ARM: uniphier: support Debug UART
For ARM32 architecture, CONFIG_DEBUG_LL is available for early
low-level debugging (and actually UniPhier 32bit SoCs use it), but
ARM64 architecture does not support it. Instead, CONFIG_DEBUG_UART
is available as an architecture-independent debug facility.
This commit supports it on all the UniPhier SoCs (including the new
ARMv8 SoCs), which is very useful for new SoC bringups.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
diff --git a/arch/arm/mach-uniphier/debug-uart/debug-uart.c b/arch/arm/mach-uniphier/debug-uart/debug-uart.c
new file mode 100644
index 0000000..d884785
--- /dev/null
+++ b/arch/arm/mach-uniphier/debug-uart/debug-uart.c
@@ -0,0 +1,85 @@
+/*
+ * Copyright (C) 2016 Masahiro Yamada <yamada.masahiro@socionext.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+#include <debug_uart.h>
+#include <linux/io.h>
+#include <linux/serial_reg.h>
+
+#include "../soc-info.h"
+#include "debug-uart.h"
+
+#define UNIPHIER_UART_TX 0x00
+#define UNIPHIER_UART_LCR_MCR 0x10
+#define UNIPHIER_UART_LSR 0x14
+#define UNIPHIER_UART_LDR 0x24
+
+static void _debug_uart_putc(int c)
+{
+ void __iomem *base = (void __iomem *)CONFIG_DEBUG_UART_BASE;
+
+ while (!(readl(base + UNIPHIER_UART_LSR) & UART_LSR_THRE))
+ ;
+
+ writel(c, base + UNIPHIER_UART_TX);
+}
+
+void _debug_uart_init(void)
+{
+ void __iomem *base = (void __iomem *)CONFIG_DEBUG_UART_BASE;
+ unsigned int divisor;
+
+ switch (uniphier_get_soc_type()) {
+#if defined(CONFIG_ARCH_UNIPHIER_SLD3)
+ case SOC_UNIPHIER_SLD3:
+ divisor = uniphier_sld3_debug_uart_init();
+ break;
+#endif
+#if defined(CONFIG_ARCH_UNIPHIER_LD4)
+ case SOC_UNIPHIER_LD4:
+ divisor = uniphier_ld4_debug_uart_init();
+ break;
+#endif
+#if defined(CONFIG_ARCH_UNIPHIER_PRO4)
+ case SOC_UNIPHIER_PRO4:
+ divisor = uniphier_pro4_debug_uart_init();
+ break;
+#endif
+#if defined(CONFIG_ARCH_UNIPHIER_SLD8)
+ case SOC_UNIPHIER_SLD8:
+ divisor = uniphier_sld8_debug_uart_init();
+ break;
+#endif
+#if defined(CONFIG_ARCH_UNIPHIER_PRO5)
+ case SOC_UNIPHIER_PRO5:
+ divisor = uniphier_pro5_debug_uart_init();
+ break;
+#endif
+#if defined(CONFIG_ARCH_UNIPHIER_PXS2)
+ case SOC_UNIPHIER_PXS2:
+ divisor = uniphier_pxs2_debug_uart_init();
+ break;
+#endif
+#if defined(CONFIG_ARCH_UNIPHIER_LD6B)
+ case SOC_UNIPHIER_LD6B:
+ divisor = uniphier_ld6b_debug_uart_init();
+ break;
+#endif
+#if defined(CONFIG_ARCH_UNIPHIER_LD11) || defined(CONFIG_ARCH_UNIPHIER_LD20)
+ case SOC_UNIPHIER_LD11:
+ case SOC_UNIPHIER_LD20:
+ divisor = uniphier_ld20_debug_uart_init();
+ break;
+#endif
+ default:
+ return;
+ }
+
+ writel(UART_LCR_WLEN8 << 8, base + UNIPHIER_UART_LCR_MCR);
+
+ writel(divisor, base + UNIPHIER_UART_LDR);
+}
+DEBUG_UART_FUNCS