[PATCH v3 0/5] MTD: Add Initial Hyperbus support

[PATCH v3 0/5] MTD: Add Initial Hyperbus support

[Vignesh Raghavendra]

Cypress HyperBus is Low Signal Count, High Performance Double Data Rate Bus
interface between a host system master and one or more slave interfaces.
HyperBus is used to connect microprocessor, microcontroller, or ASIC
devices with random access NOR flash memory(called HyperFlash) or
self refresh DRAM(called HyperRAM).

Its a 8-bit data bus (DQ[7:0]) with  Read-Write Data Strobe (RWDS)
signal and either Single-ended clock(3.0V parts) or Differential clock
(1.8V parts). It uses ChipSelect lines to select b/w multiple slaves.
At bus level, it follows a separate protocol described in HyperBus
specification[1].

HyperFlash follows CFI AMD/Fujitsu Extended Command Set (0x0002) similar
to that of existing parallel NORs. Since Hyperbus is x8 DDR bus,
its equivalent to x16 parallel NOR flash wrt bits per clk. But Hyperbus
operates at >166MHz frequencies.
HyperRAM provides direct random read/write access to flash memory
array.
Framework is modelled along the lines of spi-nor framework. HyperBus
memory controller(HBMC) drivers call hyperbus_register_device() to register a
single HyperFlash device. HyperFlash core parses MMIO access
information from DT, sets up the map_info struct, probes CFI flash and
registers it with MTD framework.

This is an early RFC, to know if its okay to use maps framework and existing
CFI compliant flash support code to support Hyperflash
Also would like input on different types of HBMC master IPs out there
and their programming sequences.
Would appreciate any testing/review.

Tested on modified TI AM654 EVM with Cypress Hyperflash S26KS512 by
creating a UBIFS partition and writing and reading files to it.
Stress tested by writing/reading 16MB flash repeatedly at different
offsets using dd commmand.

HyperBus specification can be found at[1]
HyperFlash datasheet can be found at[2]
TI's HBMC controller details at[3]

[1] https://www.cypress.com/file/213356/download
[2] https://www.cypress.com/file/213346/download
[3] http://www.ti.com/lit/ug/spruid7b/spruid7b.pdf
    Table 12-5741. HyperFlash Access Sequence

Change log:
Since RFC v2:
* use map_word_xxx() for handling status register to support interleaved
  flashes as suggested by Joakim Tjernlund <Joakim.Tjernlund@infinera.com>
* Report error status/messages on erase/program failure by looking at
  status register bits.
* Add "cfi-flash" as fallback compatible for cypress,hyperflash
* Add support to select between HyperBus and OSPI using mmio mux

Since RFC v1:
* Re-work Hyperbus core to provide separate struct representation for
  controller and slave devices
* Rename all files and func names to have hyperbus_ prefix
* Provide default calibration routine for use by controller drivers
* Fix up errors with patch spliting
* Address comments by Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>


Vignesh Raghavendra (5):
  mtd: cfi_cmdset_0002: Add support for polling status register
  dt-bindings: mtd: Add binding documentation for HyperFlash
  mtd: Add support for HyperBus memory devices
  dt-bindings: mtd: Add bindings for TI's AM654 HyperBus memory
    controller
  mtd: hyperbus: Add driver for TI's HyperBus memory controller

 .../bindings/mtd/cypress,hyperflash.txt       |   6 +
 .../devicetree/bindings/mtd/ti,am654-hbmc.txt |  31 +++
 MAINTAINERS                                   |   8 +
 drivers/mtd/Kconfig                           |   2 +
 drivers/mtd/Makefile                          |   1 +
 drivers/mtd/chips/cfi_cmdset_0002.c           |  90 ++++++++
 drivers/mtd/hyperbus/Kconfig                  |  23 +++
 drivers/mtd/hyperbus/Makefile                 |   4 +
 drivers/mtd/hyperbus/hbmc-am654.c             | 115 +++++++++++
 drivers/mtd/hyperbus/hyperbus-core.c          | 192 ++++++++++++++++++
 include/linux/mtd/cfi.h                       |   5 +
 include/linux/mtd/hyperbus.h                  |  91 +++++++++
 12 files changed, 568 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mtd/cypress,hyperflash.txt
 create mode 100644 Documentation/devicetree/bindings/mtd/ti,am654-hbmc.txt
 create mode 100644 drivers/mtd/hyperbus/Kconfig
 create mode 100644 drivers/mtd/hyperbus/Makefile
 create mode 100644 drivers/mtd/hyperbus/hbmc-am654.c
 create mode 100644 drivers/mtd/hyperbus/hyperbus-core.c
 create mode 100644 include/linux/mtd/hyperbus.h

-- 
2.21.0

[PATCH v3 1/5] mtd: cfi_cmdset_0002: Add support for polling status register

[Vignesh Raghavendra]

HyperFlash devices are compliant with CFI AMD/Fujitsu Extended Command
Set(0x0002) for flash operations, therefore drivers/mtd/chips/cfi_cmdset_0002.c
can be used as is. But these devices do not support DQ polling method of
determining chip ready/good status. These flashes provide Status
Register whose bits can be polled to know status of flash operation.

Cypress HyperFlash datasheet here[1], talks about CFI Amd/Fujitsu
Extended Query version 1.5. Bit 0 of "Software Features supported" field
of CFI Primary Vendor-Specific Extended Query table indicates
presence/absence of status register and Bit 1 indicates whether or not
DQ polling is supported. Using these bits, its possible to determine
whether flash supports DQ polling or need to use Status Register.

Add support for polling Status Register to know device ready/status of
erase/write operations when DQ polling is not supported.
Print error messages on erase/program failure by looking at related
Status Register bits.

