[PATCH RFC 0/2] Add Renesas RPC-IF support

[PATCH RFC 0/2] Add Renesas RPC-IF support

[Sergei Shtylyov]

Hello!

Here's a set of 2 patches against Linus' repo. Renesas Reduced Pin Count
Interface (RPC-IF) allows a SPI flash or HyperFlash connected to the SoC
to be accessed via the external address space read mode or the manual mode.
The memory controller driver for RPC-IF registers either the SPI or HyperFLash
subdevice, depending on the contents of the device tree subnode; it also
provides the abstract "back end" API that can be used by the "front end"
SPI/MTD drivers to talk to the real hardware...

Based on the original patch by Mason Yang <masonccyang@mxic.com.tw>.

[1/2] dt-bindings: memory: document Renesas RPC-IF bindings
[2/2] memory: add Renesas RPC-IF driver

MBR, Sergei

[PATCH RFC 1/2] dt-bindings: memory: document Renesas RPC-IF bindings

[Sergei Shtylyov]

Renesas Reduced Pin Count Interface (RPC-IF) allows a SPI flash or
HyperFlash connected to the SoC to be accessed via the external address
space read mode or the manual mode.

Document the device tree bindings for the Renesas RPC-IF found in the R-Car
gen3 SoCs.

Based on the original patch by Mason Yang <masonccyang@mxic.com.tw>.

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

---
 Documentation/devicetree/bindings/memory-controllers/renesas,rpc-if.txt |   52 ++++++++++
 1 file changed, 52 insertions(+)

Index: linux/Documentation/devicetree/bindings/memory-controllers/renesas,rpc-if.txt
===================================================================
--- /dev/null
+++ linux/Documentation/devicetree/bindings/memory-controllers/renesas,rpc-if.txt
@@ -0,0 +1,52 @@
+Renesas Reduced Pin Count Interface (RPC-IF)
+--------------------------------------------
+
+Renesas RPC-IF allows a SPI flash or HyperFlash connected to the SoC to
+be accessed via the external address space read mode or the manual mode.
+
+Required properties:
+- compatible: should be an SoC-specific compatible value, followed by
+		"renesas,rcar-gen3-rpc-if" as a fallback.
+		supported SoC-specific values are:
+		"renesas,r8a77980-rpc-if" (R-Car V3H),
+		"renesas,r8a77995-rpc-if" (R-Car D3).
+- reg: should list 3 register areas:
+	1st for the RPC-IF registers,
+	2nd for the direct mapping read mode,
+	3rd for the write buffer area.
+- reg-names: should contain "regs", "dirmap", and "wbuf".
+- clocks: should contain the clock phandle/specifier pair for the module clock.
+- power-domains: should contain the power domain phandle/specifier pair.
+- resets: should contain the reset controller phandle/specifier pair.
+- #address-cells: should be 1.
+- #size-cells: should be 0.
+
+The flash chip itself should be represented by a subnode of the RPC-IF node.
+The flash interface is selected based on the "compatible" property of this
+subnode:
+- if it contains "jedec,spi-nor", then SPI is used;
+- if it contains "cfi-flash", then HyperFlash is used.
+
+Example:
+
+	rpc: spi@ee200000 {
+		compatible = "renesas,r8a77995-rpc-if",
+			     "renesas,rcar-gen3-rpc-if";
+		reg = <0 0xee200000 0 0x200>,
+		      <0 0x08000000 0 0x4000000>,
+		      <0 0xee208000 0 0x100>;
+		reg-names = "regs", "dirmap", "wbuf";
+		clocks = <&cpg CPG_MOD 917>;
+		power-domains = <&sysc R8A77995_PD_ALWAYS_ON>;
+		resets = <&cpg 917>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		flash@0 {
+			compatible = "jedec,spi-nor";
+			reg = <0>;
+			spi-max-frequency = <40000000>;
+			spi-tx-bus-width = <1>;
+			spi-rx-bus-width = <1>;
+		};
+	};

Re: [PATCH RFC 1/2] dt-bindings: memory: document Renesas RPC-IF bindings

[Rob Herring]

On Tue, Dec 10, 2019 at 10:37:34PM +0300, Sergei Shtylyov wrote:
> Renesas Reduced Pin Count Interface (RPC-IF) allows a SPI flash or
> HyperFlash connected to the SoC to be accessed via the external address
> space read mode or the manual mode.
> 
> Document the device tree bindings for the Renesas RPC-IF found in the R-Car
> gen3 SoCs.
> 
> Based on the original patch by Mason Yang <masonccyang@mxic.com.tw>.
> 
> Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
> 
> ---
>  Documentation/devicetree/bindings/memory-controllers/renesas,rpc-if.txt |   52 ++++++++++
>  1 file changed, 52 insertions(+)

Please convert to DT schema.

> 
> Index: linux/Documentation/devicetree/bindings/memory-controllers/renesas,rpc-if.txt
> ===================================================================
> --- /dev/null
> +++ linux/Documentation/devicetree/bindings/memory-controllers/renesas,rpc-if.txt
> @@ -0,0 +1,52 @@
> +Renesas Reduced Pin Count Interface (RPC-IF)
> +--------------------------------------------
> +
> +Renesas RPC-IF allows a SPI flash or HyperFlash connected to the SoC to
> +be accessed via the external address space read mode or the manual mode.
> +
> +Required properties:
> +- compatible: should be an SoC-specific compatible value, followed by
> +		"renesas,rcar-gen3-rpc-if" as a fallback.
> +		supported SoC-specific values are:
> +		"renesas,r8a77980-rpc-if" (R-Car V3H),
> +		"renesas,r8a77995-rpc-if" (R-Car D3).
> +- reg: should list 3 register areas:
> +	1st for the RPC-IF registers,
> +	2nd for the direct mapping read mode,
> +	3rd for the write buffer area.
> +- reg-names: should contain "regs", "dirmap", and "wbuf".
> +- clocks: should contain the clock phandle/specifier pair for the module clock.
> +- power-domains: should contain the power domain phandle/specifier pair.
> +- resets: should contain the reset controller phandle/specifier pair.
> +- #address-cells: should be 1.
> +- #size-cells: should be 0.
> +
> +The flash chip itself should be represented by a subnode of the RPC-IF node.
> +The flash interface is selected based on the "compatible" property of this
> +subnode:
> +- if it contains "jedec,spi-nor", then SPI is used;
> +- if it contains "cfi-flash", then HyperFlash is used.
> +
> +Example:
> +
> +	rpc: spi@ee200000 {
> +		compatible = "renesas,r8a77995-rpc-if",
> +			     "renesas,rcar-gen3-rpc-if";
> +		reg = <0 0xee200000 0 0x200>,
> +		      <0 0x08000000 0 0x4000000>,
> +		      <0 0xee208000 0 0x100>;
> +		reg-names = "regs", "dirmap", "wbuf";
> +		clocks = <&cpg CPG_MOD 917>;
> +		power-domains = <&sysc R8A77995_PD_ALWAYS_ON>;
> +		resets = <&cpg 917>;
> +		#address-cells = <1>;
> +		#size-cells = <0>;
> +
> +		flash@0 {
> +			compatible = "jedec,spi-nor";
> +			reg = <0>;
> +			spi-max-frequency = <40000000>;
> +			spi-tx-bus-width = <1>;
> +			spi-rx-bus-width = <1>;
> +		};
> +	};

[PATCH RFC 2/2] memory: add Renesas RPC-IF driver

[Sergei Shtylyov]

Add the memory driver for Renesas RPC-IF which registers either SPI or
HyperFLash device depending on the contents of the device tree subnode.
It also provides the absract "back end" device APIs that can be used by
the "front end" SPI/MTD drivers to talk to the real hardware.

Based on the original patch by Mason Yang <masonccyang@mxic.com.tw>.

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

---
 drivers/memory/Kconfig          |    9 
 drivers/memory/Makefile         |    1 
 drivers/memory/renesas-rpc-if.c |  590 ++++++++++++++++++++++++++++++++++++++++
 include/memory/renesas-rpc-if.h |   87 +++++
 4 files changed, 687 insertions(+)

Index: linux/drivers/memory/Kconfig
===================================================================
--- linux.orig/drivers/memory/Kconfig
+++ linux/drivers/memory/Kconfig
@@ -163,6 +163,15 @@ config PL353_SMC
 	  This driver is for the ARM PL351/PL353 Static Memory
 	  Controller(SMC) module.
 
+config RENESAS_RPCIF
+	tristate "Renesas RPC-IF driver"
+	depends on ARCH_RENESAS
+	select REGMAP_MMIO
+	help
+	  This supports Renesas R-Car Gen3 RPC-IF which provides either SPI
+	  host or HyperFlash. You'll have to select individual components
+	  under the corresponding menu.
+
 source "drivers/memory/samsung/Kconfig"
 source "drivers/memory/tegra/Kconfig"
 
Index: linux/drivers/memory/Makefile
===================================================================
--- linux.orig/drivers/memory/Makefile
+++ linux/drivers/memory/Makefile
@@ -21,6 +21,7 @@ obj-$(CONFIG_JZ4780_NEMC)	+= jz4780-nemc
 obj-$(CONFIG_MTK_SMI)		+= mtk-smi.o
 obj-$(CONFIG_DA8XX_DDRCTL)	+= da8xx-ddrctl.o
 obj-$(CONFIG_PL353_SMC)		+= pl353-smc.o
+obj-$(CONFIG_RENESAS_RPCIF)	+= renesas-rpc-if.o
 
