ARM: UniPhier: add UART initialization routine for low-level debug

The low-level debugging functions are useful to debug the early boot
stage where the full UART driver is not available.

UniPhier SoCs need to initialize the UART port 0 to use this feature.
The initialization routine is called at the very entry of the
lowlevel_init().

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>

diff --git a/arch/arm/cpu/armv7/uniphier/lowlevel_init.S b/arch/arm/cpu/armv7/uniphier/lowlevel_init.S
index 0ea12d3cfc6ea6ffeb0db2df61397240baf5b87b..c208ab67a180188a0d4f2b46330a1edaa3e0efc2 100644 (file)
--- a/arch/arm/cpu/armv7/uniphier/lowlevel_init.S
+++ b/arch/arm/cpu/armv7/uniphier/lowlevel_init.S
@@ -26,6 +26,10 @@ ENTRY(lowlevel_init)
        orr     r0, r0, #(CR_C | CR_M)          @ enable MMU and Dcache
        mcr     p15, 0, r0, c1, c0, 0
 
+#ifdef CONFIG_DEBUG_LL
+       bl      setup_lowlevel_debug
+#endif
+
        /*
         * Now we are using the page table embedded in the Boot ROM.
         * It is not handy since it is not a straight mapped table for sLD3.

diff --git a/arch/arm/cpu/armv7/uniphier/ph1-ld4/Makefile b/arch/arm/cpu/armv7/uniphier/ph1-ld4/Makefile
index 8794629b2ab135938f7931482655a28e07fb9a52..07529061213e6be38ca5e7de7fa0ddda86c93c70 100644 (file)
--- a/arch/arm/cpu/armv7/uniphier/ph1-ld4/Makefile
+++ b/arch/arm/cpu/armv7/uniphier/ph1-ld4/Makefile
@@ -5,6 +5,7 @@
 obj-$(CONFIG_DISPLAY_BOARDINFO) += board_info.o
 obj-$(if $(CONFIG_OF_CONTROL),,y) += platdevice.o
 obj-y += boot-mode.o
+obj-$(CONFIG_DEBUG_LL) += lowlevel_debug.o
 obj-$(CONFIG_SOC_INIT) += bcu_init.o sbc_init.o sg_init.o pll_init.o \
                                                                clkrst_init.o
 obj-$(CONFIG_BOARD_POSTCLK_INIT) += pinctrl.o

diff --git a/arch/arm/cpu/armv7/uniphier/ph1-ld4/lowlevel_debug.S b/arch/arm/cpu/armv7/uniphier/ph1-ld4/lowlevel_debug.S
new file mode 100644 (file)
index 0000000..c0778a0
--- /dev/null
+++ b/arch/arm/cpu/armv7/uniphier/ph1-ld4/lowlevel_debug.S
@@ -0,0 +1,29 @@
+/*
+ * On-chip UART initializaion for low-level debugging
+ *
+ * Copyright (C) 2014 Panasonic Corporation
+ *   Author: Masahiro Yamada <yamada.m@jp.panasonic.com>
+ *
+ * SPDX-License-Identifier:    GPL-2.0+
+ */
+
+#include <linux/linkage.h>
+#include <asm/arch/sg-regs.h>
+
+#define UART_CLK               36864000
+#include <asm/arch/debug-uart.S>
+
+ENTRY(setup_lowlevel_debug)
+               init_debug_uart r0, r1, r2
+
+               /* UART Port 0 */
+               set_pinsel      85, 1, r0, r1
+               set_pinsel      88, 1, r0, r1
+
+               ldr             r0, =SG_IECTRL
+               ldr             r1, [r0]
+               orr             r1, r1, #1
+               str             r1, [r0]
+
+               mov             pc, lr
+ENDPROC(setup_lowlevel_debug)

diff --git a/arch/arm/cpu/armv7/uniphier/ph1-pro4/Makefile b/arch/arm/cpu/armv7/uniphier/ph1-pro4/Makefile
index cee78781f6326ff8bcbfc1327e2518c6fffca30d..8206e2a3542774e0133525825c95e7238f3a1657 100644 (file)
--- a/arch/arm/cpu/armv7/uniphier/ph1-pro4/Makefile
+++ b/arch/arm/cpu/armv7/uniphier/ph1-pro4/Makefile
@@ -5,6 +5,7 @@
 obj-$(CONFIG_DISPLAY_BOARDINFO) += board_info.o
 obj-$(if $(CONFIG_OF_CONTROL),,y) += platdevice.o
 obj-y += boot-mode.o
+obj-$(CONFIG_DEBUG_LL) += lowlevel_debug.o
 obj-$(CONFIG_SOC_INIT) += sbc_init.o sg_init.o pll_init.o clkrst_init.o
 obj-$(CONFIG_BOARD_POSTCLK_INIT) += pinctrl.o
 obj-$(CONFIG_DRAM_INIT) += pll_spectrum.o umc_init.o ddrphy_init.o