[1] https://www.cypress.com/file/213346/download

Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
---
 drivers/mtd/chips/cfi_cmdset_0002.c | 90 +++++++++++++++++++++++++++++
 include/linux/mtd/cfi.h             |  5 ++
 2 files changed, 95 insertions(+)

diff --git a/drivers/mtd/chips/cfi_cmdset_0002.c b/drivers/mtd/chips/cfi_cmdset_0002.c
index 7b7286b4d81e..55c4d81098d5 100644
--- a/drivers/mtd/chips/cfi_cmdset_0002.c
+++ b/drivers/mtd/chips/cfi_cmdset_0002.c
@@ -49,6 +49,16 @@
 #define SST49LF008A		0x005a
 #define AT49BV6416		0x00d6
 
+/*
+ * Status Register bit description. Used by flash devices that don't
+ * support DQ polling (Eg.: HyperFlash)
+ */
+#define CFI_SR_DRB		BIT(7)
+#define CFI_SR_ESB		BIT(5)
+#define CFI_SR_PSB		BIT(4)
+#define CFI_SR_WBASB		BIT(3)
+#define CFI_SR_SLSB		BIT(1)
+
 static int cfi_amdstd_read (struct mtd_info *, loff_t, size_t, size_t *, u_char *);
 static int cfi_amdstd_write_words(struct mtd_info *, loff_t, size_t, size_t *, const u_char *);
 static int cfi_amdstd_write_buffers(struct mtd_info *, loff_t, size_t, size_t *, const u_char *);
@@ -97,6 +107,48 @@ static struct mtd_chip_driver cfi_amdstd_chipdrv = {
 	.module		= THIS_MODULE
 };
 
+/*
+ * Use status register to poll for Erase/write completion when DQ is not
+ * supported. This is indicated by Bit[1:0] of SoftwareFeatures field in
+ * CFI Primary Vendor-Specific Extended Query table 1.5
+ */
+static int cfi_use_status_reg(struct cfi_private *cfi)
+{
+	struct cfi_pri_amdstd *extp = cfi->cmdset_priv;
+
+	return (extp->MinorVersion >= '5') &&
+		(extp->SoftwareFeatures & 0x3) == 0x1;
+}
+
+static void cfi_check_err_status(struct map_info *map, unsigned long adr)
+{
+	struct cfi_private *cfi = map->fldrv_priv;
+	map_word status;
+
+	if (!cfi_use_status_reg(cfi))
+		return;
+
+	cfi_send_gen_cmd(0x70, cfi->addr_unlock1, 0, map, cfi,
+			 cfi->device_type, NULL);
+	status = map_read(map, adr);
+
+	if (map_word_bitsset(map, status, CMD(0x3a))) {
+		unsigned long chipstatus = MERGESTATUS(status);
+
+		if (chipstatus & CFI_SR_ESB)
+			pr_err("%s erase operation failed, status %lx\n",
+			       map->name, chipstatus);
+		if (chipstatus & CFI_SR_PSB)
+			pr_err("%s program operation failed, status %lx\n",
+			       map->name, chipstatus);
+		if (chipstatus & CFI_SR_WBASB)
+			pr_err("%s buffer program command aborted, status %lx\n",
+			       map->name, chipstatus);
+		if (chipstatus & CFI_SR_SLSB)
+			pr_err("%s sector write protected, status %lx\n",
+			       map->name, chipstatus);
+	}
+}
 
 /* #define DEBUG_CFI_FEATURES */
 
@@ -744,8 +796,22 @@ static struct mtd_info *cfi_amdstd_setup(struct mtd_info *mtd)
  */
 static int __xipram chip_ready(struct map_info *map, unsigned long addr)
 {
+	struct cfi_private *cfi = map->fldrv_priv;
 	map_word d, t;
 
+	if (cfi_use_status_reg(cfi)) {
+		map_word ready = CMD(CFI_SR_DRB);
+		/*
+		 * For chips that support status register, check device
+		 * ready bit
+		 */
+		cfi_send_gen_cmd(0x70, cfi->addr_unlock1, 0, map, cfi,
+				 cfi->device_type, NULL);
+		d = map_read(map, addr);
+
+		return map_word_andequal(map, d, ready, ready);
+	}
+
 	d = map_read(map, addr);
 	t = map_read(map, addr);
 
@@ -769,8 +835,27 @@ static int __xipram chip_ready(struct map_info *map, unsigned long addr)
  */
 static int __xipram chip_good(struct map_info *map, unsigned long addr, map_word expected)
 {
+	struct cfi_private *cfi = map->fldrv_priv;
 	map_word oldd, curd;
 
+	if (cfi_use_status_reg(cfi)) {
+		map_word ready = CMD(CFI_SR_DRB);
+		map_word err = CMD(CFI_SR_PSB | CFI_SR_ESB);
+		/*
+		 * For chips that support status register, check device
+		 * ready bit and Erase/Program status bit to know if
+		 * operation succeeded.
+		 */
+		cfi_send_gen_cmd(0x70, cfi->addr_unlock1, 0, map, cfi,
+				 cfi->device_type, NULL);
+		curd = map_read(map, addr);
+
+		if (map_word_andequal(map, curd, ready, ready))
+			return !map_word_bitsset(map, curd, err);
+
+		return 0;
+	}
+
 	oldd = map_read(map, addr);
 	curd = map_read(map, addr);
 
@@ -1643,6 +1728,7 @@ static int __xipram do_write_oneword(struct map_info *map, struct flchip *chip,
 	/* Did we succeed? */
 	if (!chip_good(map, adr, datum)) {
 		/* reset on all failures. */
+		cfi_check_err_status(map, adr);
 		map_write(map, CMD(0xF0), chip->start);
 		/* FIXME - should have reset delay before continuing */
 
@@ -1900,6 +1986,7 @@ static int __xipram do_write_buffer(struct map_info *map, struct flchip *chip,
 	 * See e.g.
 	 * http://www.spansion.com/Support/Application%20Notes/MirrorBit_Write_Buffer_Prog_Page_Buffer_Read_AN.pdf
 	 */
+	cfi_check_err_status(map, adr);
 	cfi_send_gen_cmd(0xAA, cfi->addr_unlock1, chip->start, map, cfi,
 			 cfi->device_type, NULL);
 	cfi_send_gen_cmd(0x55, cfi->addr_unlock2, chip->start, map, cfi,
@@ -2106,6 +2193,7 @@ static int do_panic_write_oneword(struct map_info *map, struct flchip *chip,
 
 	if (!chip_good(map, adr, datum)) {
 		/* reset on all failures. */
+		cfi_check_err_status(map, adr);
 		map_write(map, CMD(0xF0), chip->start);
 		/* FIXME - should have reset delay before continuing */
 
