Majewski
2024-03-22T11:43:56Z

The XEA board now has several HW revisions for both SoM and base boards.
This patch provides support for reading those revision ID values in SPL
(u-boot.sb) and then pass this information to u-boot proper, as the
maximal SPL size (~55KiB) is not allowing for having FIT support in it.

It was necessary to handle reading GPIOs values solely in u-boot proper
as one configuration (i.e. 'single binary' - imx28_xea_sb_defconfig)
is not using SPL framework.

Signed-off-by: Lukasz Majewski <lukma@denx.de>
---

board/liebherr/xea/spl_xea.c | 11 +++++++++++
board/liebherr/xea/xea.c | 29 +++++++++++++++++++++++++++++
2 files changed, 40 insertions(+)

diff --git a/board/liebherr/xea/spl_xea.c b/board/liebherr/xea/spl_xea.c
index 551ed6fbae..71194db235 100644
--- a/board/liebherr/xea/spl_xea.c
+++ b/board/liebherr/xea/spl_xea.c
@@ -230,6 +230,17 @@ const iomux_cfg_t iomux_setup[] = {
/* TIVA boot control */
MX28_PAD_GPMI_RDY3__GPIO_0_23 | MUX_CONFIG_BOOT, /* TIVA0 */
MX28_PAD_GPMI_WRN__GPIO_0_25 | MUX_CONFIG_BOOT, /* TIVA1 */
+
+ /* HW revision ID Base Board */
+ MX28_PAD_LCD_D12__GPIO_1_12,
+ MX28_PAD_LCD_D13__GPIO_1_13,
+ MX28_PAD_LCD_D14__GPIO_1_14,
+
+ /* HW revision ID (SoM) */
+ MX28_PAD_LCD_D15__GPIO_1_15,
+ MX28_PAD_LCD_D16__GPIO_1_16,
+ MX28_PAD_LCD_D17__GPIO_1_17,
+ MX28_PAD_LCD_D18__GPIO_1_18,
};

u32 mxs_dram_vals[] = {
diff --git a/board/liebherr/xea/xea.c b/board/liebherr/xea/xea.c
index c8ac526cb4..d9cf27c81b 100644
--- a/board/liebherr/xea/xea.c
+++ b/board/liebherr/xea/xea.c
@@ -48,6 +48,35 @@ DECLARE_GLOBAL_DATA_PTR;
* Functions
*/

+/*
+ * Reading the HW ID number for XEA SoM module
+ *
+ * GPIOs from Port 1 (GPIO1_15, GPIO1_16, GPIO1_17 and GPIO1_18)
+ * are used to store HW revision information.
+ * Reading of GPIOs values is performed before the Device Model is
+ * bring up as the proper DTB needs to be chosen first.
+ *
+ * Moreover, this approach is required as "single binary" configuration
+ * of U-Boot (imx28_xea_sb_defconfig) is NOT using SPL framework, so
+ * only minimal subset of functionality is provided when ID is read.
+ *
+ * Hence, the direct registers' access.
+ */
+#define XEA_SOM_HW_ID_GPIO_PORT (MXS_PINCTRL_BASE + (0x0900 + ((1) * 0x10)))
+#define XEA_SOM_REV_MASK GENMASK(18, 15)
+#define XEA_SOM_REV_SHIFT 15
+
+static inline u8 get_som_rev(void)
+{
+ struct mxs_register_32 *reg =
+ (struct mxs_register_32 *)XEA_SOM_HW_ID_GPIO_PORT;
+
+ u32 tmp = ~readl(&reg->reg);
+ u8 id = (tmp & XEA_SOM_REV_MASK) >> XEA_SOM_REV_SHIFT;
+
+ return id;
+}
+
static void init_clocks(void)
{
/* IO0 clock at 480MHz */
--
2.39.2