 obj-$(CONFIG_SAMSUNG_MC)	+= samsung/
 obj-$(CONFIG_TEGRA_MC)		+= tegra/
Index: linux/drivers/memory/renesas-rpc-if.c
===================================================================
--- /dev/null
+++ linux/drivers/memory/renesas-rpc-if.c
@@ -0,0 +1,590 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Renesas RPC-IF driver
+ *
+ * Copyright (C) 2018 ~ 2019 Renesas Solutions Corp.
+ * Copyright (C) 2019 Macronix International Co., Ltd.
+ * Copyright (C) 2019 Cogent Embedded, Inc.
+ */
+
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/of.h>
+#include <linux/pm_runtime.h>
+#include <linux/regmap.h>
+#include <linux/reset.h>
+
+#include <memory/renesas-rpc-if.h>
+
+#define RPCIF_CMNCR		0x0000	/* R/W */
+#define RPCIF_CMNCR_MD		BIT(31)
+#define RPCIF_CMNCR_SFDE	BIT(24) /* undocumented but must be set */
+#define RPCIF_CMNCR_MOIIO3(val)	(((val) & 0x3) << 22)
+#define RPCIF_CMNCR_MOIIO2(val)	(((val) & 0x3) << 20)
+#define RPCIF_CMNCR_MOIIO1(val)	(((val) & 0x3) << 18)
+#define RPCIF_CMNCR_MOIIO0(val)	(((val) & 0x3) << 16)
+#define RPCIF_CMNCR_MOIIO_HIZ	(RPCIF_CMNCR_MOIIO0(3) | \
+				 RPCIF_CMNCR_MOIIO1(3) | \
+				 RPCIF_CMNCR_MOIIO2(3) | RPCIF_CMNCR_MOIIO3(3))
+#define RPCIF_CMNCR_IO3FV(val)	(((val) & 0x3) << 14) /* undocumented */
+#define RPCIF_CMNCR_IO2FV(val)	(((val) & 0x3) << 12) /* undocumented */
+#define RPCIF_CMNCR_IO0FV(val)	(((val) & 0x3) << 8)
+#define RPCIF_CMNCR_IOFV_HIZ	(RPCIF_CMNCR_IO0FV(3) | RPCIF_CMNCR_IO2FV(3) | \
+				 RPCIF_CMNCR_IO3FV(3))
+#define RPCIF_CMNCR_BSZ(val)	(((val) & 0x3) << 0)
+
+#define RPCIF_SSLDR		0x0004	/* R/W */
+#define RPCIF_SSLDR_SPNDL(d)	(((d) & 0x7) << 16)
+#define RPCIF_SSLDR_SLNDL(d)	(((d) & 0x7) << 8)
+#define RPCIF_SSLDR_SCKDL(d)	(((d) & 0x7) << 0)
+
+#define RPCIF_DRCR		0x000C	/* R/W */
+#define RPCIF_DRCR_SSLN		BIT(24)
+#define RPCIF_DRCR_RBURST(v)	((((v) - 1) & 0x1F) << 16)
+#define RPCIF_DRCR_RCF		BIT(9)
+#define RPCIF_DRCR_RBE		BIT(8)
+#define RPCIF_DRCR_SSLE		BIT(0)
+
+#define RPCIF_DRCMR		0x0010	/* R/W */
+#define RPCIF_DRCMR_CMD(c)	(((c) & 0xFF) << 16)
+#define RPCIF_DRCMR_OCMD(c)	(((c) & 0xFF) << 0)
+
+#define RPCIF_DREAR		0x0014	/* R/W */
+#define RPCIF_DREAR_EAV(c)	(((c) & 0xf) << 16)
+#define RPCIF_DREAR_EAC(c)	(((c) & 0x7) << 0)
+
+#define RPCIF_DROPR		0x0018	/* R/W */
+
+#define RPCIF_DRENR		0x001C	/* R/W */
+#define RPCIF_DRENR_CDB(o)	(u32)((((o) & 0x3) << 30))
+#define RPCIF_DRENR_OCDB(o)	(((o) & 0x3) << 28)
+#define RPCIF_DRENR_ADB(o)	(((o) & 0x3) << 24)
+#define RPCIF_DRENR_OPDB(o)	(((o) & 0x3) << 20)
+#define RPCIF_DRENR_DRDB(o)	(((o) & 0x3) << 16)
+#define RPCIF_DRENR_DME		BIT(15)
+#define RPCIF_DRENR_CDE		BIT(14)
+#define RPCIF_DRENR_OCDE	BIT(12)
+#define RPCIF_DRENR_ADE(v)	(((v) & 0xF) << 8)
+#define RPCIF_DRENR_OPDE(v)	(((v) & 0xF) << 4)
+
+#define RPCIF_SMCR		0x0020	/* R/W */
+#define RPCIF_SMCR_SSLKP	BIT(8)
+#define RPCIF_SMCR_SPIRE	BIT(2)
+#define RPCIF_SMCR_SPIWE	BIT(1)
+#define RPCIF_SMCR_SPIE		BIT(0)
+
+#define RPCIF_SMCMR		0x0024	/* R/W */
+#define RPCIF_SMCMR_CMD(c)	(((c) & 0xFF) << 16)
+#define RPCIF_SMCMR_OCMD(c)	(((c) & 0xFF) << 0)
+
+#define RPCIF_SMADR		0x0028	/* R/W */
+
+#define RPCIF_SMOPR		0x002C	/* R/W */
+#define RPCIF_SMOPR_OPD3(o)	(((o) & 0xFF) << 24)
+#define RPCIF_SMOPR_OPD2(o)	(((o) & 0xFF) << 16)
+#define RPCIF_SMOPR_OPD1(o)	(((o) & 0xFF) << 8)
+#define RPCIF_SMOPR_OPD0(o)	(((o) & 0xFF) << 0)
+
+#define RPCIF_SMENR		0x0030	/* R/W */
+#define RPCIF_SMENR_CDB(o)	(((o) & 0x3) << 30)
+#define RPCIF_SMENR_OCDB(o)	(((o) & 0x3) << 28)
+#define RPCIF_SMENR_ADB(o)	(((o) & 0x3) << 24)
+#define RPCIF_SMENR_OPDB(o)	(((o) & 0x3) << 20)
+#define RPCIF_SMENR_SPIDB(o)	(((o) & 0x3) << 16)
+#define RPCIF_SMENR_DME		BIT(15)
+#define RPCIF_SMENR_CDE		BIT(14)
+#define RPCIF_SMENR_OCDE	BIT(12)
+#define RPCIF_SMENR_ADE(v)	(((v) & 0xF) << 8)
+#define RPCIF_SMENR_OPDE(v)	(((v) & 0xF) << 4)
+#define RPCIF_SMENR_SPIDE(v)	(((v) & 0xF) << 0)
+
+#define RPCIF_SMRDR0		0x0038	/* R */
+#define RPCIF_SMRDR1		0x003C	/* R */
+#define RPCIF_SMWDR0		0x0040	/* W */
+#define RPCIF_SMWDR1		0x0044	/* W */
+
+#define RPCIF_CMNSR		0x0048	/* R */
+#define RPCIF_CMNSR_SSLF	BIT(1)
+#define RPCIF_CMNSR_TEND	BIT(0)
+
+#define RPCIF_DRDMCR		0x0058	/* R/W */
+#define RPCIF_DMDMCR_DMCYC(v)	((((v) - 1) & 0x1F) << 0)
+
+#define RPCIF_DRDRENR		0x005C	/* R/W */
+#define RPCIF_DRDRENR_HYPE(v)	(((v) & 0x7) << 12)
+#define RPCIF_DRDRENR_ADDRE	BIT(8)
+#define RPCIF_DRDRENR_OPDRE	BIT(4)
+#define RPCIF_DRDRENR_DRDRE	BIT(0)
+
+#define RPCIF_SMDMCR		0x0060	/* R/W */
+#define RPCIF_SMDMCR_DMCYC(v)	((((v) - 1) & 0x1F) << 0)
+
+#define RPCIF_SMDRENR		0x0064	/* R/W */
+#define RPCIF_SMDRENR_HYPE(v)	(((v) & 0x7) << 12)
+#define RPCIF_SMDRENR_ADDRE	BIT(8)
+#define RPCIF_SMDRENR_OPDRE	BIT(4)
+#define RPCIF_SMDRENR_SPIDRE	BIT(0)
+
+#define RPCIF_PHYCNT		0x007C	/* R/W */
+#define RPCIF_PHYCNT_CAL	BIT(31)
+#define RPCIF_PHYCNT_OCTA_AA	BIT(22)
+#define RPCIF_PHYCNT_OCTA_SA	BIT(23)
+#define RPCIF_PHYCNT_EXDS	BIT(21)
+#define RPCIF_PHYCNT_OCT	BIT(20)
+#define RPCIF_PHYCNT_STRTIM(v)	(((v) & 0x7) << 15)
+#define RPCIF_PHYCNT_WBUF2	BIT(4)
+#define RPCIF_PHYCNT_WBUF	BIT(2)
+#define RPCIF_PHYCNT_PHYMEM(v)	(((v) & 0x3) << 0)
+
+#define RPCIF_PHYOFFSET1	0x0080	/* R/W */
+#define RPCIF_PHYOFFSET1_DDRTMG(v) (((v) & 0x3) << 28)
+
+#define RPCIF_PHYOFFSET2	0x0084	/* R/W */
+#define RPCIF_PHYOFFSET2_OCTTMG(v) (((v) & 0x7) << 8)
+
+#define RPCIF_PHYINT		0x0088	/* R/W */
+#define RPCIF_PHYINT_WPVAL	BIT(1)
+
+#define RPCIF_DIRMAP_SIZE	0x4000000
+
+static const struct regmap_range rpcif_volatile_ranges[] = {
+	regmap_reg_range(RPCIF_SMRDR0, RPCIF_SMRDR1),
+	regmap_reg_range(RPCIF_SMWDR0, RPCIF_SMWDR1),
+	regmap_reg_range(RPCIF_CMNSR, RPCIF_CMNSR),
+};
+
+static const struct regmap_access_table rpcif_volatile_table = {
+	.yes_ranges	= rpcif_volatile_ranges,
+	.n_yes_ranges	= ARRAY_SIZE(rpcif_volatile_ranges),
+};
+
+static const struct regmap_config rpcif_regmap_config = {
+	.reg_bits	= 32,
+	.val_bits	= 32,
+	.reg_stride	= 4,
+	.fast_io	= true,
+	.max_register	= RPCIF_PHYINT,
+	.volatile_table	= &rpcif_volatile_table,
+};
+
+int rpcif_sw_init(struct rpcif *rpc, struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct resource *res;
+	void __iomem *base;
+
+	rpc->dev = dev;
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "regs");
+	base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	rpc->regmap = devm_regmap_init_mmio(&pdev->dev, base,
+					    &rpcif_regmap_config);
+	if (IS_ERR(rpc->regmap)) {
+		dev_err(&pdev->dev,
+			"failed to init regmap for rpcif, error %ld\n",
+			PTR_ERR(rpc->regmap));
+		return	PTR_ERR(rpc->regmap);
+	}
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dirmap");
+	rpc->size = resource_size(res);
+	rpc->dirmap = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(rpc->dirmap))
+		rpc->dirmap = NULL;
+
+	rpc->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL);
+	if (IS_ERR(rpc->rstc))
+		return PTR_ERR(rpc->rstc);
+
+	return 0;
+}
+EXPORT_SYMBOL(rpcif_sw_init);
+
+void rpcif_enable_rpm(struct rpcif *rpc)
+{
+	pm_runtime_enable(rpc->dev);
+}
+EXPORT_SYMBOL(rpcif_enable_rpm);
+
+void rpcif_disable_rpm(struct rpcif *rpc)
+{
+	pm_runtime_put_sync(rpc->dev);
+}
+EXPORT_SYMBOL(rpcif_disable_rpm);
+
+void rpcif_hw_init(struct rpcif *rpc, bool hyperflash)
+{
+	pm_runtime_get_sync(rpc->dev);
+
+	/*
+	 * NOTE: The 0x260 are undocumented bits, but they must be set.
+	 *	 RPCIF_PHYCNT_STRTIM is strobe timing adjustment bits,
+	 *	 0x0 : the delay is biggest,
+	 *	 0x1 : the delay is 2nd biggest,
+	 *	 On H3 ES1.x, the value should be 0, while on others,
+	 *	 the value should be 6.
+	 */
+	regmap_write(rpc->regmap, RPCIF_PHYCNT, /* RPCIF_PHYCNT_STRTIM(6) | */
+		     RPCIF_PHYCNT_PHYMEM(hyperflash ? 3 : 0) | 0x260);
+
+	/*
+	 * NOTE: The 0x1511144 are undocumented bits, but they must be set
+	 *       for RPCIF_PHYOFFSET1.
+	 *	 The 0x31 are undocumented bits, but they must be set
+	 *	 for RPCIF_PHYOFFSET2.
+	 */
+	regmap_write(rpc->regmap, RPCIF_PHYOFFSET1, 0x1511144 |
+		     RPCIF_PHYOFFSET1_DDRTMG(3));
+	regmap_write(rpc->regmap, RPCIF_PHYOFFSET2, 0x31 |
+		     RPCIF_PHYOFFSET2_OCTTMG(4));
+
+	if (hyperflash)
+		regmap_update_bits(rpc->regmap, RPCIF_PHYINT,
+				   RPCIF_PHYINT_WPVAL, 0);
+
+	regmap_write(rpc->regmap, RPCIF_CMNCR, RPCIF_CMNCR_SFDE |
+		     RPCIF_CMNCR_MOIIO_HIZ | RPCIF_CMNCR_IOFV_HIZ |
+		     RPCIF_CMNCR_BSZ(hyperflash ? 1 : 0));
+	regmap_write(rpc->regmap, RPCIF_SSLDR, RPCIF_SSLDR_SPNDL(7) |
+		     RPCIF_SSLDR_SLNDL(7) | RPCIF_SSLDR_SCKDL(7));
+
+	pm_runtime_put(rpc->dev);
+
+	rpc->bus_size = hyperflash ? 2 : 1;
+}
+EXPORT_SYMBOL(rpcif_hw_init);
+
+static int wait_msg_xfer_end(struct rpcif *rpc)
+{
+	u32 sts;
+
+	return regmap_read_poll_timeout(rpc->regmap, RPCIF_CMNSR, sts,
+					sts & RPCIF_CMNSR_TEND, 0,
+					USEC_PER_SEC);
+}
+
+static u8 rpcif_bits_set(struct rpcif *rpc, u32 nbytes)
+{
+	if (rpc->bus_size == 2)
+		nbytes /= 2;
+	nbytes = clamp(nbytes, 1U, 4U);
+	return GENMASK(3, 4 - nbytes);
+}
+
+static u8 rpcif_bit_size(u8 buswidth)
+{
+	return buswidth > 4 ? 2 : ilog2(buswidth);
+}
+
+void rpcif_prepare(struct rpcif *rpc, const struct rpcif_op *op, u64 *offs,
+		   size_t *len)
+{
+	rpc->enable = 0;
+	rpc->command = 0;
+	rpc->smadr = 0;
+	rpc->ddr = 0;
+	rpc->xferlen = 0;
+
+	if (op->cmd.buswidth) {
+		rpc->enable  |= RPCIF_SMENR_CDE |
+			RPCIF_SMENR_CDB(rpcif_bit_size(op->cmd.buswidth));
+		rpc->command |= RPCIF_SMCMR_CMD(op->cmd.opcode);
+		if (op->cmd.ddr)
+			rpc->ddr |= RPCIF_SMDRENR_HYPE(0x5);
+	}
+	if (op->ocmd.buswidth) {
+		rpc->enable  |= RPCIF_SMENR_OCDE |
+			RPCIF_SMENR_OCDB(rpcif_bit_size(op->ocmd.buswidth));