@@ -2315,6 +2403,7 @@ static int __xipram do_erase_chip(struct map_info *map, struct flchip *chip)
 	/* Did we succeed? */
 	if (ret) {
 		/* reset on all failures. */
+		cfi_check_err_status(map, adr);
 		map_write(map, CMD(0xF0), chip->start);
 		/* FIXME - should have reset delay before continuing */
 
@@ -2411,6 +2500,7 @@ static int __xipram do_erase_oneblock(struct map_info *map, struct flchip *chip,
 	/* Did we succeed? */
 	if (ret) {
 		/* reset on all failures. */
+		cfi_check_err_status(map, adr);
 		map_write(map, CMD(0xF0), chip->start);
 		/* FIXME - should have reset delay before continuing */
 
diff --git a/include/linux/mtd/cfi.h b/include/linux/mtd/cfi.h
index cbf77168658c..92ac82ac2329 100644
--- a/include/linux/mtd/cfi.h
+++ b/include/linux/mtd/cfi.h
@@ -233,6 +233,11 @@ struct cfi_pri_amdstd {
 	uint8_t  VppMin;
 	uint8_t  VppMax;
 	uint8_t  TopBottom;
+	/* Below field are added from version 1.5 */
+	uint8_t  ProgramSuspend;
+	uint8_t  UnlockBypass;
+	uint8_t  SecureSiliconSector;
+	uint8_t  SoftwareFeatures;
 } __packed;
 
 /* Vendor-Specific PRI for Atmel chips (command set 0x0002) */
-- 
2.21.0

[PATCH v3 2/5] dt-bindings: mtd: Add binding documentation for HyperFlash

[Vignesh Raghavendra]

Add DT binding documentation for HyperFlash devices.

Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
---
 .../devicetree/bindings/mtd/cypress,hyperflash.txt          | 6 ++++++
 1 file changed, 6 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mtd/cypress,hyperflash.txt

diff --git a/Documentation/devicetree/bindings/mtd/cypress,hyperflash.txt b/Documentation/devicetree/bindings/mtd/cypress,hyperflash.txt
new file mode 100644
index 000000000000..7fb7d82bb042
--- /dev/null
+++ b/Documentation/devicetree/bindings/mtd/cypress,hyperflash.txt
@@ -0,0 +1,6 @@
+Bindings for HyperFlash NOR flash chips compliant with Cypress HyperBus
+specification and supports Cypress CFI specification 1.5 command set.
+
+Required properties:
+- compatible : "cypress,hyperflash", "cfi-flash" for HyperFlash NOR chips
+- reg : Address where flash's memory mapped space
-- 
2.21.0

[PATCH v3 3/5] mtd: Add support for HyperBus memory devices

[Vignesh Raghavendra]

Cypress' HyperBus is Low Signal Count, High Performance Double Data Rate
Bus interface between a host system master and one or more slave
interfaces. HyperBus is used to connect microprocessor, microcontroller,
or ASIC devices with random access NOR flash memory (called HyperFlash)
or self refresh DRAM (called HyperRAM).

Its a 8-bit data bus (DQ[7:0]) with  Read-Write Data Strobe (RWDS)
signal and either Single-ended clock(3.0V parts) or Differential clock
(1.8V parts). It uses ChipSelect lines to select b/w multiple slaves.
At bus level, it follows a separate protocol described in HyperBus
specification[1].

HyperFlash follows CFI AMD/Fujitsu Extended Command Set (0x0002) similar
to that of existing parallel NORs. Since HyperBus is x8 DDR bus,
its equivalent to x16 parallel NOR flash wrt bits per clock cycle. But
HyperBus operates at >166MHz frequencies.
HyperRAM provides direct random read/write access to flash memory
array.

But, HyperBus memory controllers seem to abstract implementation details
and expose a simple MMIO interface to access connected flash.

Add support for registering HyperFlash devices with MTD framework. MTD
maps framework along with CFI chip support framework are used to support
communicating with flash.

Framework is modelled along the lines of spi-nor framework. HyperBus
memory controller (HBMC) drivers calls hyperbus_register_device() to
register a single HyperFlash device. HyperFlash core parses MMIO access
information from DT, sets up the map_info struct, probes CFI flash and
registers it with MTD framework.

Some HBMC masters need calibration/training sequence[3] to be carried
out, in order for DLL inside the controller to lock, by reading a known
string/pattern. This is done by repeatedly reading CFI Query
Identification String. Calibration needs to be done before trying to detect
flash as part of CFI flash probe.

HyperRAM is not supported at the moment.

HyperBus specification can be found at[1]
HyperFlash datasheet can be found at[2]

[1] https://www.cypress.com/file/213356/download
[2] https://www.cypress.com/file/213346/download
[3] http://www.ti.com/lit/ug/spruid7b/spruid7b.pdf
    Table 12-5741. HyperFlash Access Sequence

Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
---
 MAINTAINERS                          |   7 +
 drivers/mtd/Kconfig                  |   2 +
 drivers/mtd/Makefile                 |   1 +
 drivers/mtd/hyperbus/Kconfig         |  11 ++
 drivers/mtd/hyperbus/Makefile        |   3 +
 drivers/mtd/hyperbus/hyperbus-core.c | 192 +++++++++++++++++++++++++++
 include/linux/mtd/hyperbus.h         |  91 +++++++++++++
 7 files changed, 307 insertions(+)
 create mode 100644 drivers/mtd/hyperbus/Kconfig
 create mode 100644 drivers/mtd/hyperbus/Makefile
 create mode 100644 drivers/mtd/hyperbus/hyperbus-core.c
 create mode 100644 include/linux/mtd/hyperbus.h

diff --git a/MAINTAINERS b/MAINTAINERS
index d60b67e58ea8..7aa1b3454a89 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -7243,6 +7243,13 @@ F:	include/uapi/linux/hyperv.h
 F:	tools/hv/
 F:	Documentation/ABI/stable/sysfs-bus-vmbus
 
