From: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Subject: spi: renesas-rpc: allow reading from large flashes

Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>

---
 drivers/spi/spi-renesas-rpc.c   |   26 ++++++++++++++++++++------
 include/linux/mfd/renesas-rpc.h |    2 ++
 2 files changed, 22 insertions(+), 6 deletions(-)

Index: renesas/drivers/spi/spi-renesas-rpc.c
===================================================================
--- renesas.orig/drivers/spi/spi-renesas-rpc.c
+++ renesas/drivers/spi/spi-renesas-rpc.c
@@ -264,14 +264,12 @@ static ssize_t rpc_spi_mem_dirmap_read(s
 {
 	struct rpc_spi *rpc =
 			spi_controller_get_devdata(desc->mem->spi->controller);
+	size_t _len = len;
 	int ret;
 
 	if (offs + desc->info.offset + len > U32_MAX)
 		return -EINVAL;
 
-	if (len > 0x4000000)
-		len = 0x4000000;
-
 	ret = rpc_spi_set_freq(rpc, desc->mem->spi->max_speed_hz);
 	if (ret)
 		return ret;
@@ -284,15 +282,31 @@ static ssize_t rpc_spi_mem_dirmap_read(s
 		     RPC_DRCR_RBE);
 
 	regmap_write(rpc->regmap, RPC_DRCMR, rpc->cmd);
-	regmap_write(rpc->regmap, RPC_DREAR, RPC_DREAR_EAC(1));
 	regmap_write(rpc->regmap, RPC_DROPR, 0);
 	regmap_write(rpc->regmap, RPC_DRENR, rpc->smenr);
 	regmap_write(rpc->regmap, RPC_DRDMCR, rpc->dummy);
 	regmap_write(rpc->regmap, RPC_DRDRENR, 0);
 
-	memcpy_fromio(buf, rpc->dirmap + desc->info.offset + offs, len);
+	while (len) {
+		loff_t from = offs & (RPC_DIRMAP_SIZE - 1);
+		size_t size = RPC_DIRMAP_SIZE - from;
+		u32 val = RPC_DREAR_EAC(1);
+
+		if (rpc->smenr & RPC_DRENR_ADE(8))
+			val |= RPC_DREAR_EAV(offs >> 25);
+		regmap_write(rpc->regmap, RPC_DREAR, val);
+
+		if (size > len)
+			size = len;
+
+		memcpy_fromio(buf, rpc->dirmap + desc->info.offset + from,
+			      size);
+		buf  += size;
+		offs += size;
+		len  -= size;
+	}
 
-	return len;
+	return _len;
 }
 
 static ssize_t rpc_spi_mem_dirmap_write(struct spi_mem_dirmap_desc *desc,
Index: renesas/include/linux/mfd/renesas-rpc.h
===================================================================
--- renesas.orig/include/linux/mfd/renesas-rpc.h
+++ renesas/include/linux/mfd/renesas-rpc.h
@@ -57,6 +57,7 @@
 #define RPC_DRCMR_OCMD(c)	(((c) & 0xFF) << 0)
 
 #define RPC_DREAR		0x0014	// R/W
+#define RPC_DREAR_EAV(v)	(((v) & 0xff) << 16)
 #define RPC_DREAR_EAC(c)	(((c) & 0x7) << 0)
 
 #define RPC_DROPR		0x0018	// R/W
@@ -140,6 +141,7 @@
 #define RPC_PHYOFFSET2		0x0084	// R/W
 #define RPC_PHYOFFSET2_OCTTMG(v) (((v) & 0x7) << 8)
 
+#define RPC_DIRMAP_SIZE		0x4000000
 #define RPC_WBUF_SIZE		256	// Write Buffer size
 
 struct rpc_mfd {