[PATCH] board: sifive: spl: Initialized the PWM setting in the SPL stage

[Nylon Chen]

From: Vincent Chen <vincent.chen at sifive.com>

LEDs and multiple fans can be controlled by SPL. This patch ensures
that all fans have been enabled in the SPL stage. In addition, the
LED's color will be set to yellow.

Signed-off-by: Vincent Chen <vincent.chen at sifive.com>
Co-developed-by: Nylon Chen <nylon.chen at sifive.com>
Signed-off-by: Nylon Chen <nylon.chen at sifive.com>
Co-developed-by: Zong Li <zong.li at sifve.com>
Signed-off-by: Zong Li <zong.li at sifve.com>
---
 arch/riscv/include/asm/arch-fu740/eeprom.h | 15 +++++++
 board/sifive/unmatched/spl.c               | 52 ++++++++++++++++++++++
 2 files changed, 67 insertions(+)
 create mode 100644 arch/riscv/include/asm/arch-fu740/eeprom.h

diff --git a/arch/riscv/include/asm/arch-fu740/eeprom.h b/arch/riscv/include/asm/arch-fu740/eeprom.h
new file mode 100644
index 0000000000..aaa02c6d2b
--- /dev/null
+++ b/arch/riscv/include/asm/arch-fu740/eeprom.h
@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2024 SiFive, Inc.
+ *
+ * Zong Li <zong.li at sifve.com>
+ */
+
+#ifndef _ASM_RISCV_EEPROM_H
+#define _ASM_RISCV_EEPROM_H
+
+#define PCB_REVISION_REV3      0x3
+
+u8 get_pcb_revision_from_eeprom(void);
+
+#endif /* _ASM_RISCV_EEPROM_H */
diff --git a/board/sifive/unmatched/spl.c b/board/sifive/unmatched/spl.c
index 7c0beedc08..6f459bd651 100644
--- a/board/sifive/unmatched/spl.c
+++ b/board/sifive/unmatched/spl.c
@@ -15,6 +15,29 @@
 #include <asm/gpio.h>
 #include <asm/arch/gpio.h>
 #include <asm/arch/spl.h>
+#include <linux/io.h>
+#include <asm/arch/eeprom.h>
+
+struct pwm_sifive_regs {
+	unsigned int cfg;       /* PWM configuration register */
+	unsigned int pad0;      /* Reserved */
+	unsigned int cnt;       /* PWM count register */
+	unsigned int pad1;      /* Reserved */
+	unsigned int pwms;      /* Scaled PWM count register */
+	unsigned int pad2;      /* Reserved */
+	unsigned int pad3;      /* Reserved */
+	unsigned int pad4;      /* Reserved */
+	unsigned int cmp0;      /* PWM 0 compare register */
+	unsigned int cmp1;      /* PWM 1 compare register */
+	unsigned int cmp2;      /* PWM 2 compare register */
+	unsigned int cmp3;      /* PWM 3 compare register */
+};
+
+#define PWM0_BASE               0x10020000
+#define PWM1_BASE               0x10021000
+#define PWM_CFG_INIT            0x1000
+#define PWM_CMP_ENABLE_VAL      0x0
+#define PWM_CMP_DISABLE_VAL     0xffff
 
 #define UBRDG_RESET	SIFIVE_GENERIC_GPIO_NR(0, 7)
 #define ULPI_RESET	SIFIVE_GENERIC_GPIO_NR(0, 9)
@@ -26,6 +49,33 @@
 #define MODE_SELECT_SD		0xb
 #define MODE_SELECT_MASK	GENMASK(3, 0)
 
+void spl_pwm_device_init(void)
+{
+	struct pwm_sifive_regs *pwm0, *pwm1;
+
+	pwm0 = (struct pwm_sifive_regs *)PWM0_BASE;
+	pwm1 = (struct pwm_sifive_regs *)PWM1_BASE;
+	writel(PWM_CMP_DISABLE_VAL, (void *)&pwm0->cmp0);
+
+	/* Set the 3-color PWM LEDs to yellow in SPL */
+	writel(PWM_CMP_ENABLE_VAL, (void *)&pwm0->cmp1);
+	writel(PWM_CMP_ENABLE_VAL, (void *)&pwm0->cmp2);
+	writel(PWM_CMP_DISABLE_VAL, (void *)&pwm0->cmp3);
+	writel(PWM_CFG_INIT, (void *)&pwm0->cfg);
+
+	/* Turn on all the fans, (J21), (J23) and (J24), on the unmatched board */
+	/* The SoC fan(J21) on the rev3 board cannot be controlled by PWM_COMP0,
+	 *            so here sets the initial value of PWM_COMP0 as DISABLE */
+	if (get_pcb_revision_from_eeprom() == PCB_REVISION_REV3)
+		writel(PWM_CMP_DISABLE_VAL, (void *)&pwm1->cmp1);
+	else
+		writel(PWM_CMP_ENABLE_VAL, (void *)&pwm1->cmp1);
+
+	writel(PWM_CMP_ENABLE_VAL, (void *)&pwm1->cmp2);
+	writel(PWM_CMP_ENABLE_VAL, (void *)&pwm1->cmp3);
+	writel(PWM_CFG_INIT, (void *)&pwm1->cfg);
+}
+
 static inline int spl_reset_device_by_gpio(const char *label, int pin, int low_width)
 {
 	int ret;
@@ -90,6 +140,8 @@ int spl_board_init_f(void)
 		goto end;
 	}
 
+	spl_pwm_device_init();
+
 	ret = spl_gemgxl_init();
 	if (ret) {
 		debug("Gigabit ethernet PHY (VSC8541) init failed: %d\n", ret);
-- 
2.34.1