+HYPERBUS SUPPORT
+M:	Vignesh Raghavendra <vigneshr@ti.com>
+S:	Supported
+F:	drivers/mtd/hyperbus/
+F:	include/linux/mtd/hyperbus.h
+F:	Documentation/devicetree/bindings/mtd/cypress,hyperbus.txt
+
 HYPERVISOR VIRTUAL CONSOLE DRIVER
 L:	linuxppc-dev@lists.ozlabs.org
 S:	Odd Fixes
diff --git a/drivers/mtd/Kconfig b/drivers/mtd/Kconfig
index aa5a27fdfdd1..03315fb9c895 100644
--- a/drivers/mtd/Kconfig
+++ b/drivers/mtd/Kconfig
@@ -289,4 +289,6 @@ source "drivers/mtd/spi-nor/Kconfig"
 
 source "drivers/mtd/ubi/Kconfig"
 
+source "drivers/mtd/hyperbus/Kconfig"
+
 endif # MTD
diff --git a/drivers/mtd/Makefile b/drivers/mtd/Makefile
index 58fc327a5276..04c154906631 100644
--- a/drivers/mtd/Makefile
+++ b/drivers/mtd/Makefile
@@ -35,3 +35,4 @@ obj-y		+= chips/ lpddr/ maps/ devices/ nand/ tests/
 