+		rpc->command |= RPCIF_SMCMR_OCMD(op->ocmd.opcode);
+	}
+
+	if (op->addr.buswidth) {
+		rpc->enable |=
+			RPCIF_SMENR_ADB(rpcif_bit_size(op->addr.buswidth));
+		if (op->addr.nbytes == 4)
+			rpc->enable |= RPCIF_SMENR_ADE(0xf);
+		else
+			rpc->enable |= RPCIF_SMENR_ADE(GENMASK(
+						2, 3 - op->addr.nbytes));
+		if (op->addr.ddr)
+			rpc->ddr |= RPCIF_SMDRENR_ADDRE;
+
+		if (offs && len)
+			rpc->smadr = *offs;
+		else
+			rpc->smadr = op->addr.val;
+	}
+
+	if (op->dummy.buswidth) {
+		rpc->enable |= RPCIF_SMENR_DME;
+		rpc->dummy = RPCIF_SMDMCR_DMCYC(op->dummy.ncycles /
+						op->dummy.buswidth);
+	}
+
+	if (op->option.buswidth) {
+		rpc->enable |= RPCIF_SMENR_OPDE(
+			rpcif_bits_set(rpc, op->option.nbytes)) |
+			RPCIF_SMENR_OPDB(rpcif_bit_size(op->option.buswidth));
+		if (op->option.ddr)
+			rpc->ddr |= RPCIF_SMDRENR_OPDRE;
+		rpc->option = op->option.val;
+	}
+
+	if (op->data.buswidth || (offs && len)) {
+		u32 nbytes;
+
+		rpc->dir = op->data.dir;
+		rpc->buffer = op->data.buf.in;
+		switch (op->data.dir) {
+		case RPCIF_DATA_IN:
+			rpc->smcr = RPCIF_SMCR_SPIRE;
+			break;
+		case RPCIF_DATA_OUT:
+			rpc->smcr = RPCIF_SMCR_SPIWE;
+			break;
+		default:
+			break;
+		}
+		if (op->data.ddr)
+			rpc->ddr |= RPCIF_SMDRENR_SPIDRE;
+
+		if (offs && len)
+			nbytes = *len;
+		else
+			nbytes = op->data.nbytes;
+		rpc->xferlen = nbytes;
+
+		rpc->enable |= RPCIF_SMENR_SPIDE(rpcif_bits_set(rpc, nbytes)) |
+			RPCIF_SMENR_SPIDB(rpcif_bit_size(op->data.buswidth));
+	}
+}
+EXPORT_SYMBOL(rpcif_prepare);
+
+int rpcif_io_xfer(struct rpcif *rpc)
+{
+	u32 smenr, smcr, pos = 0, max = 4;
+	int ret = 0;
+
+	pm_runtime_get_sync(rpc->dev);
+
+	if (rpc->bus_size == 2)
+		max = 8;
+
+	regmap_update_bits(rpc->regmap, RPCIF_PHYCNT,
+			   RPCIF_PHYCNT_CAL, RPCIF_PHYCNT_CAL);
+	regmap_update_bits(rpc->regmap, RPCIF_CMNCR,
+			   RPCIF_CMNCR_MD, RPCIF_CMNCR_MD);
+	regmap_write(rpc->regmap, RPCIF_SMCMR, rpc->command);
+	regmap_write(rpc->regmap, RPCIF_SMOPR, rpc->option);
+	regmap_write(rpc->regmap, RPCIF_SMDMCR, rpc->dummy);
+	regmap_write(rpc->regmap, RPCIF_SMDRENR, rpc->ddr);
+	smenr = rpc->enable;
+
+	switch (rpc->dir) {
+	case RPCIF_DATA_OUT:
+		while (pos < rpc->xferlen) {
+			u32 nbytes = rpc->xferlen - pos;
+			u32 data[2];
+
+			smcr = rpc->smcr | RPCIF_SMCR_SPIE;
+			if (nbytes > max) {
+				nbytes = max;
+				smcr |= RPCIF_SMCR_SSLKP;
+			}
+
+			memcpy(data, rpc->buffer + pos, nbytes);
+			if (nbytes > 4) {
+				regmap_write(rpc->regmap, RPCIF_SMWDR1,
+					     data[0]);
+				regmap_write(rpc->regmap, RPCIF_SMWDR0,
+					     data[1]);
+			} else if (nbytes > 2) {
+				regmap_write(rpc->regmap, RPCIF_SMWDR0,
+					     data[0]);
+			} else	{
+				regmap_write(rpc->regmap, RPCIF_SMWDR0,
+					     data[0] << 16);
+			}
+
+			regmap_write(rpc->regmap, RPCIF_SMADR,
+				     rpc->smadr + pos);
+			regmap_write(rpc->regmap, RPCIF_SMENR, smenr);
+			regmap_write(rpc->regmap, RPCIF_SMCR, smcr);
+			ret = wait_msg_xfer_end(rpc);
+			if (ret)
+				goto err_out;
+
+			pos += nbytes;
+			smenr = rpc->enable &
+				~RPCIF_SMENR_CDE & ~RPCIF_SMENR_ADE(0xf);
+		}
+		break;
+	case RPCIF_DATA_IN:
+		/*
+		 * RPC-IF spoils the data for the commands without an address
+		 * phase (like RDID) in the manual mode, so we'll have to work
+		 * around this issue by using the external address space read
+		 * mode instead.
+		 */
+		if (!(smenr & RPCIF_SMENR_ADE(0xf)) && rpc->dirmap) {
+			regmap_update_bits(rpc->regmap, RPCIF_CMNCR,
+					   RPCIF_CMNCR_MD, 0);
+			regmap_write(rpc->regmap, RPCIF_DRCR,
+				     RPCIF_DRCR_RBURST(32) | RPCIF_DRCR_RBE);
+			regmap_write(rpc->regmap, RPCIF_DRCMR, rpc->command);
+			regmap_write(rpc->regmap, RPCIF_DREAR,
+				     RPCIF_DREAR_EAC(1));
+			regmap_write(rpc->regmap, RPCIF_DROPR, rpc->option);
+			regmap_write(rpc->regmap, RPCIF_DRENR,
+				     smenr & ~RPCIF_SMENR_SPIDE(0xf));
+			regmap_write(rpc->regmap, RPCIF_DRDMCR,  rpc->dummy);
+			regmap_write(rpc->regmap, RPCIF_DRDRENR, rpc->ddr);
+			memcpy_fromio(rpc->buffer, rpc->dirmap, rpc->xferlen);
+			regmap_write(rpc->regmap, RPCIF_DRCR, RPCIF_DRCR_RCF);
+			break;
+		}
+		while (pos < rpc->xferlen) {
+			u32 nbytes = rpc->xferlen - pos;
+			u32 data[2];
+
+			if (nbytes > max)
+				nbytes = max;
+
+			regmap_write(rpc->regmap, RPCIF_SMADR,
+				     rpc->smadr + pos);
+			regmap_write(rpc->regmap, RPCIF_SMENR, smenr);
+			regmap_write(rpc->regmap, RPCIF_SMCR,
+					     rpc->smcr	| RPCIF_SMCR_SPIE);
+			ret = wait_msg_xfer_end(rpc);
+			if (ret)
+				goto err_out;
+
+			if (nbytes > 4) {
+				regmap_read(rpc->regmap, RPCIF_SMRDR1,
+					    &data[0]);
+				regmap_read(rpc->regmap, RPCIF_SMRDR0,
+					    &data[1]);
+			} else if (nbytes > 2) {
+				regmap_read(rpc->regmap, RPCIF_SMRDR0,
+					    &data[0]);
+			} else	{
+				regmap_read(rpc->regmap, RPCIF_SMRDR0,
+					    &data[0]);
+				data[0] >>= 16;
+			}
+			memcpy(rpc->buffer + pos, data, nbytes);
+
+			pos += nbytes;
+		}
+		break;
+	default:
+		regmap_write(rpc->regmap, RPCIF_SMENR, rpc->enable);
+		regmap_write(rpc->regmap, RPCIF_SMCR,
+			     rpc->smcr | RPCIF_SMCR_SPIE);
+		ret = wait_msg_xfer_end(rpc);
+		if (ret)
+			goto err_out;
+	}
+
+exit:
+	pm_runtime_put(rpc->dev);
+	return ret;
+
+err_out:
+	ret = reset_control_reset(rpc->rstc);
+	rpcif_hw_init(rpc, rpc->bus_size == 2);
+	goto exit;
+}
+EXPORT_SYMBOL(rpcif_io_xfer);
+
+ssize_t rpcif_dirmap_read(struct rpcif *rpc, u64 offs, size_t len, void *buf)
+{
+	loff_t from = offs & (RPCIF_DIRMAP_SIZE - 1);
+	size_t size = RPCIF_DIRMAP_SIZE - from;
+
+	if (len > size)
+		len = size;
+
+	pm_runtime_get_sync(rpc->dev);
+
+	regmap_update_bits(rpc->regmap, RPCIF_CMNCR, RPCIF_CMNCR_MD, 0);
+	regmap_write(rpc->regmap, RPCIF_DRCR,
+		     RPCIF_DRCR_RBURST(32) | RPCIF_DRCR_RBE);
+	regmap_write(rpc->regmap, RPCIF_DRCMR, rpc->command);
+	regmap_write(rpc->regmap, RPCIF_DREAR,
+		     RPCIF_DREAR_EAV(offs >> 25) | RPCIF_DREAR_EAC(1));
+	regmap_write(rpc->regmap, RPCIF_DROPR, rpc->option);
+	regmap_write(rpc->regmap, RPCIF_DRENR,
+		     rpc->enable & ~RPCIF_SMENR_SPIDE(0xF));
+	regmap_write(rpc->regmap, RPCIF_DRDMCR, rpc->dummy);
+	regmap_write(rpc->regmap, RPCIF_DRDRENR, rpc->ddr);
+
+	memcpy_fromio(buf, rpc->dirmap + from, len);
+
+	pm_runtime_put(rpc->dev);
+
+	return len;
+}
+EXPORT_SYMBOL(rpcif_dirmap_read);
+
+static int rpcif_probe(struct platform_device *pdev)
+{
+	struct platform_device *vdev;
+	struct device_node *flash;
+	const char *name;
+
+	flash = of_get_next_child(pdev->dev.of_node, NULL);
+	if (!flash) {
+		dev_warn(&pdev->dev, "no flash node found\n");
+		return -ENODEV;
+	}
+
+	if (of_device_is_compatible(flash, "jedec,spi-nor")) {
+		name = "rpc-if-spi";
+	} else if (of_device_is_compatible(flash, "cfi-flash")) {
+		name = "rpc-if-hyperflash";
+	} else {
+		dev_warn(&pdev->dev, "unknown flash type\n");
+		return -ENODEV;
+	}
+
+	vdev = platform_device_alloc(name, pdev->id);
+	if (!vdev)
+		return -ENOMEM;
+	vdev->dev.parent = &pdev->dev;
+	platform_set_drvdata(pdev, vdev);
+	return platform_device_add(vdev);
+}
+
+static int rpcif_remove(struct platform_device *pdev)
+{
+	struct platform_device *vdev = platform_get_drvdata(pdev);
+
+	platform_device_unregister(vdev);
+
+	return 0;
+}
+
+static const struct of_device_id rpcif_of_match[] = {
+	{ .compatible = "renesas,rcar-gen3-rpc-if", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, rpcif_of_match);
+
+static struct platform_driver rpcif_driver = {
+	.probe	= rpcif_probe,
+	.remove	= rpcif_remove,
+	.driver = {
+		.name =	"rpc-if",
+		.of_match_table = rpcif_of_match,
+	},
+};
+module_platform_driver(rpcif_driver);
+
+MODULE_DESCRIPTION("Renesas RPC-IF MFD driver");
+MODULE_LICENSE("GPL v2");
Index: linux/include/memory/renesas-rpc-if.h
===================================================================
--- /dev/null
+++ linux/include/memory/renesas-rpc-if.h
@@ -0,0 +1,87 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * R-Car Gen3 RPC-IF driver
+ *
+ * Copyright (C) 2018 ~ 2019 Renesas Solutions Corp.
+ * Copyright (C) 2019 Macronix International Co., Ltd.
+ * Copyright (C) 2019 Cogent Embedded, Inc.
+ */
+
+#ifndef __RENESAS_RPC_IF_H
+#define __RENESAS_RPC_IF_H
+
+#include <linux/types.h>
+
+enum rpcif_data_dir {
+	RPCIF_NO_DATA,
+	RPCIF_DATA_IN,
+	RPCIF_DATA_OUT,
+};
+
+struct	rpcif_op {
+	struct {
+		u8 buswidth;
+		u8 opcode;
+		bool ddr;
+	} cmd, ocmd;
+
+	struct {
+		u8 nbytes;
+		u8 buswidth;
+		bool ddr;
+		u64 val;
+	} addr;
+
+	struct {
+		u8 ncycles;
+		u8 buswidth;
+	} dummy;
+
+	struct {
+		u8 nbytes;
+		u8 buswidth;
+		bool ddr;
+		u32 val;
+	} option;
+
+	struct {
+		u8 buswidth;
+		unsigned int nbytes;
+		enum rpcif_data_dir dir;
+		bool ddr;
+		union {
+			void *in;
+			const void *out;
+		} buf;
+	} data;
+};
+
+struct	rpcif {
+	struct device *dev;
+	void __iomem *dirmap;
+	struct regmap *regmap;
+	struct reset_control *rstc;
+	size_t size;
+	enum rpcif_data_dir dir;
+	u8 bus_size;
+	void *buffer;
+	u32 xferlen;
+	u32 smcr;
+	u32 command;		/* DRCMR or SMCMR */
+	u32 smadr;
+	u32 option;		/* DROPR or SMOPR */
+	u32 enable;		/* DRENR or SMENR */
+	u32 dummy;		/* DRDMCR or SMDMCR */
+	u32 ddr;		/* DRDRENR or SMDRENR */
+};
+
+int  rpcif_sw_init(struct rpcif *rpc, struct device *dev);
+void rpcif_hw_init(struct rpcif *rpc, bool hyperflash);
+void rpcif_enable_rpm(struct rpcif *rpc);
+void rpcif_disable_rpm(struct rpcif *rpc);
+void rpcif_prepare(struct rpcif *rpc, const struct rpcif_op *op, u64 *offs,
+		   size_t *len);
+int rpcif_io_xfer(struct rpcif *rpc);
+ssize_t rpcif_dirmap_read(struct rpcif *rpc, u64 offs, size_t len, void *buf);
+
+#endif // __RENESAS_RPC_IF_H

