ARM: uniphier: detect RAM size by decoding HW register instead of DT

U-Boot needs to set up available memory area(s) in dram_init() and
dram_init_banksize().  It is platform-dependent how to detect the
memory banks.  Currently, UniPhier adopts the memory banks _alleged_
by DT.  This is based on the assumption that users bind a correct DT
in their build process.

Come to think of it, the DRAM controller has already been set up
before U-Boot is entered (because U-Boot runs on DRAM).  So, the
DRAM controller setup register seems a more reliable source of any
information about DRAM stuff.  The DRAM banks are initialized by
preliminary firmware (SPL, ARM Trusted Firmware BL2, or whatever),
so this means the source of the reliability is shifted from Device
Tree to such early-stage firmware.  However, if the DRAM controller
is wrongly configured, the system will crash.  If your system is
running, the DRAM setup register is very likely to provide the
correct DRAM mapping.

Decode the SG_MEMCONF register to get the available DRAM banks.
The dram_init() and dram_init_banksize() need similar decoding.
It would be nice if dram_init_banksize() could reuse the outcome
of dram_init(), but global variables are unavailable at this stage
because the .bss section is available only after the relocation.
As a result, SG_MEMCONF must be checked twice, but a new helper
uniphier_memconf_decode() will help to avoid code duplication.

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

arch/arm/mach-uniphier/dram_init.c

@@ -1,87 +1,243 @@
 /*
- * Copyright (C) 2012-2015 Masahiro Yamada <yamada.masahiro@socionext.com>
+ * Copyright (C) 2012-2015 Panasonic Corporation
+ * Copyright (C) 2015-2017 Socionext Inc.
+ *   Author: Masahiro Yamada <yamada.masahiro@socionext.com>
  *
  * SPDX-License-Identifier:	GPL-2.0+
  */
 
 #include <common.h>
-#include <libfdt.h>
 #include <fdtdec.h>
 #include <linux/errno.h>
+#include <linux/sizes.h>
 
 #include "init.h"
+#include "sg-regs.h"
 #include "soc-info.h"
 
 DECLARE_GLOBAL_DATA_PTR;
 
-static const void *get_memory_reg_prop(const void *fdt, int *lenp)
+struct uniphier_memif_data {
+	unsigned int soc_id;
+	unsigned long sparse_ch1_base;
+	int have_ch2;
+};
+
+static const struct uniphier_memif_data uniphier_memif_data[] = {
+	{
+		.soc_id = UNIPHIER_SLD3_ID,
+		.sparse_ch1_base = 0xc0000000,
+		/*
+		 * In fact, SLD3 has DRAM ch2, but the memory regions for ch1
+		 * and ch2 overlap, and host cannot get access to them at the
+		 * same time.  Hide the ch2 from U-Boot.
+		 */
+	},
+	{
+		.soc_id = UNIPHIER_LD4_ID,
+		.sparse_ch1_base = 0xc0000000,
+	},
+	{
+		.soc_id = UNIPHIER_PRO4_ID,
+		.sparse_ch1_base = 0xa0000000,
+	},
+	{
+		.soc_id = UNIPHIER_SLD8_ID,
+		.sparse_ch1_base = 0xc0000000,
+	},
+	{
+		.soc_id = UNIPHIER_PRO5_ID,
+		.sparse_ch1_base = 0xc0000000,
+	},
+	{
+		.soc_id = UNIPHIER_PXS2_ID,
+		.sparse_ch1_base = 0xc0000000,
+		.have_ch2 = 1,
+	},
+	{
+		.soc_id = UNIPHIER_LD6B_ID,
+		.sparse_ch1_base = 0xc0000000,
+		.have_ch2 = 1,
+	},
+	{
+		.soc_id = UNIPHIER_LD11_ID,
+		.sparse_ch1_base = 0xc0000000,
+	},
+	{
+		.soc_id = UNIPHIER_LD20_ID,
+		.sparse_ch1_base = 0xc0000000,
+		.have_ch2 = 1,
+	},
+	{
+		.soc_id = UNIPHIER_PXS3_ID,
+		.sparse_ch1_base = 0xc0000000,
+		.have_ch2 = 1,
+	},
+};
+UNIPHIER_DEFINE_SOCDATA_FUNC(uniphier_get_memif_data, uniphier_memif_data)
+
+static int uniphier_memconf_decode(struct uniphier_dram_ch *dram_ch)
 {
-	int offset;
+	const struct uniphier_memif_data *data;
+	unsigned long size;
+	u32 val;
 