 obj-$(CONFIG_MTD_SPI_NOR)	+= spi-nor/
 obj-$(CONFIG_MTD_UBI)		+= ubi/
+obj-$(CONFIG_MTD_HYPERBUS)	+= hyperbus/
diff --git a/drivers/mtd/hyperbus/Kconfig b/drivers/mtd/hyperbus/Kconfig
new file mode 100644
index 000000000000..98147e28caa0
--- /dev/null
+++ b/drivers/mtd/hyperbus/Kconfig
@@ -0,0 +1,11 @@
+menuconfig MTD_HYPERBUS
+	tristate "HyperBus support"
+	select MTD_CFI
+	select MTD_MAP_BANK_WIDTH_2
+	select MTD_CFI_AMDSTD
+	select MTD_COMPLEX_MAPPINGS
+	help
+	  This is the framework for the HyperBus which can be used by
+	  the HyperBus Controller driver to communicate with
+	  HyperFlash. See Cypress HyperBus specification for more
+	  details
diff --git a/drivers/mtd/hyperbus/Makefile b/drivers/mtd/hyperbus/Makefile
new file mode 100644
index 000000000000..ca61dedd730d
--- /dev/null
+++ b/drivers/mtd/hyperbus/Makefile
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0
+
+obj-$(CONFIG_MTD_HYPERBUS)	+= hyperbus-core.o
diff --git a/drivers/mtd/hyperbus/hyperbus-core.c b/drivers/mtd/hyperbus/hyperbus-core.c
new file mode 100644
index 000000000000..49aeb59742c6
--- /dev/null
+++ b/drivers/mtd/hyperbus/hyperbus-core.c
@@ -0,0 +1,192 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// Copyright (C) 2019 Texas Instruments Incorporated - http://www.ti.com/
+// Author: Vignesh Raghavendra <vigneshr@ti.com>
+
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mtd/hyperbus.h>
+#include <linux/mtd/map.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/cfi.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/types.h>
+
+#define HYPERBUS_CALIB_COUNT 25
+
+static struct hyperbus_device *map_to_hbdev(struct map_info *map)
+{
+	return container_of(map, struct hyperbus_device, map);
+}
+
+static map_word hyperbus_read16(struct map_info *map, unsigned long addr)
+{
+	struct hyperbus_device *hbdev = map_to_hbdev(map);
+	struct hyperbus_ctlr *ctlr = hbdev->ctlr;
+	map_word read_data;
+
+	read_data.x[0] = ctlr->ops->read16(hbdev, addr);
+
+	return read_data;
+}
+
+static void hyperbus_write16(struct map_info *map, map_word d,
+			     unsigned long addr)
+{
+	struct hyperbus_device *hbdev = map_to_hbdev(map);
+	struct hyperbus_ctlr *ctlr = hbdev->ctlr;
+
+	ctlr->ops->write16(hbdev, addr, d.x[0]);
+}
+
+static void hyperbus_copy_from(struct map_info *map, void *to,
+			       unsigned long from, ssize_t len)
+{
+	struct hyperbus_device *hbdev = map_to_hbdev(map);
+	struct hyperbus_ctlr *ctlr = hbdev->ctlr;
+
+	ctlr->ops->copy_from(hbdev, to, from, len);
+}
+
+static void hyperbus_copy_to(struct map_info *map, unsigned long to,
+			     const void *from, ssize_t len)
+{
+	struct hyperbus_device *hbdev = map_to_hbdev(map);
+	struct hyperbus_ctlr *ctlr = hbdev->ctlr;
+
+	ctlr->ops->copy_to(hbdev, to, from, len);
+}
+
+/* Default calibration routine for use by HyperBus controller.
+ * Controller is calibrated by repeatedly reading known pattern ("QRY"
+ * string from CFI space)
+ * Lets ensure "QRY" string is read correctly at least 5 times to ensure
+ * stability of the DLL lock.
+ */
+int hyperbus_calibrate(struct hyperbus_device *hbdev)
+{
+	struct map_info *map = &hbdev->map;
+	struct cfi_private cfi;
+	int count = HYPERBUS_CALIB_COUNT;
+	int pass_count = 0;
+	int ret;
+
+	cfi.interleave = 1;
+	cfi.device_type = CFI_DEVICETYPE_X16;
+	cfi_send_gen_cmd(0xF0, 0, 0, map, &cfi, cfi.device_type, NULL);
+	cfi_send_gen_cmd(0x98, 0x55, 0, map, &cfi, cfi.device_type, NULL);
+
+	while (count--) {
+		cfi_qry_present(map, 0, &cfi);
+		ret = cfi_qry_present(map, 0, &cfi);
+		if (ret)
+			pass_count++;
+		else
+			pass_count = 0;
+		if (pass_count == 5)
+			break;
+	}
+
+	cfi_qry_mode_off(0, map, &cfi);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(hyperbus_calibrate);
+
+int hyperbus_register_device(struct hyperbus_device *hbdev)
+{
+	const struct hyperbus_ops *ops;
+	struct hyperbus_ctlr *ctlr;
+	struct device_node *np;
+	struct map_info *map;
+	struct resource res;
+	struct device *dev;
+	int ret;
+
+	if (!hbdev || !hbdev->np || !hbdev->ctlr || !hbdev->ctlr->dev) {
+		pr_err("hyperbus: please fill all the necessary fields!\n");
+		return -EINVAL;
+	}
+
+	np = hbdev->np;
+	ctlr = hbdev->ctlr;
+	if (!of_device_is_compatible(np, "cypress,hyperflash"))
+		return -ENODEV;
+
+	hbdev->memtype = HYPERFLASH;
+
+	if (of_address_to_resource(np, 0, &res))
+		return -EINVAL;
+
+	dev = ctlr->dev;
+	map = &hbdev->map;
+	map->size = resource_size(&res);
+	map->virt = devm_ioremap_resource(dev, &res);
+	if (IS_ERR(map->virt))
+		return PTR_ERR(map->virt);
+
+	map->name = dev_name(dev);
+	map->bankwidth = 2;
+	map->device_node = np;
+
+	simple_map_init(map);
+	ops = ctlr->ops;
+	if (ops) {
+		if (ops->read16)
+			map->read = hyperbus_read16;
+		if (ops->write16)
+			map->write = hyperbus_write16;
+		if (ops->copy_to)
+			map->copy_to = hyperbus_copy_to;
+		if (ops->copy_from)
+			map->copy_from = hyperbus_copy_from;
+
+		if (ops->calibrate && !ctlr->calibrated) {
+			ret = ops->calibrate(hbdev);
+			if (!ret) {
+				dev_err(dev, "Calibration failed\n");
+				return -ENODEV;
+			}
+			ctlr->calibrated = true;
+		}
+	}
+
+	hbdev->mtd = do_map_probe("cfi_probe", map);
+	if (!hbdev->mtd) {
+		dev_err(dev, "probing of hyperbus device failed\n");
+		return -ENODEV;
+	}
+
+	hbdev->mtd->dev.parent = dev;
+	mtd_set_of_node(hbdev->mtd, np);
+
+	ret = mtd_device_register(hbdev->mtd, NULL, 0);
+	if (ret) {
+		dev_err(dev, "failed to register mtd device\n");
+		map_destroy(hbdev->mtd);
+		return ret;
+	}
+	hbdev->registered = true;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(hyperbus_register_device);
+
+int hyperbus_unregister_device(struct hyperbus_device *hbdev)
+{
+	int ret = 0;
+
+	if (hbdev && hbdev->mtd && hbdev->registered) {
+		ret = mtd_device_unregister(hbdev->mtd);
+		map_destroy(hbdev->mtd);
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(hyperbus_unregister_device);
+
+MODULE_DESCRIPTION("HyperBus Framework");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Vignesh Raghavendra <vigneshr@ti.com>");
diff --git a/include/linux/mtd/hyperbus.h b/include/linux/mtd/hyperbus.h
new file mode 100644
index 000000000000..19340cc56aa4
--- /dev/null
+++ b/include/linux/mtd/hyperbus.h
@@ -0,0 +1,91 @@
+/* SPDX-License-Identifier: GPL-2.0
+ *
+ * Copyright (C) 2019 Texas Instruments Incorporated - http://www.ti.com/
+ */
+
+#ifndef __LINUX_MTD_HYPERBUS_H__
+#define __LINUX_MTD_HYPERBUS_H__
+
+#include <linux/mtd/map.h>
+
+enum hyperbus_memtype {
+	HYPERFLASH,
+	HYPERRAM,
+};
+
+/**
+ * struct hyperbus_device - struct representing HyperBus slave device
+ * @map: map_info struct for accessing MMIO HyperBus flash memory
+ * @np:	pointer to HyperBus slave device node
+ * @mtd: pointer to MTD struct
+ * @ctlr: pointer to HyperBus controller struct
+ * @memtype: type of memory device: HyperFlash or HyperRAM
+ * @registered: flag to indicate whether device is registered with MTD core
+ */
+
+struct hyperbus_device {
+	struct map_info map;
+	struct device_node *np;
+	struct mtd_info *mtd;
+	struct hyperbus_ctlr *ctlr;
+	enum hyperbus_memtype memtype;
+	bool registered;
+};
+
+/**
+ * struct hyperbus_ops - struct representing custom HyperBus operations
+ * @read16: read 16 bit of data, usually from register/ID-CFI space
+ * @write16: write 16 bit of data, usually to register/ID-CFI space
+ * @copy_from: copy data from flash memory
+ * @copy_to: copy data to flash memory
+ * @calibrate: calibrate HyperBus controller
+ */
+
+struct hyperbus_ops {
+	u16 (*read16)(struct hyperbus_device *hbdev, unsigned long addr);
+	void (*write16)(struct hyperbus_device *hbdev,
+			unsigned long addr, u16 val);
+	void (*copy_from)(struct hyperbus_device *hbdev, void *to,
+			  unsigned long from, ssize_t len);
+	void (*copy_to)(struct hyperbus_device *dev, unsigned long to,
+			const void *from, ssize_t len);
+	int (*calibrate)(struct hyperbus_device *dev);
+};
+
+/**
+ * struct hyperbus_ctlr - struct representing HyperBus controller
+ * @calibrated: flag to indicate ctlr calibration sequence is complete
+ * @ops: HyperBus controller ops
+ */
+struct hyperbus_ctlr {
+	struct device *dev;
+	bool calibrated;
+
+	const struct hyperbus_ops *ops;
+};
+
+/**
+ * hyperbus_calibrate - default calibration routine for use by HyperBus ctlr.
+ * @hbdev: hyperbus_device to be used for calibration
+ *
+ * Return: 0 for success, others for failure.
+ */
+int hyperbus_calibrate(struct hyperbus_device *hbdev);
+
+/**
+ * hyperbus_register_device - probe and register a HyperBus slave memory device
+ * @hbdev: hyperbus_device struct with dev, np and ctlr field populated
+ *
+ * Return: 0 for success, others for failure.
+ */
+int hyperbus_register_device(struct hyperbus_device *hbdev);
+
+/**
+ * hb_unregister_device - deregister HyperBus slave memory device
+ * @hbdev: hyperbus_device to be unregistered
+ *
+ * Return: 0 for success, others for failure.
+ */
+int hyperbus_unregister_device(struct hyperbus_device *hbdev);
+
+#endif /* __LINUX_MTD_HYPERBUS_H__ */
-- 
2.21.0