Re: [PATCH RFC 2/2] memory: add Renesas RPC-IF driver

[Philipp Zabel]

Hi Sergei,

On Tue, 2019-12-10 at 22:39 +0300, Sergei Shtylyov wrote:
[...]
> --- /dev/null
> +++ linux/drivers/memory/renesas-rpc-if.c
> @@ -0,0 +1,590 @@
[...]
> +int rpcif_io_xfer(struct rpcif *rpc)
> +{
[...]
> +	default:
> +		regmap_write(rpc->regmap, RPCIF_SMENR, rpc->enable);
> +		regmap_write(rpc->regmap, RPCIF_SMCR,
> +			     rpc->smcr | RPCIF_SMCR_SPIE);
> +		ret = wait_msg_xfer_end(rpc);
> +		if (ret)
> +			goto err_out;
> +	}
> +
> +exit:
> +	pm_runtime_put(rpc->dev);
> +	return ret;
> +
> +err_out:
> +	ret = reset_control_reset(rpc->rstc);

If wait_msg_xfer_end() returned an error, but the reset succeeds, this
will cause rpcif_io_xfer() to report success as well. I suspect you do
not want to overwrite ret at this point.

> +	rpcif_hw_init(rpc, rpc->bus_size == 2);
> +	goto exit;
> +}
> +EXPORT_SYMBOL(rpcif_io_xfer);

regards
Philipp

Re: [PATCH RFC 2/2] memory: add Renesas RPC-IF driver

[Behme Dirk (CM/ESO2)]

Hi Sergei,

On 10.12.2019 20:39, Sergei Shtylyov wrote:
> Add the memory driver for Renesas RPC-IF which registers either SPI or
> HyperFLash device depending on the contents of the device tree subnode.
> It also provides the absract "back end" device APIs that can be used by
> the "front end" SPI/MTD drivers to talk to the real hardware.
> 
> Based on the original patch by Mason Yang <masonccyang@mxic.com.tw>.
> 
> Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>


FYI, please find below [1] the changes I did locally on this driver. It 
seems to read & write successfully on my custom M3 (R8A7796) device, now.

Best regards

Dirk

[1]

 From d72b805cc461ab1e9747c973e9be84e7abb8f828 Mon Sep 17 00:00:00 2001
From: Dirk Behme <dirk.behme@de.bosch.com>
Date: Tue, 4 Feb 2020 08:39:31 +0100
Subject: [PATCH] memory: renesas-rpc-if: Correct the STRTIM and some other
  clean up

This is required to make the driver work correctly in my M3 environment.

Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>
---
  drivers/memory/renesas-rpc-if.c | 42 ++++++++++++++++++++-------------
  1 file changed, 25 insertions(+), 17 deletions(-)

diff --git a/drivers/memory/renesas-rpc-if.c 
b/drivers/memory/renesas-rpc-if.c
index 04be92b64bfa..f4356b066384 100644
--- a/drivers/memory/renesas-rpc-if.c
+++ b/drivers/memory/renesas-rpc-if.c
@@ -129,10 +129,11 @@

  #define RPCIF_PHYCNT		0x007C	/* R/W */
  #define RPCIF_PHYCNT_CAL	BIT(31)
-#define RPCIF_PHYCNT_OCTA_AA	BIT(22)
-#define RPCIF_PHYCNT_OCTA_SA	BIT(23)
+#define RPCIF_PHYCNT_OCTA(v)	(((v) & 0x3) << 22)
  #define RPCIF_PHYCNT_EXDS	BIT(21)
  #define RPCIF_PHYCNT_OCT	BIT(20)
+#define RPCIF_PHYCNT_DDRCAL	BIT(19)
+#define RPCIF_PHYCNT_HS		BIT(18)
  #define RPCIF_PHYCNT_STRTIM(v)	(((v) & 0x7) << 15)
  #define RPCIF_PHYCNT_WBUF2	BIT(4)
  #define RPCIF_PHYCNT_WBUF	BIT(2)
@@ -219,6 +220,8 @@ EXPORT_SYMBOL(rpcif_disable_rpm);

  void rpcif_hw_init(struct rpcif *rpc, bool hyperflash)
  {
+	u32 dummy;
+
  	pm_runtime_get_sync(rpc->dev);

  	/*
@@ -227,9 +230,9 @@ void rpcif_hw_init(struct rpcif *rpc, bool hyperflash)
  	 *	 0x0 : the delay is biggest,
  	 *	 0x1 : the delay is 2nd biggest,
  	 *	 On H3 ES1.x, the value should be 0, while on others,
-	 *	 the value should be 6.
+	 *	 the value should be 7.
  	 */
-	regmap_write(rpc->regmap, RPCIF_PHYCNT, /* RPCIF_PHYCNT_STRTIM(6) | */
+	regmap_write(rpc->regmap, RPCIF_PHYCNT, RPCIF_PHYCNT_STRTIM(7) |
  		     RPCIF_PHYCNT_PHYMEM(hyperflash ? 3 : 0) | 0x260);

  	/*
@@ -250,6 +253,10 @@ void rpcif_hw_init(struct rpcif *rpc, bool hyperflash)
  	regmap_write(rpc->regmap, RPCIF_CMNCR, RPCIF_CMNCR_SFDE |
  		     RPCIF_CMNCR_MOIIO_HIZ | RPCIF_CMNCR_IOFV_HIZ |
  		     RPCIF_CMNCR_BSZ(hyperflash ? 1 : 0));
+	/* Set RCF after BSZ update */
+	regmap_write(rpc->regmap, RPCIF_DRCR, RPCIF_DRCR_RCF);
+	/* Dummy read according to spec */
+	regmap_read(rpc->regmap, RPCIF_DRCR, &dummy);
  	regmap_write(rpc->regmap, RPCIF_SSLDR, RPCIF_SSLDR_SPNDL(7) |
  		     RPCIF_SSLDR_SLNDL(7) | RPCIF_SSLDR_SCKDL(7));

@@ -291,11 +298,11 @@ void rpcif_prepare(struct rpcif *rpc, const struct 
rpcif_op *op, u64 *offs,
  	rpc->xferlen = 0;

  	if (op->cmd.buswidth) {
-		rpc->enable  |= RPCIF_SMENR_CDE |
+		rpc->enable  = RPCIF_SMENR_CDE |
  			RPCIF_SMENR_CDB(rpcif_bit_size(op->cmd.buswidth));
-		rpc->command |= RPCIF_SMCMR_CMD(op->cmd.opcode);
+		rpc->command = RPCIF_SMCMR_CMD(op->cmd.opcode);
  		if (op->cmd.ddr)
-			rpc->ddr |= RPCIF_SMDRENR_HYPE(0x5);
+			rpc->ddr = RPCIF_SMDRENR_HYPE(0x5);
  	}
  	if (op->ocmd.buswidth) {
  		rpc->enable  |= RPCIF_SMENR_OCDE |
@@ -432,6 +439,8 @@ int rpcif_io_xfer(struct rpcif *rpc)
  		 * mode instead.
  		 */
  		if (!(smenr & RPCIF_SMENR_ADE(0xf)) && rpc->dirmap) {
+			u32 dummy;
+
  			regmap_update_bits(rpc->regmap, RPCIF_CMNCR,
  					   RPCIF_CMNCR_MD, 0);
  			regmap_write(rpc->regmap, RPCIF_DRCR,
@@ -446,6 +455,8 @@ int rpcif_io_xfer(struct rpcif *rpc)
  			regmap_write(rpc->regmap, RPCIF_DRDRENR, rpc->ddr);
  			memcpy_fromio(rpc->buffer, rpc->dirmap, rpc->xferlen);
  			regmap_write(rpc->regmap, RPCIF_DRCR, RPCIF_DRCR_RCF);
+			/* Dummy read according to spec */
+			regmap_read(rpc->regmap, RPCIF_DRCR, &dummy);
  			break;
  		}
  		while (pos < rpc->xferlen) {
@@ -506,6 +517,7 @@ ssize_t rpcif_dirmap_read(struct rpcif *rpc, u64 
offs, size_t len, void *buf)
  {
  	loff_t from = offs & (RPCIF_DIRMAP_SIZE - 1);
  	size_t size = RPCIF_DIRMAP_SIZE - from;
+	u32 ret;

  	if (len > size)
  		len = size;
@@ -513,19 +525,15 @@ ssize_t rpcif_dirmap_read(struct rpcif *rpc, u64 
offs, size_t len, void *buf)
  	pm_runtime_get_sync(rpc->dev);

  	regmap_update_bits(rpc->regmap, RPCIF_CMNCR, RPCIF_CMNCR_MD, 0);
-	regmap_write(rpc->regmap, RPCIF_DRCR,
-		     RPCIF_DRCR_RBURST(32) | RPCIF_DRCR_RBE);
-	regmap_write(rpc->regmap, RPCIF_DRCMR, rpc->command);
-	regmap_write(rpc->regmap, RPCIF_DREAR,
-		     RPCIF_DREAR_EAV(offs >> 25) | RPCIF_DREAR_EAC(1));
-	regmap_write(rpc->regmap, RPCIF_DROPR, rpc->option);
-	regmap_write(rpc->regmap, RPCIF_DRENR,
-		     rpc->enable & ~RPCIF_SMENR_SPIDE(0xF));
-	regmap_write(rpc->regmap, RPCIF_DRDMCR, rpc->dummy);
-	regmap_write(rpc->regmap, RPCIF_DRDRENR, rpc->ddr);
+	ret = wait_msg_xfer_end(rpc);
+	if (ret) {
+		len = 0;
+		goto err_out;
+	}

  	memcpy_fromio(buf, rpc->dirmap + from, len);

+err_out:
  	pm_runtime_put(rpc->dev);

  	return len;
-- 
2.20.0

Re: [PATCH RFC 2/2] memory: add Renesas RPC-IF driver

[Sergei Shtylyov]

On 02/10/2020 01:21 PM, Behme Dirk (CM/ESO2) wrote:

>> Add the memory driver for Renesas RPC-IF which registers either SPI or
>> HyperFLash device depending on the contents of the device tree subnode.
>> It also provides the absract "back end" device APIs that can be used by
>> the "front end" SPI/MTD drivers to talk to the real hardware.
>>
>> Based on the original patch by Mason Yang <masonccyang-I/i+R0kf0WFNUHwG+Fw1Kw@public.gmane.org>.
>>
>> Signed-off-by: Sergei Shtylyov <sergei.shtylyov-M4DtvfQ/ZS1MRgGoP+s0PdBPR1lH4CV8@public.gmane.org>
> 
> 
> FYI, please find below [1] the changes I did locally on this driver. It seems to read & write successfully on my custom M3 (R8A7796) device, now.

