[U-Boot] [PATCH 14/19] stm32mp1: add syscfg initialization

[Patrick Delaunay]

Initialize the system configuration for basic boot
- update interconnect setting
- disable pull-down for boot pin
- enable High Speed Low Voltage Pad mode for SPI, SDMMC, ETH, QSPI
- activate I/O compensation

Done by SSBL = TF-A for trusted boot

Signed-off-by: Patrick Delaunay <patrick.delaunay at st.com>
---

 board/st/stm32mp1/stm32mp1.c | 130 ++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 129 insertions(+), 1 deletion(-)

diff --git a/board/st/stm32mp1/stm32mp1.c b/board/st/stm32mp1/stm32mp1.c
index d13793e..2829180 100644
--- a/board/st/stm32mp1/stm32mp1.c
+++ b/board/st/stm32mp1/stm32mp1.c
@@ -11,13 +11,47 @@
 #include <misc.h>
 #include <phy.h>
 #include <reset.h>
+#include <syscon.h>
 #include <usb.h>
-#include <asm/arch/stm32.h>
 #include <asm/io.h>
 #include <asm/gpio.h>
+#include <asm/arch/stm32.h>
 #include <power/regulator.h>
 #include <usb/dwc2_udc.h>
 
+/* SYSCFG registers */
+#define SYSCFG_BOOTR		0x00
+#define SYSCFG_PMCSETR		0x04
+#define SYSCFG_IOCTRLSETR	0x18
+#define SYSCFG_ICNR		0x1C
+#define SYSCFG_CMPCR		0x20
+#define SYSCFG_CMPENSETR	0x24
+#define SYSCFG_PMCCLRR		0x44
+
+#define SYSCFG_BOOTR_BOOT_MASK		GENMASK(2, 0)
+#define SYSCFG_BOOTR_BOOTPD_SHIFT	4
+
+#define SYSCFG_IOCTRLSETR_HSLVEN_TRACE		BIT(0)
+#define SYSCFG_IOCTRLSETR_HSLVEN_QUADSPI	BIT(1)
+#define SYSCFG_IOCTRLSETR_HSLVEN_ETH		BIT(2)
+#define SYSCFG_IOCTRLSETR_HSLVEN_SDMMC		BIT(3)
+#define SYSCFG_IOCTRLSETR_HSLVEN_SPI		BIT(4)
+
+#define SYSCFG_CMPCR_SW_CTRL		BIT(1)
+#define SYSCFG_CMPCR_READY		BIT(8)
+
+#define SYSCFG_CMPENSETR_MPU_EN		BIT(0)
+
+#define SYSCFG_PMCSETR_ETH_CLK_SEL	BIT(16)
+#define SYSCFG_PMCSETR_ETH_REF_CLK_SEL	BIT(17)
+
+#define SYSCFG_PMCSETR_ETH_SELMII	BIT(20)
+
+#define SYSCFG_PMCSETR_ETH_SEL_MASK	GENMASK(23, 21)
+#define SYSCFG_PMCSETR_ETH_SEL_GMII_MII	(0 << 21)
+#define SYSCFG_PMCSETR_ETH_SEL_RGMII	(1 << 21)
+#define SYSCFG_PMCSETR_ETH_SEL_RMII	(4 << 21)
+
 /*
  * Get a global data pointer
  */
@@ -270,6 +304,98 @@ int board_usb_cleanup(int index, enum usb_init_type init)
 	return 0;
 }
 