[PATCH v3 4/5] dt-bindings: mtd: Add bindings for TI's AM654 HyperBus memory controller

[Vignesh Raghavendra]

Add binding documentation for TI's HyperBus memory controller present on
AM654 SoC.

Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
---
 .../devicetree/bindings/mtd/ti,am654-hbmc.txt | 31 +++++++++++++++++++
 MAINTAINERS                                   |  1 +
 2 files changed, 32 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mtd/ti,am654-hbmc.txt

diff --git a/Documentation/devicetree/bindings/mtd/ti,am654-hbmc.txt b/Documentation/devicetree/bindings/mtd/ti,am654-hbmc.txt
new file mode 100644
index 000000000000..00888482df25
--- /dev/null
+++ b/Documentation/devicetree/bindings/mtd/ti,am654-hbmc.txt
@@ -0,0 +1,31 @@
+Bindings for HyperBus Memory Controller (HBMC) on TI's K3 family of SoCs
+
+Required properties:
+- compatible : "ti,am654-hbmc" for AM654 SoC
+- reg : Two entries:
+	First entry pointed to the register space of HBMC controller
+	Second entry pointing to the memory map region dedicated for
+	MMIO access to attached flash devices
+- ranges : Address range allocated for each chipselect in the MMIO space
+
+Optional properties:
+- mux-controls: phandle to the multiplexer that controls selection of
+		HBMC vs OSPI. Mux state of 1 indicates HBMC is selected.
+
+Example:
+	hbmc: hbmc@47034000 {
+		compatible = "ti,am654-hbmc";
+		reg = <0x0 0x47034000 0x0 0x100>,
+			<0x5 0x00000000 0x1 0x0000000>;
+		power-domains = <&k3_pds 55>;
+		#address-cells = <1>;
+		#size-cells = <1>;
+		ranges = <0x0 0x5 0x00000000 0x4000000>, /* CS0 - 64MB */
+			 <0x1 0x5 0x04000000 0x4000000>; /* CS1 - 64MB
+
+		/* Slave flash node */
+		flash@0{
+			compatible = "cypress,hyperflash";
+			reg = <0x0 0x4000000>;
+		};
+	};
diff --git a/MAINTAINERS b/MAINTAINERS
index 7aa1b3454a89..07455035fca9 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -7249,6 +7249,7 @@ S:	Supported
 F:	drivers/mtd/hyperbus/
 F:	include/linux/mtd/hyperbus.h
 F:	Documentation/devicetree/bindings/mtd/cypress,hyperbus.txt
+F:	Documentation/devicetree/bindings/mtd/ti,am654-hbmc.txt
 
 HYPERVISOR VIRTUAL CONSOLE DRIVER
 L:	linuxppc-dev@lists.ozlabs.org
-- 
2.21.0

[PATCH v3 5/5] mtd: hyperbus: Add driver for TI's HyperBus memory controller

[Vignesh Raghavendra]

Add driver for HyperBus memory controller on TI's AM654 SoC. Programming
IP is pretty simple and provides direct memory mapped access to
connected Flash devices.

Add basic support for the IP without DMA. Second chipSelect is not
supported for now.

Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
---
 drivers/mtd/hyperbus/Kconfig      |  12 ++++
 drivers/mtd/hyperbus/Makefile     |   1 +
 drivers/mtd/hyperbus/hbmc-am654.c | 115 ++++++++++++++++++++++++++++++
 3 files changed, 128 insertions(+)
 create mode 100644 drivers/mtd/hyperbus/hbmc-am654.c

diff --git a/drivers/mtd/hyperbus/Kconfig b/drivers/mtd/hyperbus/Kconfig
index 98147e28caa0..cff6bbd226f5 100644
--- a/drivers/mtd/hyperbus/Kconfig
+++ b/drivers/mtd/hyperbus/Kconfig
@@ -9,3 +9,15 @@ menuconfig MTD_HYPERBUS
 	  the HyperBus Controller driver to communicate with
 	  HyperFlash. See Cypress HyperBus specification for more
 	  details
+
+if MTD_HYPERBUS
+
+config HBMC_AM654
+	tristate "HyperBus controller driver for AM65x SoC"
+	select MULTIPLEXER
+	select MUX_MMIO
+	help
+	 This is the driver for HyperBus controller on TI's AM65x and
+	 other SoCs
+
+endif # MTD_HYPERBUS
diff --git a/drivers/mtd/hyperbus/Makefile b/drivers/mtd/hyperbus/Makefile
index ca61dedd730d..8a936e066f48 100644
--- a/drivers/mtd/hyperbus/Makefile
+++ b/drivers/mtd/hyperbus/Makefile
@@ -1,3 +1,4 @@
 # SPDX-License-Identifier: GPL-2.0
 