   Not for me...
   BTW, your patch had whitespace ruined, I had to apply it by hand, you'd better
attach the patches, not paste. :-/

> Best regards
> 
> Dirk
> 
> [1]
> 
> From d72b805cc461ab1e9747c973e9be84e7abb8f828 Mon Sep 17 00:00:00 2001
> From: Dirk Behme <dirk.behme-V5te9oGctAVWk0Htik3J/w@public.gmane.org>
> Date: Tue, 4 Feb 2020 08:39:31 +0100
> Subject: [PATCH] memory: renesas-rpc-if: Correct the STRTIM and some other
>  clean up
> 
> This is required to make the driver work correctly in my M3 environment.
> 
> Signed-off-by: Dirk Behme <dirk.behme-V5te9oGctAVWk0Htik3J/w@public.gmane.org>
> ---
>  drivers/memory/renesas-rpc-if.c | 42 ++++++++++++++++++++-------------
>  1 file changed, 25 insertions(+), 17 deletions(-)
> 
> diff --git a/drivers/memory/renesas-rpc-if.c b/drivers/memory/renesas-rpc-if.c
> index 04be92b64bfa..f4356b066384 100644
> --- a/drivers/memory/renesas-rpc-if.c
> +++ b/drivers/memory/renesas-rpc-if.c
[...]
> @@ -513,19 +525,15 @@ ssize_t rpcif_dirmap_read(struct rpcif *rpc, u64 offs, size_t len, void *buf)
>      pm_runtime_get_sync(rpc->dev);
> 
>      regmap_update_bits(rpc->regmap, RPCIF_CMNCR, RPCIF_CMNCR_MD, 0);
> -    regmap_write(rpc->regmap, RPCIF_DRCR,
> -             RPCIF_DRCR_RBURST(32) | RPCIF_DRCR_RBE);
> -    regmap_write(rpc->regmap, RPCIF_DRCMR, rpc->command);
> -    regmap_write(rpc->regmap, RPCIF_DREAR,
> -             RPCIF_DREAR_EAV(offs >> 25) | RPCIF_DREAR_EAC(1));
> -    regmap_write(rpc->regmap, RPCIF_DROPR, rpc->option);
> -    regmap_write(rpc->regmap, RPCIF_DRENR,
> -             rpc->enable & ~RPCIF_SMENR_SPIDE(0xF));
> -    regmap_write(rpc->regmap, RPCIF_DRDMCR, rpc->dummy);
> -    regmap_write(rpc->regmap, RPCIF_DRDRENR, rpc->ddr);

   The driver somehow works only with this left in place (with 2 bytes eaten
as before), otherwise all the flash reads all 0xff (via dirmap).

> +    ret = wait_msg_xfer_end(rpc);
> +    if (ret) {
> +        len = 0;
> +        goto err_out;
> +    }
> 
>      memcpy_fromio(buf, rpc->dirmap + from, len);
> 
> +err_out:
>      pm_runtime_put(rpc->dev);
> 
>      return len;

MBR, Sergei

Re: [PATCH RFC 2/2] memory: add Renesas RPC-IF driver

[Behme Dirk (CM/ESO2)]

On 22.02.2020 21:42, Sergei Shtylyov wrote:
> On 02/10/2020 01:21 PM, Behme Dirk (CM/ESO2) wrote:
> 
>>> Add the memory driver for Renesas RPC-IF which registers either SPI or
>>> HyperFLash device depending on the contents of the device tree subnode.
>>> It also provides the absract "back end" device APIs that can be used by
>>> the "front end" SPI/MTD drivers to talk to the real hardware.
>>>
>>> Based on the original patch by Mason Yang <masonccyang-I/i+R0kf0WFNUHwG+Fw1Kw@public.gmane.org>.
>>>
>>> Signed-off-by: Sergei Shtylyov <sergei.shtylyov-M4DtvfQ/ZS1MRgGoP+s0PdBPR1lH4CV8@public.gmane.org>
>>
>>
>> FYI, please find below [1] the changes I did locally on this driver. It seems to read & write successfully on my custom M3 (R8A7796) device, now.
> 
>     Not for me...
>     BTW, your patch had whitespace ruined, I had to apply it by hand, you'd better
> attach the patches, not paste. :-/


Ok. There are other mailing lists complaining about attachments ;)

Even better, maybe we should put what we have so far publicly anywhere, 
e.g. github.


>> Best regards
>>
>> Dirk
>>
>> [1]
>>
>>  From d72b805cc461ab1e9747c973e9be84e7abb8f828 Mon Sep 17 00:00:00 2001
>> From: Dirk Behme <dirk.behme-V5te9oGctAVWk0Htik3J/w@public.gmane.org>
>> Date: Tue, 4 Feb 2020 08:39:31 +0100
>> Subject: [PATCH] memory: renesas-rpc-if: Correct the STRTIM and some other
>>   clean up
>>
>> This is required to make the driver work correctly in my M3 environment.
>>
>> Signed-off-by: Dirk Behme <dirk.behme-V5te9oGctAVWk0Htik3J/w@public.gmane.org>
>> ---
>>   drivers/memory/renesas-rpc-if.c | 42 ++++++++++++++++++++-------------
>>   1 file changed, 25 insertions(+), 17 deletions(-)
>>
>> diff --git a/drivers/memory/renesas-rpc-if.c b/drivers/memory/renesas-rpc-if.c
>> index 04be92b64bfa..f4356b066384 100644
>> --- a/drivers/memory/renesas-rpc-if.c
>> +++ b/drivers/memory/renesas-rpc-if.c
> [...]
>> @@ -513,19 +525,15 @@ ssize_t rpcif_dirmap_read(struct rpcif *rpc, u64 offs, size_t len, void *buf)
>>       pm_runtime_get_sync(rpc->dev);
>>
>>       regmap_update_bits(rpc->regmap, RPCIF_CMNCR, RPCIF_CMNCR_MD, 0);
>> -    regmap_write(rpc->regmap, RPCIF_DRCR,
>> -             RPCIF_DRCR_RBURST(32) | RPCIF_DRCR_RBE);
>> -    regmap_write(rpc->regmap, RPCIF_DRCMR, rpc->command);
>> -    regmap_write(rpc->regmap, RPCIF_DREAR,
>> -             RPCIF_DREAR_EAV(offs >> 25) | RPCIF_DREAR_EAC(1));
>> -    regmap_write(rpc->regmap, RPCIF_DROPR, rpc->option);
>> -    regmap_write(rpc->regmap, RPCIF_DRENR,
>> -             rpc->enable & ~RPCIF_SMENR_SPIDE(0xF));
>> -    regmap_write(rpc->regmap, RPCIF_DRDMCR, rpc->dummy);
>> -    regmap_write(rpc->regmap, RPCIF_DRDRENR, rpc->ddr);
> 
>     The driver somehow works only with this left in place (with 2 bytes eaten
> as before), otherwise all the flash reads all 0xff (via dirmap).


Do you boot from hyperflash?

The system I'm using for testing boots from hyperflash. So most probably 
all registers I don't touch in the driver are put into a reasonable 
state by the boot code, already. If you don't boot from hyperflash, that 
at least would explain our different behavior.

Best regards

Dirk

RE: [PATCH RFC 2/2] memory: add Renesas RPC-IF driver

[Chris Brandt]

On Mon, Feb 24, 2020 1, Behme Dirk (CM/ESO2) wrote:
> >     BTW, your patch had whitespace ruined, I had to apply it by hand, you'd
> better
> > attach the patches, not paste. :-/
> 
> 
> Ok. There are other mailing lists complaining about attachments ;)
> 
> Even better, maybe we should put what we have so far publicly anywhere,
> e.g. github.

That would be good for me as well since I'm also trying to make sure the
SPI mode works with the RZ/A devices, and I've already pointed out some
changes that are needed in the code for that.

Chris

Re: [PATCH RFC 2/2] memory: add Renesas RPC-IF driver

[Sergei Shtylyov]

Hello!

On 02/24/2020 08:46 AM, Behme Dirk (CM/ESO2) wrote:

>>>> Add the memory driver for Renesas RPC-IF which registers either SPI or
>>>> HyperFLash device depending on the contents of the device tree subnode.
>>>> It also provides the absract "back end" device APIs that can be used by
>>>> the "front end" SPI/MTD drivers to talk to the real hardware.
>>>>
>>>> Based on the original patch by Mason Yang <masonccyang@mxic.com.tw>.
>>>>
>>>> Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
>>>
>>>
>>> FYI, please find below [1] the changes I did locally on this driver. It seems to read & write successfully on my custom M3 (R8A7796) device, now.
>>
>>     Not for me...
>>     BTW, your patch had whitespace ruined, I had to apply it by hand, you'd better
>> attach the patches, not paste. :-/
> 
> 
> Ok. There are other mailing lists complaining about attachments ;)

   All Linux MLs prefer patches inline. :-)
   But you seem to paste the patches to the mail edited in some MUA (which does ruin
whitespace). Don't do that, it's better to just attach.

> Even better, maybe we should put what we have so far publicly anywhere, e.g. github.

  Cogent has an accout there, I'll try asking the management if it could also be used...

>>> Best regards
>>>
>>> Dirk
>>>
>>> [1]
>>>
>>>  From d72b805cc461ab1e9747c973e9be84e7abb8f828 Mon Sep 17 00:00:00 2001
>>> From: Dirk Behme <dirk.behme@de.bosch.com>
>>> Date: Tue, 4 Feb 2020 08:39:31 +0100
>>> Subject: [PATCH] memory: renesas-rpc-if: Correct the STRTIM and some other
>>>   clean up
>>>
>>> This is required to make the driver work correctly in my M3 environment.
>>>
>>> Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>
>>> ---
>>>   drivers/memory/renesas-rpc-if.c | 42 ++++++++++++++++++++-------------
>>>   1 file changed, 25 insertions(+), 17 deletions(-)
>>>
>>> diff --git a/drivers/memory/renesas-rpc-if.c b/drivers/memory/renesas-rpc-if.c
>>> index 04be92b64bfa..f4356b066384 100644
>>> --- a/drivers/memory/renesas-rpc-if.c
>>> +++ b/drivers/memory/renesas-rpc-if.c
>> [...]
>>> @@ -513,19 +525,15 @@ ssize_t rpcif_dirmap_read(struct rpcif *rpc, u64 offs, size_t len, void *buf)
>>>       pm_runtime_get_sync(rpc->dev);
>>>
>>>       regmap_update_bits(rpc->regmap, RPCIF_CMNCR, RPCIF_CMNCR_MD, 0);
>>> -    regmap_write(rpc->regmap, RPCIF_DRCR,
>>> -             RPCIF_DRCR_RBURST(32) | RPCIF_DRCR_RBE);
>>> -    regmap_write(rpc->regmap, RPCIF_DRCMR, rpc->command);
>>> -    regmap_write(rpc->regmap, RPCIF_DREAR,
>>> -             RPCIF_DREAR_EAV(offs >> 25) | RPCIF_DREAR_EAC(1));
>>> -    regmap_write(rpc->regmap, RPCIF_DROPR, rpc->option);
>>> -    regmap_write(rpc->regmap, RPCIF_DRENR,
>>> -             rpc->enable & ~RPCIF_SMENR_SPIDE(0xF));
>>> -    regmap_write(rpc->regmap, RPCIF_DRDMCR, rpc->dummy);
>>> -    regmap_write(rpc->regmap, RPCIF_DRDRENR, rpc->ddr);
>>
>>     The driver somehow works only with this left in place (with 2 bytes eaten
>> as before), otherwise all the flash reads all 0xff (via dirmap).
> 
> 
> Do you boot from hyperflash?