-	offset = fdt_path_offset(fdt, "/memory");
-	if (offset < 0)
-		return NULL;
+	data = uniphier_get_memif_data();
+	if (!data) {
+		pr_err("unsupported SoC\n");
+		return -EINVAL;
+	}
 
-	return fdt_getprop(fdt, offset, "reg", lenp);
-}
+	val = readl(SG_MEMCONF);
 
-int dram_init(void)
-{
-	const void *fdt = gd->fdt_blob;
-	const fdt32_t *val;
-	int ac, sc, len;
-
-	ac = fdt_address_cells(fdt, 0);
-	sc = fdt_size_cells(fdt, 0);
-	if (ac < 0 || sc < 1 || sc > 2) {
-		printf("invalid address/size cells\n");
+	/* set up ch0 */
+	dram_ch[0].base = CONFIG_SYS_SDRAM_BASE;
+
+	switch (val & SG_MEMCONF_CH0_SZ_MASK) {
+	case SG_MEMCONF_CH0_SZ_64M:
+		size = SZ_64M;
+		break;
+	case SG_MEMCONF_CH0_SZ_128M:
+		size = SZ_128M;
+		break;
+	case SG_MEMCONF_CH0_SZ_256M:
+		size = SZ_256M;
+		break;
+	case SG_MEMCONF_CH0_SZ_512M:
+		size = SZ_512M;
+		break;
+	case SG_MEMCONF_CH0_SZ_1G:
+		size = SZ_1G;
+		break;
+	default:
+		pr_err("error: invald value is set to MEMCONF ch0 size\n");
 		return -EINVAL;
 	}
 
-	val = get_memory_reg_prop(fdt, &len);
-	if (len / sizeof(*val) < ac + sc)
+	if ((val & SG_MEMCONF_CH0_NUM_MASK) == SG_MEMCONF_CH0_NUM_2)
+		size *= 2;
+
+	dram_ch[0].size = size;
+
+	/* set up ch1 */
+	dram_ch[1].base = dram_ch[0].base + size;
+
+	if (val & SG_MEMCONF_SPARSEMEM) {
+		if (dram_ch[1].base > data->sparse_ch1_base) {
+			pr_warn("Sparse mem is enabled, but ch0 and ch1 overlap\n");
+			pr_warn("Only ch0 is available\n");
+			dram_ch[1].base = 0;
+			return 0;
+		}
+
+		dram_ch[1].base = data->sparse_ch1_base;
+	}
+
+	switch (val & SG_MEMCONF_CH1_SZ_MASK) {
+	case SG_MEMCONF_CH1_SZ_64M:
+		size = SZ_64M;
+		break;
+	case SG_MEMCONF_CH1_SZ_128M:
+		size = SZ_128M;
+		break;
+	case SG_MEMCONF_CH1_SZ_256M:
+		size = SZ_256M;
+		break;
+	case SG_MEMCONF_CH1_SZ_512M:
+		size = SZ_512M;
+		break;
+	case SG_MEMCONF_CH1_SZ_1G:
+		size = SZ_1G;
+		break;
+	default:
+		pr_err("error: invald value is set to MEMCONF ch1 size\n");
 		return -EINVAL;
+	}
+
+	if ((val & SG_MEMCONF_CH1_NUM_MASK) == SG_MEMCONF_CH1_NUM_2)
+		size *= 2;
 
-	val += ac;
+	dram_ch[1].size = size;
 
-	gd->ram_size = fdtdec_get_number(val, sc);
+	if (!data->have_ch2)
+		return 0;
 