 obj-$(CONFIG_MTD_HYPERBUS)	+= hyperbus-core.o
+obj-$(CONFIG_HBMC_AM654)	+= hbmc-am654.o
diff --git a/drivers/mtd/hyperbus/hbmc-am654.c b/drivers/mtd/hyperbus/hbmc-am654.c
new file mode 100644
index 000000000000..f458d7226df9
--- /dev/null
+++ b/drivers/mtd/hyperbus/hbmc-am654.c
@@ -0,0 +1,115 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// Copyright (C) 2019 Texas Instruments Incorporated - http://www.ti.com/
+// Author: Vignesh Raghavendra <vigneshr@ti.com>
+
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mtd/hyperbus.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mux/consumer.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/types.h>
+
+struct am654_hbmc_priv {
+	struct hyperbus_ctlr ctlr;
+	struct hyperbus_device hbdev;
+	void __iomem	*regbase;
+};
+
+static const struct hyperbus_ops am654_hbmc_ops = {
+	.calibrate = hyperbus_calibrate,
+};
+
+static int am654_hbmc_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct am654_hbmc_priv *priv;
+	int ret;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, priv);
+
+	priv->regbase = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(priv->regbase))
+		return PTR_ERR(priv->regbase);
+
+	if (of_property_read_bool(dev->of_node, "mux-controls")) {
+		struct mux_control *control = devm_mux_control_get(dev, NULL);
+
+		if (IS_ERR(control))
+			return PTR_ERR(control);
+
+		ret = mux_control_select(control, 1);
+		if (ret) {
+			dev_err(dev, "Failed to select HBMC mux\n");
+			return ret;
+		}
+	}
+
+	pm_runtime_enable(dev);
+	ret = pm_runtime_get_sync(dev);
+	if (ret < 0) {
+		pm_runtime_put_noidle(dev);
+		goto disable_pm;
+	}
+
+	priv->ctlr.dev = dev;
+	priv->ctlr.ops = &am654_hbmc_ops;
+	priv->hbdev.ctlr = &priv->ctlr;
+	priv->hbdev.np = of_get_next_child(dev->of_node, NULL);
+	ret = hyperbus_register_device(&priv->hbdev);
+	if (ret) {
+		dev_err(dev, "failed to register controller\n");
+		pm_runtime_put_sync(&pdev->dev);
+		goto disable_pm;
+	}
+
+	return 0;
+disable_pm:
+	pm_runtime_disable(dev);
+	return ret;
+}
+
+static int am654_hbmc_remove(struct platform_device *pdev)
+{
+	struct am654_hbmc_priv *priv = platform_get_drvdata(pdev);
+	int ret;
+
+	ret = hyperbus_unregister_device(&priv->hbdev);
+	pm_runtime_put_sync(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
+
+	return ret;
+}
+
+static const struct of_device_id am654_hbmc_dt_ids[] = {
+	{
+		.compatible = "ti,am654-hbmc",
+	},
+	{ /* end of table */ }
+};
+
+MODULE_DEVICE_TABLE(of, am654_hbmc_dt_ids);
+
+static struct platform_driver am654_hbmc_platform_driver = {
+	.probe = am654_hbmc_probe,
+	.remove = am654_hbmc_remove,
+	.driver = {
+		.name = "hbmc-am654",
+		.of_match_table = am654_hbmc_dt_ids,
+	},
+};
+
+module_platform_driver(am654_hbmc_platform_driver);
+
+MODULE_DESCRIPTION("HBMC driver for AM654 SoC");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:hbmc-am654");
+MODULE_AUTHOR("Vignesh Raghavendra <vigneshr@ti.com>");
-- 
2.21.0

Re: [PATCH v3 3/5] mtd: Add support for HyperBus memory devices

[Sergei Shtylyov]

Hello!

On 04/12/2019 12:29 PM, Vignesh Raghavendra wrote:

