ARM: uniphier: deassert RST_n of eMMC device for LD11/LD20

For LD11 and LD20 SoCs, the RST_n pin is asserted by default.  If
the EXT_CSD[162], bit[1:0] (RST_n_ENABLE) is fused, the eMMC device
would stay in the reset state until its RST_n pin is deasserted by
software.

Currently, this is cared by an ad-hoc way because the eMMC hardware
reset provider is not supported in U-Boot for now.  This code should
be re-written once the "mmc-pwrseq-emmc" binding is supported.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

arch/arm/mach-uniphier/board_init.c

@@ -165,6 +165,7 @@ static const struct uniphier_initdata uniphier_initdata[] = {
 		.nand_2cs = false,
 		.sbc_init = uniphier_ld11_sbc_init,
 		.pll_init = uniphier_ld20_pll_init,
+		.clk_init = uniphier_ld20_clk_init,
 		.misc_init = uniphier_ld20_misc_init,
 	},
 #endif

arch/arm/mach-uniphier/clk/Makefile

@@ -24,7 +24,7 @@ obj-$(CONFIG_ARCH_UNIPHIER_PRO5)	+= clk-pro5.o
 obj-$(CONFIG_ARCH_UNIPHIER_PXS2)	+= clk-pxs2.o
 obj-$(CONFIG_ARCH_UNIPHIER_LD6B)	+= clk-pxs2.o
 obj-$(CONFIG_ARCH_UNIPHIER_LD11)	+= clk-ld11.o pll-ld11.o
-obj-$(CONFIG_ARCH_UNIPHIER_LD20)	+= pll-ld20.o
+obj-$(CONFIG_ARCH_UNIPHIER_LD20)	+= clk-ld20.o pll-ld20.o
 obj-$(CONFIG_ARCH_UNIPHIER_PXS3)	+= pll-pxs3.o
 
 endif

arch/arm/mach-uniphier/clk/clk-ld11.c

@@ -13,6 +13,8 @@
 #include "../sc64-regs.h"
 #include "../sg-regs.h"
 
+#define SDCTRL_EMMC_HW_RESET	0x59810280
+
 void uniphier_ld11_clk_init(void)
 {
 	/* if booted from a device other than USB, without stand-by MPU */
@@ -28,6 +30,9 @@ void uniphier_ld11_clk_init(void)
 		writel(7, SG_ETPHYCNT);
 	}
 
+	/* TODO: use "mmc-pwrseq-emmc" */
+	writel(1, SDCTRL_EMMC_HW_RESET);
+
 #ifdef CONFIG_USB_EHCI
 	{
 		/* FIXME: the current clk driver can not handle parents */

arch/arm/mach-uniphier/clk/clk-ld20.c

@@ -0,0 +1,17 @@
+/*
+ * Copyright (C) 2017 Socionext Inc.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <linux/io.h>
+
+#include "../init.h"
+
+#define SDCTRL_EMMC_HW_RESET	0x59810280
+
+void uniphier_ld20_clk_init(void)
+{
+	/* TODO: use "mmc-pwrseq-emmc" */
+	writel(1, SDCTRL_EMMC_HW_RESET);
+}

arch/arm/mach-uniphier/init.h

@@ -118,6 +118,7 @@ void uniphier_pro4_clk_init(void);
 void uniphier_pro5_clk_init(void);
 void uniphier_pxs2_clk_init(void);
 void uniphier_ld11_clk_init(void);
+void uniphier_ld20_clk_init(void);
 
 unsigned int uniphier_boot_device_raw(void);
 int uniphier_pin_init(const char *pinconfig_name);