diff --git a/arch/arm/cpu/armv7/uniphier/ph1-pro4/lowlevel_debug.S b/arch/arm/cpu/armv7/uniphier/ph1-pro4/lowlevel_debug.S
new file mode 100644 (file)
index 0000000..a793b7c
--- /dev/null
+++ b/arch/arm/cpu/armv7/uniphier/ph1-pro4/lowlevel_debug.S
@@ -0,0 +1,39 @@
+/*
+ * On-chip UART initializaion for low-level debugging
+ *
+ * Copyright (C) 2014 Panasonic Corporation
+ *   Author: Masahiro Yamada <yamada.m@jp.panasonic.com>
+ *
+ * SPDX-License-Identifier:    GPL-2.0+
+ */
+
+#include <linux/linkage.h>
+#include <asm/arch/sc-regs.h>
+#include <asm/arch/sg-regs.h>
+
+#define UART_CLK               73728000
+#include <asm/arch/debug-uart.S>
+
+ENTRY(setup_lowlevel_debug)
+               ldr             r0, =SC_CLKCTRL
+               ldr             r1, [r0]
+               orr             r1, r1, #SC_CLKCTRL_CLK_PERI
+               str             r1, [r0]
+
+               init_debug_uart r0, r1, r2
+
+               /* UART Port 0 */
+               set_pinsel      127, 0, r0, r1
+               set_pinsel      128, 0, r0, r1
+
+               ldr             r0, =SG_LOADPINCTRL
+               mov             r1, #1
+               str             r1, [r0]
+
+               ldr             r0, =SG_IECTRL
+               ldr             r1, [r0]
+               orr             r1, r1, #1
+               str             r1, [r0]
+
+               mov             pc, lr
+ENDPROC(setup_lowlevel_debug)

diff --git a/arch/arm/cpu/armv7/uniphier/ph1-sld8/Makefile b/arch/arm/cpu/armv7/uniphier/ph1-sld8/Makefile
index 8794629b2ab135938f7931482655a28e07fb9a52..07529061213e6be38ca5e7de7fa0ddda86c93c70 100644 (file)
--- a/arch/arm/cpu/armv7/uniphier/ph1-sld8/Makefile
+++ b/arch/arm/cpu/armv7/uniphier/ph1-sld8/Makefile
@@ -5,6 +5,7 @@
 obj-$(CONFIG_DISPLAY_BOARDINFO) += board_info.o
 obj-$(if $(CONFIG_OF_CONTROL),,y) += platdevice.o
 obj-y += boot-mode.o
+obj-$(CONFIG_DEBUG_LL) += lowlevel_debug.o
 obj-$(CONFIG_SOC_INIT) += bcu_init.o sbc_init.o sg_init.o pll_init.o \
                                                                clkrst_init.o
 obj-$(CONFIG_BOARD_POSTCLK_INIT) += pinctrl.o

diff --git a/arch/arm/cpu/armv7/uniphier/ph1-sld8/lowlevel_debug.S b/arch/arm/cpu/armv7/uniphier/ph1-sld8/lowlevel_debug.S
new file mode 100644 (file)
index 0000000..a413e5f
--- /dev/null
+++ b/arch/arm/cpu/armv7/uniphier/ph1-sld8/lowlevel_debug.S
@@ -0,0 +1,29 @@
+/*
+ * On-chip UART initializaion for low-level debugging
+ *
+ * Copyright (C) 2014 Panasonic Corporation
+ *   Author: Masahiro Yamada <yamada.m@jp.panasonic.com>
+ *
+ * SPDX-License-Identifier:    GPL-2.0+
+ */
+
+#include <linux/linkage.h>
+#include <asm/arch/sg-regs.h>
+
+#define UART_CLK               80000000
+#include <asm/arch/debug-uart.S>
+
+ENTRY(setup_lowlevel_debug)
+               init_debug_uart r0, r1, r2
+
+               /* UART Port 0 */
+               set_pinsel      70, 3, r0, r1
+               set_pinsel      71, 3, r0, r1
+
+               ldr             r0, =SG_IECTRL
+               ldr             r1, [r0]
+               orr             r1, r1, #1
+               str             r1, [r0]
+
+               mov             pc, lr
+ENDPROC(setup_lowlevel_debug)

diff --git a/arch/arm/include/asm/arch-uniphier/debug-uart.S b/arch/arm/include/asm/arch-uniphier/debug-uart.S
new file mode 100644 (file)
index 0000000..af55fee
--- /dev/null
+++ b/arch/arm/include/asm/arch-uniphier/debug-uart.S
@@ -0,0 +1,24 @@
+/*
+ * Copyright (C) 2014 Panasonic Corporation
+ *   Author: Masahiro Yamada <yamada.m@jp.panasonic.com>
+ *
+ * SPDX-License-Identifier:    GPL-2.0+
+ */
+
+#include <linux/serial_reg.h>
+
+#if !defined(CONFIG_DEBUG_SEMIHOSTING)
+#include CONFIG_DEBUG_LL_INCLUDE
+#endif
+
+#define BAUDRATE               115200
+#define DIV_ROUND(x, d)                (((x) + ((d) / 2)) / (d))
+#define DIVISOR                        DIV_ROUND(UART_CLK, 16 * BAUDRATE)
+
+       .macro          init_debug_uart, ra, rb, rc
+       addruart        \ra, \rb, \rc
+       mov             \rb, #UART_LCR_WLEN8
+       strb            \rb, [\ra, #0x11]
+       ldr             \rb, =DIVISOR
+       str             \rb, [\ra, #0x24]
+       .endm