-	debug("DRAM size = %08lx\n", (unsigned long)gd->ram_size);
+	/* set up ch2 */
+	dram_ch[2].base = dram_ch[1].base + size;
+
+	switch (val & SG_MEMCONF_CH2_SZ_MASK) {
+	case SG_MEMCONF_CH2_SZ_64M:
+		size = SZ_64M;
+		break;
+	case SG_MEMCONF_CH2_SZ_128M:
+		size = SZ_128M;
+		break;
+	case SG_MEMCONF_CH2_SZ_256M:
+		size = SZ_256M;
+		break;
+	case SG_MEMCONF_CH2_SZ_512M:
+		size = SZ_512M;
+		break;
+	case SG_MEMCONF_CH2_SZ_1G:
+		size = SZ_1G;
+		break;
+	default:
+		pr_err("error: invald value is set to MEMCONF ch2 size\n");
+		return -EINVAL;
+	}
+
+	if ((val & SG_MEMCONF_CH2_NUM_MASK) == SG_MEMCONF_CH2_NUM_2)
+		size *= 2;
+
+	dram_ch[2].size = size;
 
 	return 0;
 }
 
-void dram_init_banksize(void)
+int dram_init(void)
 {
-	const void *fdt = gd->fdt_blob;
-	const fdt32_t *val;
-	int ac, sc, cells, len, i;
-
-	val = get_memory_reg_prop(fdt, &len);
-	if (len < 0)
-		return;
-
-	ac = fdt_address_cells(fdt, 0);
-	sc = fdt_size_cells(fdt, 0);
-	if (ac < 1 || sc > 2 || sc < 1 || sc > 2) {
-		printf("invalid address/size cells\n");
-		return;
+	struct uniphier_dram_ch dram_ch[UNIPHIER_MAX_NR_DRAM_CH] = {};
+	int ret, i;
+
+	gd->ram_size = 0;
+
+	ret = uniphier_memconf_decode(dram_ch);
+	if (ret)
+		return ret;
+
+	for (i = 0; i < ARRAY_SIZE(dram_ch); i++) {
+
+		if (!dram_ch[i].size)
+			break;
+
+		/*
+		 * U-Boot relocates itself to the tail of the memory region,
+		 * but it does not expect sparse memory.  We use the first
+		 * contiguous chunk here.
+		 */
+		if (i > 0 &&
+		    dram_ch[i - 1].base + dram_ch[i - 1].size < dram_ch[i].base)
+			break;
+
+		gd->ram_size += dram_ch[i].size;
 	}
 
-	cells = ac + sc;
+	return 0;
+}
+
+void dram_init_banksize(void)
+{
+	struct uniphier_dram_ch dram_ch[UNIPHIER_MAX_NR_DRAM_CH] = {};
+	int i;
 
-	len /= sizeof(*val);
+	uniphier_memconf_decode(dram_ch);
 
-	for (i = 0; i < CONFIG_NR_DRAM_BANKS && len >= cells;
-	     i++, len -= cells) {
-		gd->bd->bi_dram[i].start = fdtdec_get_number(val, ac);
-		val += ac;
-		gd->bd->bi_dram[i].size = fdtdec_get_number(val, sc);
-		val += sc;
+	for (i = 0; i < ARRAY_SIZE(dram_ch); i++) {
+		if (i >= ARRAY_SIZE(gd->bd->bi_dram))
+			break;
 
-		debug("DRAM bank %d: start = %08lx, size = %08lx\n",
-		      i, (unsigned long)gd->bd->bi_dram[i].start,
-		      (unsigned long)gd->bd->bi_dram[i].size);
+		gd->bd->bi_dram[i].start = dram_ch[i].base;
+		gd->bd->bi_dram[i].size = dram_ch[i].size;
 	}
 }
 

arch/arm/mach-uniphier/init.h

@@ -124,6 +124,7 @@ int uniphier_pin_init(const char *pinconfig_name);
 void uniphier_smp_kick_all_cpus(void);
 void cci500_init(int nr_slaves);
 
+#define pr_warn(fmt, args...)	printf(fmt, ##args)
 #define pr_err(fmt, args...)	printf(fmt, ##args)
 
 #endif /* __MACH_INIT_H */

include/configs/uniphier.h

@@ -236,7 +236,7 @@
 #define CONFIG_SYS_BOOTMAPSZ			0x20000000
 
 #define CONFIG_SYS_SDRAM_BASE		0x80000000
-#define CONFIG_NR_DRAM_BANKS		2
+#define CONFIG_NR_DRAM_BANKS		3
 /* for LD20; the last 64 byte is used for dynamic DDR PHY training */
 #define CONFIG_SYS_MEM_TOP_HIDE		64