+static void sysconf_init(void)
+{
+#ifndef CONFIG_STM32MP1_TRUSTED
+	u8 *syscfg;
+#ifdef CONFIG_DM_REGULATOR
+	struct udevice *pwr_dev;
+	struct udevice *pwr_reg;
+	struct udevice *dev;
+	int ret;
+	u32 otp = 0;
+#endif
+	u32 bootr;
+
+	syscfg = (u8 *)syscon_get_first_range(STM32MP_SYSCON_SYSCFG);
+
+	/* interconnect update : select master using the port 1 */
+	/* LTDC = AXI_M9 */
+	/* GPU  = AXI_M8 */
+	/* today information is hardcoded in U-Boot */
+	writel(BIT(9), syscfg + SYSCFG_ICNR);
+
+	/* disable Pull-Down for boot pin connected to VDD */
+	bootr = readl(syscfg + SYSCFG_BOOTR);
+	bootr &= ~(SYSCFG_BOOTR_BOOT_MASK << SYSCFG_BOOTR_BOOTPD_SHIFT);
+	bootr |= (bootr & SYSCFG_BOOTR_BOOT_MASK) << SYSCFG_BOOTR_BOOTPD_SHIFT;
+	writel(bootr, syscfg + SYSCFG_BOOTR);
+
+#ifdef CONFIG_DM_REGULATOR
+	/* High Speed Low Voltage Pad mode Enable for SPI, SDMMC, ETH, QSPI
+	 * and TRACE. Needed above ~50MHz and conditioned by AFMUX selection.
+	 * The customer will have to disable this for low frequencies
+	 * or if AFMUX is selected but the function not used, typically for
+	 * TRACE. Otherwise, impact on power consumption.
+	 *
+	 * WARNING:
+	 *   enabling High Speed mode while VDD>2.7V
+	 *   with the OTP product_below_2v5 (OTP 18, BIT 13)
+	 *   erroneously set to 1 can damage the IC!
+	 *   => U-Boot set the register only if VDD < 2.7V (in DT)
+	 *      but this value need to be consistent with board design
+	 */
+	ret = syscon_get_by_driver_data(STM32MP_SYSCON_PWR, &pwr_dev);
+	if (!ret) {
+		ret = uclass_get_device_by_driver(UCLASS_MISC,
+						  DM_GET_DRIVER(stm32mp_bsec),
+						  &dev);
+		if (ret) {
+			pr_err("Can't find stm32mp_bsec driver\n");
+			return;
+		}
+
+		ret = misc_read(dev, STM32_BSEC_SHADOW(18), &otp, 4);
+		if (!ret)
+			otp = otp & BIT(13);
+
+		/* get VDD = pwr-supply */
+		ret = device_get_supply_regulator(pwr_dev, "pwr-supply",
+						  &pwr_reg);
+
+		/* check if VDD is Low Voltage */
+		if (!ret) {
+			if (regulator_get_value(pwr_reg) < 2700000) {
+				writel(SYSCFG_IOCTRLSETR_HSLVEN_TRACE |
+				       SYSCFG_IOCTRLSETR_HSLVEN_QUADSPI |
+				       SYSCFG_IOCTRLSETR_HSLVEN_ETH |
+				       SYSCFG_IOCTRLSETR_HSLVEN_SDMMC |
+				       SYSCFG_IOCTRLSETR_HSLVEN_SPI,
+				       syscfg + SYSCFG_IOCTRLSETR);
+
+				if (!otp)
+					pr_err("product_below_2v5=0: HSLVEN protected by HW\n");
+			} else {
+				if (otp)
+					pr_err("product_below_2v5=1: HSLVEN update is destructive, no update as VDD>2.7V\n");
+			}
+		} else {
+			debug("VDD unknown");
+		}
+	}
+#endif
+
+	/* activate automatic I/O compensation
+	 * warning: need to ensure CSI enabled and ready in clock driver
+	 */
+	writel(SYSCFG_CMPENSETR_MPU_EN, syscfg + SYSCFG_CMPENSETR);
+
+	while (!(readl(syscfg + SYSCFG_CMPCR) & SYSCFG_CMPCR_READY))
+		;
+	clrbits_le32(syscfg + SYSCFG_CMPCR, SYSCFG_CMPCR_SW_CTRL);
+#endif
+}
+
 /* board dependent setup after realloc */
 int board_init(void)
 {
@@ -278,6 +404,8 @@ int board_init(void)
 
 	board_key_check();
 
+	sysconf_init();
+
 	if (IS_ENABLED(CONFIG_LED))
 		led_default_state();
 
-- 
2.7.4