   No, I have arewto say 'cpld write 30 1' in U-Boot before a boot a kernel.
Normally, the V3x Starter Kit boards are wired for the QSPI flash chips.

> The system I'm using for testing boots from hyperflash. So most probably all registers
> I don't touch in the driver are put into a reasonable state by the boot code, already.
> If you don't boot from hyperflash, that at least would explain our different behavior.

   Yes. Mind dumping the registers and sending to me?

> Best regards
> 
> Dirk

MBR, Sergei

Re: [PATCH RFC 2/2] memory: add Renesas RPC-IF driver

[Behme Dirk (CM/ESO2)]

[-- Attachment #1: Type: text/plain, Size: 3427 bytes --]

On 24.02.2020 19:59, Sergei Shtylyov wrote:
>>>>   From d72b805cc461ab1e9747c973e9be84e7abb8f828 Mon Sep 17 00:00:00 2001
>>>> From: Dirk Behme <dirk.behme@de.bosch.com>
>>>> Date: Tue, 4 Feb 2020 08:39:31 +0100
>>>> Subject: [PATCH] memory: renesas-rpc-if: Correct the STRTIM and some other
>>>>    clean up
>>>>
>>>> This is required to make the driver work correctly in my M3 environment.
>>>>
>>>> Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>
>>>> ---
>>>>    drivers/memory/renesas-rpc-if.c | 42 ++++++++++++++++++++-------------
>>>>    1 file changed, 25 insertions(+), 17 deletions(-)
>>>>
>>>> diff --git a/drivers/memory/renesas-rpc-if.c b/drivers/memory/renesas-rpc-if.c
>>>> index 04be92b64bfa..f4356b066384 100644
>>>> --- a/drivers/memory/renesas-rpc-if.c
>>>> +++ b/drivers/memory/renesas-rpc-if.c
>>> [...]
>>>> @@ -513,19 +525,15 @@ ssize_t rpcif_dirmap_read(struct rpcif *rpc, u64 offs, size_t len, void *buf)
>>>>        pm_runtime_get_sync(rpc->dev);
>>>>
>>>>        regmap_update_bits(rpc->regmap, RPCIF_CMNCR, RPCIF_CMNCR_MD, 0);
>>>> -    regmap_write(rpc->regmap, RPCIF_DRCR,
>>>> -             RPCIF_DRCR_RBURST(32) | RPCIF_DRCR_RBE);
>>>> -    regmap_write(rpc->regmap, RPCIF_DRCMR, rpc->command);
>>>> -    regmap_write(rpc->regmap, RPCIF_DREAR,
>>>> -             RPCIF_DREAR_EAV(offs >> 25) | RPCIF_DREAR_EAC(1));
>>>> -    regmap_write(rpc->regmap, RPCIF_DROPR, rpc->option);
>>>> -    regmap_write(rpc->regmap, RPCIF_DRENR,
>>>> -             rpc->enable & ~RPCIF_SMENR_SPIDE(0xF));
>>>> -    regmap_write(rpc->regmap, RPCIF_DRDMCR, rpc->dummy);
>>>> -    regmap_write(rpc->regmap, RPCIF_DRDRENR, rpc->ddr);
>>>
>>>      The driver somehow works only with this left in place (with 2 bytes eaten
>>> as before), otherwise all the flash reads all 0xff (via dirmap).
>>
>>
>> Do you boot from hyperflash?
> 
>     No, I have arewto say 'cpld write 30 1' in U-Boot before a boot a kernel.
> Normally, the V3x Starter Kit boards are wired for the QSPI flash chips.
> 
>> The system I'm using for testing boots from hyperflash. So most probably all registers
>> I don't touch in the driver are put into a reasonable state by the boot code, already.
>> If you don't boot from hyperflash, that at least would explain our different behavior.
> 
>     Yes. Mind dumping the registers and sending to me?


Using the attached debug patch 
(0001-memory-renesas-rpc-if-DEBUG-Dump-register-content.patch) on a 
r8a7796 system booting from Hyperflash with above register dropping 
reverted (i.e. including touching these registers) I get

Before:
RPCIF_DRCR:    0x00000000
RPCIF_DRCMR:   0x00a00000
RPCIF_DREAR:   0x00000000
RPCIF_DROPR:   0x00000000
RPCIF_DRENR:   0xa222d400
RPCIF_DRDMCR:  0x0000000e
RPCIF_DRDRENR: 0x00005101

After:
RPCIF_DRCR:    0x001f0100
RPCIF_DRCMR:   0x00a00000
RPCIF_DREAR:   0x00010001
RPCIF_DROPR:   0x00000000
RPCIF_DRENR:   0xa202d400
RPCIF_DRDMCR:  0x0000000e
RPCIF_DRDRENR: 0x00005101

Comparing that, just 3 registers are different between my working 
version ("Before") and the version which shows the 2-byte offset 
("After"): RPCIF_DRCR, RPCIF_DREAR and RPCIF_DRENR. With try & error, at 
least in my setup, I was able to reduce this to just RPCIF_DRCR. 
Dropping the burst mode I was able to 'fix' the two byte offset issue.

Do you like to give the attached 
0001-memory-renesas-rpc-if-Don-t-use-burst-mode-on-read.patch a try in 
your setup?

Best regards

Dirk


[-- Attachment #2: 0001-memory-renesas-rpc-if-DEBUG-Dump-register-content.patch --]
[-- Type: text/plain, Size: 2876 bytes --]

From 8942c771f8ea8957a14fc6f6e4443675c4b6b260 Mon Sep 17 00:00:00 2001
From: Dirk Behme <dirk.behme@de.bosch.com>
Date: Tue, 25 Feb 2020 07:57:12 +0100
Subject: [PATCH] memory: renesas-rpc-if: DEBUG: Dump register content

Dump register content before and after being modified by the driver.

Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>
---
 drivers/memory/renesas-rpc-if.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/drivers/memory/renesas-rpc-if.c b/drivers/memory/renesas-rpc-if.c
index 4853e7f78985..4486de0b517b 100644
--- a/drivers/memory/renesas-rpc-if.c
+++ b/drivers/memory/renesas-rpc-if.c
@@ -517,12 +517,23 @@ ssize_t rpcif_dirmap_read(struct rpcif *rpc, u64 offs, size_t len, void *buf)
 {
 	loff_t from = offs & (RPCIF_DIRMAP_SIZE - 1);
 	size_t size = RPCIF_DIRMAP_SIZE - from;
+	u32 data;
 
 	if (len > size)
 		len = size;
 
 	pm_runtime_get_sync(rpc->dev);
 
+	pr_err("Before:\n");
+	regmap_read(rpc->regmap, RPCIF_CMNCR, &data);   pr_err("RPCIF_CMNCR:   0x%08x\n", data);
+	regmap_read(rpc->regmap, RPCIF_DRCR, &data);    pr_err("RPCIF_DRCR:    0x%08x\n", data);
+	regmap_read(rpc->regmap, RPCIF_DRCMR, &data);   pr_err("RPCIF_DRCMR:   0x%08x\n", data);
+	regmap_read(rpc->regmap, RPCIF_DREAR, &data);   pr_err("RPCIF_DREAR:   0x%08x\n", data);
+	regmap_read(rpc->regmap, RPCIF_DROPR, &data);   pr_err("RPCIF_DROPR:   0x%08x\n", data);
+	regmap_read(rpc->regmap, RPCIF_DRENR, &data);   pr_err("RPCIF_DRENR:   0x%08x\n", data);
+	regmap_read(rpc->regmap, RPCIF_DRDMCR, &data);  pr_err("RPCIF_DRDMCR:  0x%08x\n", data);
+	regmap_read(rpc->regmap, RPCIF_DRDRENR, &data); pr_err("RPCIF_DRDRENR: 0x%08x\n", data);
+
 	regmap_update_bits(rpc->regmap, RPCIF_CMNCR, RPCIF_CMNCR_MD, 0);
 	regmap_write(rpc->regmap, RPCIF_DRCR,
 		     RPCIF_DRCR_RBURST(32) | RPCIF_DRCR_RBE);
@@ -535,6 +546,16 @@ ssize_t rpcif_dirmap_read(struct rpcif *rpc, u64 offs, size_t len, void *buf)
 	regmap_write(rpc->regmap, RPCIF_DRDMCR, rpc->dummy);
 	regmap_write(rpc->regmap, RPCIF_DRDRENR, rpc->ddr);
 
+	pr_err("After:\n");
+	regmap_read(rpc->regmap, RPCIF_CMNCR, &data);   pr_err("RPCIF_CMNCR:   0x%08x\n", data);
+	regmap_read(rpc->regmap, RPCIF_DRCR, &data);    pr_err("RPCIF_DRCR:    0x%08x\n", data);
+	regmap_read(rpc->regmap, RPCIF_DRCMR, &data);   pr_err("RPCIF_DRCMR:   0x%08x\n", data);
+	regmap_read(rpc->regmap, RPCIF_DREAR, &data);   pr_err("RPCIF_DREAR:   0x%08x\n", data);
+	regmap_read(rpc->regmap, RPCIF_DROPR, &data);   pr_err("RPCIF_DROPR:   0x%08x\n", data);
+	regmap_read(rpc->regmap, RPCIF_DRENR, &data);   pr_err("RPCIF_DRENR:   0x%08x\n", data);
+	regmap_read(rpc->regmap, RPCIF_DRDMCR, &data);  pr_err("RPCIF_DRDMCR:  0x%08x\n", data);
+	regmap_read(rpc->regmap, RPCIF_DRDRENR, &data); pr_err("RPCIF_DRDRENR: 0x%08x\n", data);
+
 	memcpy_fromio(buf, rpc->dirmap + from, len);
 
 	pm_runtime_put(rpc->dev);
-- 
2.20.0


[-- Attachment #3: 0001-memory-renesas-rpc-if-Don-t-use-burst-mode-on-read.patch --]
[-- Type: text/plain, Size: 1195 bytes --]

From 189d30a8e9670f1a5a1e9d3b257f14b7df7bc172 Mon Sep 17 00:00:00 2001
From: Dirk Behme <dirk.behme@de.bosch.com>
Date: Tue, 25 Feb 2020 08:41:06 +0100
Subject: [PATCH] memory: renesas-rpc-if: Don't use burst mode on read

Testing shows that enabling the burst mode results in a "2-byte offset"
in read data. Dropping the burst mode seems to fix this.

Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>
---
 drivers/memory/renesas-rpc-if.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/memory/renesas-rpc-if.c b/drivers/memory/renesas-rpc-if.c
index 4853e7f78985..2d77eca7aaa5 100644
--- a/drivers/memory/renesas-rpc-if.c
+++ b/drivers/memory/renesas-rpc-if.c
@@ -524,8 +524,7 @@ ssize_t rpcif_dirmap_read(struct rpcif *rpc, u64 offs, size_t len, void *buf)
 	pm_runtime_get_sync(rpc->dev);
 
 	regmap_update_bits(rpc->regmap, RPCIF_CMNCR, RPCIF_CMNCR_MD, 0);
-	regmap_write(rpc->regmap, RPCIF_DRCR,
-		     RPCIF_DRCR_RBURST(32) | RPCIF_DRCR_RBE);
+	regmap_write(rpc->regmap, RPCIF_DRCR, 0);
 	regmap_write(rpc->regmap, RPCIF_DRCMR, rpc->command);
 	regmap_write(rpc->regmap, RPCIF_DREAR,
 		     RPCIF_DREAR_EAV(offs >> 25) | RPCIF_DREAR_EAC(1));
-- 
2.20.0

Re: [PATCH RFC 2/2] memory: add Renesas RPC-IF driver

[Sergei Shtylyov]

On 02/25/2020 12:33 PM, Behme Dirk (CM/ESO2) wrote:

>>>>>   From d72b805cc461ab1e9747c973e9be84e7abb8f828 Mon Sep 17 00:00:00 2001
>>>>> From: Dirk Behme <dirk.behme-V5te9oGctAVWk0Htik3J/w@public.gmane.org>
>>>>> Date: Tue, 4 Feb 2020 08:39:31 +0100
>>>>> Subject: [PATCH] memory: renesas-rpc-if: Correct the STRTIM and some other
>>>>>    clean up
>>>>>
>>>>> This is required to make the driver work correctly in my M3 environment.
>>>>>
>>>>> Signed-off-by: Dirk Behme <dirk.behme-V5te9oGctAVWk0Htik3J/w@public.gmane.org>
>>>>> ---
>>>>>    drivers/memory/renesas-rpc-if.c | 42 ++++++++++++++++++++-------------
>>>>>    1 file changed, 25 insertions(+), 17 deletions(-)
>>>>>
>>>>> diff --git a/drivers/memory/renesas-rpc-if.c b/drivers/memory/renesas-rpc-if.c
>>>>> index 04be92b64bfa..f4356b066384 100644
>>>>> --- a/drivers/memory/renesas-rpc-if.c
>>>>> +++ b/drivers/memory/renesas-rpc-if.c
>>>> [...]
>>>>> @@ -513,19 +525,15 @@ ssize_t rpcif_dirmap_read(struct rpcif *rpc, u64 offs, size_t len, void *buf)
>>>>>        pm_runtime_get_sync(rpc->dev);
>>>>>
>>>>>        regmap_update_bits(rpc->regmap, RPCIF_CMNCR, RPCIF_CMNCR_MD, 0);
>>>>> -    regmap_write(rpc->regmap, RPCIF_DRCR,
>>>>> -             RPCIF_DRCR_RBURST(32) | RPCIF_DRCR_RBE);
>>>>> -    regmap_write(rpc->regmap, RPCIF_DRCMR, rpc->command);
>>>>> -    regmap_write(rpc->regmap, RPCIF_DREAR,
>>>>> -             RPCIF_DREAR_EAV(offs >> 25) | RPCIF_DREAR_EAC(1));
>>>>> -    regmap_write(rpc->regmap, RPCIF_DROPR, rpc->option);
>>>>> -    regmap_write(rpc->regmap, RPCIF_DRENR,
>>>>> -             rpc->enable & ~RPCIF_SMENR_SPIDE(0xF));
>>>>> -    regmap_write(rpc->regmap, RPCIF_DRDMCR, rpc->dummy);
>>>>> -    regmap_write(rpc->regmap, RPCIF_DRDRENR, rpc->ddr);
>>>>
>>>>      The driver somehow works only with this left in place (with 2 bytes eaten
>>>> as before), otherwise all the flash reads all 0xff (via dirmap).
>>>
>>>
>>> Do you boot from hyperflash?
>>
>>     No, I have arewto say 'cpld write 30 1' in U-Boot before a boot a kernel.

   s/arewto/to/. :-)

>> Normally, the V3x Starter Kit boards are wired for the QSPI flash chips.
>>
>>> The system I'm using for testing boots from hyperflash. So most probably all registers
>>> I don't touch in the driver are put into a reasonable state by the boot code, already.
>>> If you don't boot from hyperflash, that at least would explain our different behavior.
>>
>>     Yes. Mind dumping the registers and sending to me?
> 
> Using the attached debug patch (0001-memory-renesas-rpc-if-DEBUG-Dump-register-
> content.patch) on a r8a7796 system booting from Hyperflash with above register
dropping reverted (i.e. including touching these registers) I get
> 
> Before:
> RPCIF_DRCR:    0x00000000
> RPCIF_DRCMR:   0x00a00000
> RPCIF_DREAR:   0x00000000
> RPCIF_DROPR:   0x00000000
> RPCIF_DRENR:   0xa222d400
> RPCIF_DRDMCR:  0x0000000e
> RPCIF_DRDRENR: 0x00005101
> 
> After:
> RPCIF_DRCR:    0x001f0100
> RPCIF_DRCMR:   0x00a00000
> RPCIF_DREAR:   0x00010001
> RPCIF_DROPR:   0x00000000
> RPCIF_DRENR:   0xa202d400
> RPCIF_DRDMCR:  0x0000000e
> RPCIF_DRDRENR: 0x00005101
> 
> Comparing that, just 3 registers are different between my working version ("Before") and the version which shows the 2-byte offset ("After"): RPCIF_DRCR, RPCIF_DREAR and RPCIF_DRENR. With try & error, at least in my setup, I was able to reduce this to just RPCIF_DRCR. Dropping the burst mode I was able to 'fix' the two byte offset issue.

   ACK! Thanks a lot for finding it! :-)
   That's what I get on the first dirmap read:

Before:
RPCIF_CMNCR:   0x81fff301
RPCIF_DRCR:    0x00000000
RPCIF_DRCMR:   0x00030000
RPCIF_DREAR:   0x00000000
RPCIF_DROPR:   0x00000000
RPCIF_DRENR:   0x00004700
RPCIF_DRDMCR:  0x00000000
RPCIF_DRDRENR: 0x00000000

After:                                                                          
RPCIF_CMNCR:   0x01fff301                                                       
RPCIF_DRCR:    0x001f0100                                                       
RPCIF_DRCMR:   0x00800000                                                       
RPCIF_DREAR:   0x00000001                                                       
RPCIF_DROPR:   0x00000000                                                       
RPCIF_DRENR:   0xa202d400                                                       
RPCIF_DRDMCR:  0x0000000e                                                       
RPCIF_DRDRENR: 0x00005101                                                       

> Do you like to give the attached 0001-memory-renesas-rpc-if-Don-t-use-burst-mode-on-read.patch a try in your setup?

   Works like charm! :-)
   Unfortunately, the SPI dirmap and/or writes are still broken.

> Best regards
> 
> Dirk

MBR, Sergei

Re: [PATCH RFC 2/2] memory: add Renesas RPC-IF driver

[Behme Dirk (CM/ESO2)]

Hi Sergei,

On 25.02.2020 21:41, Sergei Shtylyov wrote:
> On 02/25/2020 12:33 PM, Behme Dirk (CM/ESO2) wrote:
> 
>>>>>>    From d72b805cc461ab1e9747c973e9be84e7abb8f828 Mon Sep 17 00:00:00 2001
>>>>>> From: Dirk Behme <dirk.behme-V5te9oGctAVWk0Htik3J/w@public.gmane.org>
>>>>>> Date: Tue, 4 Feb 2020 08:39:31 +0100
>>>>>> Subject: [PATCH] memory: renesas-rpc-if: Correct the STRTIM and some other
>>>>>>     clean up
>>>>>>
>>>>>> This is required to make the driver work correctly in my M3 environment.
>>>>>>
>>>>>> Signed-off-by: Dirk Behme <dirk.behme-V5te9oGctAVWk0Htik3J/w@public.gmane.org>
>>>>>> ---
>>>>>>     drivers/memory/renesas-rpc-if.c | 42 ++++++++++++++++++++-------------
>>>>>>     1 file changed, 25 insertions(+), 17 deletions(-)
>>>>>>
>>>>>> diff --git a/drivers/memory/renesas-rpc-if.c b/drivers/memory/renesas-rpc-if.c
>>>>>> index 04be92b64bfa..f4356b066384 100644
>>>>>> --- a/drivers/memory/renesas-rpc-if.c
>>>>>> +++ b/drivers/memory/renesas-rpc-if.c
>>>>> [...]
>>>>>> @@ -513,19 +525,15 @@ ssize_t rpcif_dirmap_read(struct rpcif *rpc, u64 offs, size_t len, void *buf)
>>>>>>         pm_runtime_get_sync(rpc->dev);
>>>>>>
>>>>>>         regmap_update_bits(rpc->regmap, RPCIF_CMNCR, RPCIF_CMNCR_MD, 0);
>>>>>> -    regmap_write(rpc->regmap, RPCIF_DRCR,
>>>>>> -             RPCIF_DRCR_RBURST(32) | RPCIF_DRCR_RBE);
>>>>>> -    regmap_write(rpc->regmap, RPCIF_DRCMR, rpc->command);
>>>>>> -    regmap_write(rpc->regmap, RPCIF_DREAR,
>>>>>> -             RPCIF_DREAR_EAV(offs >> 25) | RPCIF_DREAR_EAC(1));
>>>>>> -    regmap_write(rpc->regmap, RPCIF_DROPR, rpc->option);
>>>>>> -    regmap_write(rpc->regmap, RPCIF_DRENR,
>>>>>> -             rpc->enable & ~RPCIF_SMENR_SPIDE(0xF));
>>>>>> -    regmap_write(rpc->regmap, RPCIF_DRDMCR, rpc->dummy);
>>>>>> -    regmap_write(rpc->regmap, RPCIF_DRDRENR, rpc->ddr);
>>>>>
>>>>>       The driver somehow works only with this left in place (with 2 bytes eaten
>>>>> as before), otherwise all the flash reads all 0xff (via dirmap).
>>>>
>>>>
>>>> Do you boot from hyperflash?
>>>
>>>      No, I have arewto say 'cpld write 30 1' in U-Boot before a boot a kernel.
> 
>     s/arewto/to/. :-)
> 
>>> Normally, the V3x Starter Kit boards are wired for the QSPI flash chips.
>>>
>>>> The system I'm using for testing boots from hyperflash. So most probably all registers
>>>> I don't touch in the driver are put into a reasonable state by the boot code, already.
>>>> If you don't boot from hyperflash, that at least would explain our different behavior.
>>>
>>>      Yes. Mind dumping the registers and sending to me?
>>
>> Using the attached debug patch (0001-memory-renesas-rpc-if-DEBUG-Dump-register-
>> content.patch) on a r8a7796 system booting from Hyperflash with above register
> dropping reverted (i.e. including touching these registers) I get
>>
>> Before:
>> RPCIF_DRCR:    0x00000000
>> RPCIF_DRCMR:   0x00a00000
>> RPCIF_DREAR:   0x00000000
>> RPCIF_DROPR:   0x00000000
>> RPCIF_DRENR:   0xa222d400
>> RPCIF_DRDMCR:  0x0000000e
>> RPCIF_DRDRENR: 0x00005101
>>
>> After:
>> RPCIF_DRCR:    0x001f0100
>> RPCIF_DRCMR:   0x00a00000
>> RPCIF_DREAR:   0x00010001
>> RPCIF_DROPR:   0x00000000
>> RPCIF_DRENR:   0xa202d400
>> RPCIF_DRDMCR:  0x0000000e
>> RPCIF_DRDRENR: 0x00005101
>>
>> Comparing that, just 3 registers are different between my working version ("Before") and the version which shows the 2-byte offset ("After"): RPCIF_DRCR, RPCIF_DREAR and RPCIF_DRENR. With try & error, at least in my setup, I was able to reduce this to just RPCIF_DRCR. Dropping the burst mode I was able to 'fix' the two byte offset issue.
> 
>     ACK! Thanks a lot for finding it! :-)
>     That's what I get on the first dirmap read:
> 
> Before:
> RPCIF_CMNCR:   0x81fff301
> RPCIF_DRCR:    0x00000000
> RPCIF_DRCMR:   0x00030000
> RPCIF_DREAR:   0x00000000
> RPCIF_DROPR:   0x00000000
> RPCIF_DRENR:   0x00004700
> RPCIF_DRDMCR:  0x00000000
> RPCIF_DRDRENR: 0x00000000
> 
> After:
> RPCIF_CMNCR:   0x01fff301
> RPCIF_DRCR:    0x001f0100
> RPCIF_DRCMR:   0x00800000
> RPCIF_DREAR:   0x00000001
> RPCIF_DROPR:   0x00000000
> RPCIF_DRENR:   0xa202d400
> RPCIF_DRDMCR:  0x0000000e
> RPCIF_DRDRENR: 0x00005101
> 
>> Do you like to give the attached 0001-memory-renesas-rpc-if-Don-t-use-burst-mode-on-read.patch a try in your setup?
> 
>     Works like charm! :-)


Good news, thanks! :)


>     Unfortunately, the SPI dirmap and/or writes are still broken.


I'm unsure about which function we are talking for "SPI dirmap"?

Regarding writes, in rpcif_io_xfer() in RPCIF_DATA_IN we have an 
additional place where burst mode is enabled:

if (!(smenr & RPCIF_SMENR_ADE(0xf)) && rpc->dirmap) {
...
regmap_write(rpc->regmap, RPCIF_DRCR,
	RPCIF_DRCR_RBURST(32) | RPCIF_DRCR_RBE);
...

Maybe it's worth a try to replace this by just 0, as well:

regmap_write(rpc->regmap, RPCIF_DRCR, 0);

But of course, this is guessing, as I'm not sure if this

if (!(smenr & RPCIF_SMENR_ADE(0xf)) && rpc->dirmap) {

path is taken, at all?


Or even better, if you could adapt the "before / after" debug patch to 
the path which are still not working for you and share it and the 
results, we could compare it with my setup, too :)

Dirk

Re: [PATCH RFC 2/2] memory: add Renesas RPC-IF driver

[Sergei Shtylyov]

Hello!

On 02/26/2020 12:54 PM, Behme Dirk (CM/ESO2) wrote:

>>>>>>>    From d72b805cc461ab1e9747c973e9be84e7abb8f828 Mon Sep 17 00:00:00 2001
>>>>>>> From: Dirk Behme <dirk.behme@de.bosch.com>
>>>>>>> Date: Tue, 4 Feb 2020 08:39:31 +0100
>>>>>>> Subject: [PATCH] memory: renesas-rpc-if: Correct the STRTIM and some other
>>>>>>>     clean up
>>>>>>>
>>>>>>> This is required to make the driver work correctly in my M3 environment.
>>>>>>>
>>>>>>> Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>
>>>>>>> ---
>>>>>>>     drivers/memory/renesas-rpc-if.c | 42 ++++++++++++++++++++-------------
>>>>>>>     1 file changed, 25 insertions(+), 17 deletions(-)
>>>>>>>
>>>>>>> diff --git a/drivers/memory/renesas-rpc-if.c b/drivers/memory/renesas-rpc-if.c
>>>>>>> index 04be92b64bfa..f4356b066384 100644
>>>>>>> --- a/drivers/memory/renesas-rpc-if.c
>>>>>>> +++ b/drivers/memory/renesas-rpc-if.c
>>>>>> [...]
>>>>>>> @@ -513,19 +525,15 @@ ssize_t rpcif_dirmap_read(struct rpcif *rpc, u64 offs, size_t len, void *buf)
>>>>>>>         pm_runtime_get_sync(rpc->dev);
>>>>>>>
>>>>>>>         regmap_update_bits(rpc->regmap, RPCIF_CMNCR, RPCIF_CMNCR_MD, 0);
>>>>>>> -    regmap_write(rpc->regmap, RPCIF_DRCR,
>>>>>>> -             RPCIF_DRCR_RBURST(32) | RPCIF_DRCR_RBE);
>>>>>>> -    regmap_write(rpc->regmap, RPCIF_DRCMR, rpc->command);
>>>>>>> -    regmap_write(rpc->regmap, RPCIF_DREAR,
>>>>>>> -             RPCIF_DREAR_EAV(offs >> 25) | RPCIF_DREAR_EAC(1));
>>>>>>> -    regmap_write(rpc->regmap, RPCIF_DROPR, rpc->option);
>>>>>>> -    regmap_write(rpc->regmap, RPCIF_DRENR,
>>>>>>> -             rpc->enable & ~RPCIF_SMENR_SPIDE(0xF));
>>>>>>> -    regmap_write(rpc->regmap, RPCIF_DRDMCR, rpc->dummy);
>>>>>>> -    regmap_write(rpc->regmap, RPCIF_DRDRENR, rpc->ddr);
>>>>>>
>>>>>>       The driver somehow works only with this left in place (with 2 bytes eaten
>>>>>> as before), otherwise all the flash reads all 0xff (via dirmap).
>>>>>
>>>>>
>>>>> Do you boot from hyperflash?
>>>>
>>>>      No, I have arewto say 'cpld write 30 1' in U-Boot before a boot a kernel.
>>
>>     s/arewto/to/. :-)
>>
>>>> Normally, the V3x Starter Kit boards are wired for the QSPI flash chips.
>>>>
>>>>> The system I'm using for testing boots from hyperflash. So most probably all registers
>>>>> I don't touch in the driver are put into a reasonable state by the boot code, already.
>>>>> If you don't boot from hyperflash, that at least would explain our different behavior.
>>>>
>>>>      Yes. Mind dumping the registers and sending to me?
>>>
>>> Using the attached debug patch (0001-memory-renesas-rpc-if-DEBUG-Dump-register-
>>> content.patch) on a r8a7796 system booting from Hyperflash with above register
>> dropping reverted (i.e. including touching these registers) I get
>>>
>>> Before:
>>> RPCIF_DRCR:    0x00000000
>>> RPCIF_DRCMR:   0x00a00000
>>> RPCIF_DREAR:   0x00000000
>>> RPCIF_DROPR:   0x00000000
>>> RPCIF_DRENR:   0xa222d400
>>> RPCIF_DRDMCR:  0x0000000e
>>> RPCIF_DRDRENR: 0x00005101
>>>
>>> After:
>>> RPCIF_DRCR:    0x001f0100
>>> RPCIF_DRCMR:   0x00a00000
>>> RPCIF_DREAR:   0x00010001
>>> RPCIF_DROPR:   0x00000000
>>> RPCIF_DRENR:   0xa202d400
>>> RPCIF_DRDMCR:  0x0000000e
>>> RPCIF_DRDRENR: 0x00005101
>>>
>>> Comparing that, just 3 registers are different between my working version ("Before") and the version which shows the 2-byte offset ("After"): RPCIF_DRCR, RPCIF_DREAR and RPCIF_DRENR. With try & error, at least in my setup, I was able to reduce this to just RPCIF_DRCR. Dropping the burst mode I was able to 'fix' the two byte offset issue.
>>
>>     ACK! Thanks a lot for finding it! :-)
>>     That's what I get on the first dirmap read:
>>
>> Before:
>> RPCIF_CMNCR:   0x81fff301
>> RPCIF_DRCR:    0x00000000
>> RPCIF_DRCMR:   0x00030000
>> RPCIF_DREAR:   0x00000000
>> RPCIF_DROPR:   0x00000000
>> RPCIF_DRENR:   0x00004700
>> RPCIF_DRDMCR:  0x00000000
>> RPCIF_DRDRENR: 0x00000000
>>
>> After:
>> RPCIF_CMNCR:   0x01fff301
>> RPCIF_DRCR:    0x001f0100
>> RPCIF_DRCMR:   0x00800000
>> RPCIF_DREAR:   0x00000001
>> RPCIF_DROPR:   0x00000000
>> RPCIF_DRENR:   0xa202d400
>> RPCIF_DRDMCR:  0x0000000e
>> RPCIF_DRDRENR: 0x00005101
>>
>>> Do you like to give the attached 0001-memory-renesas-rpc-if-Don-t-use-burst-mode-on-read.patch a try in your setup?
>>
>>     Works like charm! :-)
> 
> 
> Good news, thanks! :)
> 
> 
>>     Unfortunately, the SPI dirmap and/or writes are still broken.
> 
> 
> I'm unsure about which function we are talking for "SPI dirmap"?

   The same, rpcif_dirmap_read(). I'm now thinking it works correctly, it's just
the writes that are borked.

> Regarding writes, in rpcif_io_xfer() in RPCIF_DATA_IN we have an additional place where burst mode is enabled:

   This works around the hardware bug where the SPI NOR RDID command's data bytes get
spoiled, leading to unrecognized flash chip. Well, there's a comment before this *if*. 

> if (!(smenr & RPCIF_SMENR_ADE(0xf)) && rpc->dirmap) {
> ...
> regmap_write(rpc->regmap, RPCIF_DRCR,
>     RPCIF_DRCR_RBURST(32) | RPCIF_DRCR_RBE);
> ...
> 
> Maybe it's worth a try to replace this by just 0, as well:
> 
> regmap_write(rpc->regmap, RPCIF_DRCR, 0);

   I've just tried that, here's the result:

spi-nor spi0.0: unrecognized JEDEC id bytes: 01 01 01 01 01 01                  

(and the flash doesn't get registered).

> But of course, this is guessing, as I'm not sure if this
> 
> if (!(smenr & RPCIF_SMENR_ADE(0xf)) && rpc->dirmap) {
> 
> path is taken, at all?

   It's taken but only with SPI NOR.

> Or even better, if you could adapt the "before / after" debug patch to the path which are still not working for you and share it and the results, we could compare it with my setup, too :)

  I'll try doing that tomorrow...

> Dirk

MBR, Sergei

RE: [PATCH RFC 0/2] Add Renesas RPC-IF support

[Chris Brandt]

Hello Sergei,

On Tue, Dec 10, 2019, Sergei Shtylyov wrote:
> Here's a set of 2 patches against Linus' repo. Renesas Reduced Pin Count
> Interface (RPC-IF) allows a SPI flash or HyperFlash connected to the SoC to
> be accessed via the external address space read mode or the manual mode.

Looking at this driver, all it is are APIs. Meaning another driver is 
needed to sit in between the MTD layer and this HW driver layer.

In the driver that I did, if the "RPC" HW is going to be used to control
a SPI Flash device, it registered a spi controller and then the MTD 
layer could access the device just like any other SPI controller driver. No
additional drivers are needed.

Looking at the hyperbus driver that is in drivers/mtd/hyperbus/, it 
seems that if the "RPC" HW is going to be used to control HyperFlash, then 
all you would need to do is register a hyperbus controller using 
hyperbus_register_device(). Then the MTD layer could read/write the flash using 
normal MTD CFI interface.

Why do you think you need another layer in between the HW driver and the
MTD layer?
Is your goal to make a multi-layered system where the HW jumps back and forth
in between operating modes at runtime? I'm not sure of the use case for all of
this.

Chris

Re: [PATCH RFC 0/2] Add Renesas RPC-IF support

[Sergei Shtylyov]

HEllo

On 12/11/2019 05:33 PM, Chris Brandt wrote:

>> Here's a set of 2 patches against Linus' repo. Renesas Reduced Pin Count
>> Interface (RPC-IF) allows a SPI flash or HyperFlash connected to the SoC to
>> be accessed via the external address space read mode or the manual mode.
> 
> Looking at this driver, all it is are APIs. Meaning another driver is 
> needed to sit in between the MTD layer and this HW driver layer.

   Between the hardware and SPI, and between the hardware and HyperFlash
infrastructure. There's a lot of the common hardware code common between
these 2 driver areas.

> In the driver that I did, if the "RPC" HW is going to be used to control
> a SPI Flash device, it registered a spi controller and then the MTD 
> layer could access the device just like any other SPI controller driver. No
> additional drivers are needed.

   We're already been thru that with Mason's patch -- I don't want the code
duplicated between 2 drivers.

> Looking at the hyperbus driver that is in drivers/mtd/hyperbus/, it 
> seems that if the "RPC" HW is going to be used to control HyperFlash, then 

   Sure. But the code controlling RPC hardware is largely the same b/w 2 cases.

> all you would need to do is register a hyperbus controller using 
> hyperbus_register_device(). Then the MTD layer could read/write the flash using 
> normal MTD CFI interface.

   That's what I do (the current realization makes too many assumptions about
the HF hardware (both direct read and write). 

> Why do you think you need another layer in between the HW driver and the
> MTD layer?

   Because we don't want any duplicated code. Also, think about DT -- it
describes the hardware, not the driver configuration.

> Is your goal to make a multi-layered system where the HW jumps back and forth
> in between operating modes at runtime? I'm not sure of the use case for all of
> this.

   My goal is to prevent the code duplication (and keep DT sane too).

> Chris

MBR, Sergei

Re: [PATCH RFC 0/2] Add Renesas RPC-IF support

[Sergei Shtylyov]

On 12/11/2019 05:33 PM, Chris Brandt wrote:

>> Here's a set of 2 patches against Linus' repo. Renesas Reduced Pin Count
>> Interface (RPC-IF) allows a SPI flash or HyperFlash connected to the SoC to
>> be accessed via the external address space read mode or the manual mode.
> 
> Looking at this driver, all it is are APIs. Meaning another driver is 
> needed to sit in between the MTD layer and this HW driver layer.
> 
> In the driver that I did, if the "RPC" HW is going to be used to control
> a SPI Flash device, it registered a spi controller and then the MTD 
> layer could access the device

   Via the SPI-to-MTD sublayer for (at least) direct mapping -- grep for "dirmap"
in drivers/mtd/spi-nor/spi-nor.c...

> just like any other SPI controller driver. No
> additional drivers are needed.

   Then why do we have *struct* spi_controller_mem_ops? Do All drivers implement
such ops?

[...]

MBR, Sergei