> Cypress' HyperBus is Low Signal Count, High Performance Double Data Rate
> Bus interface between a host system master and one or more slave
> interfaces. HyperBus is used to connect microprocessor, microcontroller,
> or ASIC devices with random access NOR flash memory (called HyperFlash)
> or self refresh DRAM (called HyperRAM).
> 
> Its a 8-bit data bus (DQ[7:0]) with  Read-Write Data Strobe (RWDS)
> signal and either Single-ended clock(3.0V parts) or Differential clock
> (1.8V parts). It uses ChipSelect lines to select b/w multiple slaves.
> At bus level, it follows a separate protocol described in HyperBus
> specification[1].
> 
> HyperFlash follows CFI AMD/Fujitsu Extended Command Set (0x0002) similar
> to that of existing parallel NORs. Since HyperBus is x8 DDR bus,
> its equivalent to x16 parallel NOR flash wrt bits per clock cycle. But
> HyperBus operates at >166MHz frequencies.
> HyperRAM provides direct random read/write access to flash memory
> array.
> 
> But, HyperBus memory controllers seem to abstract implementation details
> and expose a simple MMIO interface to access connected flash.
> 
> Add support for registering HyperFlash devices with MTD framework. MTD
> maps framework along with CFI chip support framework are used to support
> communicating with flash.
> 
> Framework is modelled along the lines of spi-nor framework. HyperBus
> memory controller (HBMC) drivers calls hyperbus_register_device() to
> register a single HyperFlash device. HyperFlash core parses MMIO access
> information from DT, sets up the map_info struct, probes CFI flash and
> registers it with MTD framework.
> 
> Some HBMC masters need calibration/training sequence[3] to be carried
> out, in order for DLL inside the controller to lock, by reading a known
> string/pattern. This is done by repeatedly reading CFI Query
> Identification String. Calibration needs to be done before trying to detect
> flash as part of CFI flash probe.
> 
> HyperRAM is not supported at the moment.
> 
> HyperBus specification can be found at[1]
> HyperFlash datasheet can be found at[2]
> 
> [1] https://www.cypress.com/file/213356/download
> [2] https://www.cypress.com/file/213346/download
> [3] http://www.ti.com/lit/ug/spruid7b/spruid7b.pdf
>     Table 12-5741. HyperFlash Access Sequence
> 
> Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
[...]
> diff --git a/drivers/mtd/hyperbus/Kconfig b/drivers/mtd/hyperbus/Kconfig
> new file mode 100644
> index 000000000000..98147e28caa0
> --- /dev/null
> +++ b/drivers/mtd/hyperbus/Kconfig
> @@ -0,0 +1,11 @@
> +menuconfig MTD_HYPERBUS
> +	tristate "HyperBus support"
> +	select MTD_CFI
> +	select MTD_MAP_BANK_WIDTH_2
> +	select MTD_CFI_AMDSTD
> +	select MTD_COMPLEX_MAPPINGS
> +	help
> +	  This is the framework for the HyperBus which can be used by
> +	  the HyperBus Controller driver to communicate with
> +	  HyperFlash. See Cypress HyperBus specification for more
> +	  details
> diff --git a/drivers/mtd/hyperbus/Makefile b/drivers/mtd/hyperbus/Makefile
> new file mode 100644
> index 000000000000..ca61dedd730d
> --- /dev/null
> +++ b/drivers/mtd/hyperbus/Makefile
> @@ -0,0 +1,3 @@
> +# SPDX-License-Identifier: GPL-2.0
> +
> +obj-$(CONFIG_MTD_HYPERBUS)	+= hyperbus-core.o
> diff --git a/drivers/mtd/hyperbus/hyperbus-core.c b/drivers/mtd/hyperbus/hyperbus-core.c
> new file mode 100644
> index 000000000000..49aeb59742c6
> --- /dev/null
> +++ b/drivers/mtd/hyperbus/hyperbus-core.c
> @@ -0,0 +1,192 @@
> +// SPDX-License-Identifier: GPL-2.0
> +//
> +// Copyright (C) 2019 Texas Instruments Incorporated - http://www.ti.com/
> +// Author: Vignesh Raghavendra <vigneshr@ti.com>
[...]
> +/* Default calibration routine for use by HyperBus controller.
> + * Controller is calibrated by repeatedly reading known pattern ("QRY"
> + * string from CFI space)
> + * Lets ensure "QRY" string is read correctly at least 5 times to ensure
> + * stability of the DLL lock.
> + */
> +int hyperbus_calibrate(struct hyperbus_device *hbdev)
> +{
> +	struct map_info *map = &hbdev->map;
> +	struct cfi_private cfi;
> +	int count = HYPERBUS_CALIB_COUNT;
> +	int pass_count = 0;
> +	int ret;
> +
> +	cfi.interleave = 1;
> +	cfi.device_type = CFI_DEVICETYPE_X16;
> +	cfi_send_gen_cmd(0xF0, 0, 0, map, &cfi, cfi.device_type, NULL);
> +	cfi_send_gen_cmd(0x98, 0x55, 0, map, &cfi, cfi.device_type, NULL);
> +
> +	while (count--) {
> +		cfi_qry_present(map, 0, &cfi);
> +		ret = cfi_qry_present(map, 0, &cfi);

   Why call it twice in a row?

> +		if (ret)
> +			pass_count++;
> +		else
> +			pass_count = 0;
> +		if (pass_count == 5)
> +			break;
> +	}
> +
> +	cfi_qry_mode_off(0, map, &cfi);
> +
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(hyperbus_calibrate);
[...]
> diff --git a/include/linux/mtd/hyperbus.h b/include/linux/mtd/hyperbus.h
> new file mode 100644
> index 000000000000..19340cc56aa4
> --- /dev/null
> +++ b/include/linux/mtd/hyperbus.h
> @@ -0,0 +1,91 @@
[...]
> +/**
> + * hb_unregister_device - deregister HyperBus slave memory device

   You forgot to update the function name in the kernel-doc. :-)

> + * @hbdev: hyperbus_device to be unregistered
> + *
> + * Return: 0 for success, others for failure.
> + */
> +int hyperbus_unregister_device(struct hyperbus_device *hbdev);
> +
> +#endif /* __LINUX_MTD_HYPERBUS_H__ */

MBR, Sergei

Re: [PATCH v3 4/5] dt-bindings: mtd: Add bindings for TI's AM654 HyperBus memory controller

[Sergei Shtylyov]

On 04/12/2019 12:29 PM, Vignesh Raghavendra wrote:

> Add binding documentation for TI's HyperBus memory controller present on
> AM654 SoC.
> 
> Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
> ---
>  .../devicetree/bindings/mtd/ti,am654-hbmc.txt | 31 +++++++++++++++++++
>  MAINTAINERS                                   |  1 +
>  2 files changed, 32 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/mtd/ti,am654-hbmc.txt
> 
> diff --git a/Documentation/devicetree/bindings/mtd/ti,am654-hbmc.txt b/Documentation/devicetree/bindings/mtd/ti,am654-hbmc.txt
> new file mode 100644
> index 000000000000..00888482df25
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mtd/ti,am654-hbmc.txt
> @@ -0,0 +1,31 @@
[...]
> +Optional properties:
> +- mux-controls: phandle to the multiplexer that controls selection of
> +		HBMC vs OSPI. Mux state of 1 indicates HBMC is selected.

   I thought this is usually done with the help of drivers/pinctrl/..

> +
> +Example:
> +	hbmc: hbmc@47034000 {
> +		compatible = "ti,am654-hbmc";
> +		reg = <0x0 0x47034000 0x0 0x100>,
> +			<0x5 0x00000000 0x1 0x0000000>;
> +		power-domains = <&k3_pds 55>;
> +		#address-cells = <1>;
> +		#size-cells = <1>;
> +		ranges = <0x0 0x5 0x00000000 0x4000000>, /* CS0 - 64MB */
> +			 <0x1 0x5 0x04000000 0x4000000>; /* CS1 - 64MB
> +
> +		/* Slave flash node */
> +		flash@0{

   Need space before {.

> +			compatible = "cypress,hyperflash";
> +			reg = <0x0 0x4000000>;
> +		};
> +	};
[...]

MBR, Sergei

Re: [PATCH v3 4/5] dt-bindings: mtd: Add bindings for TI's AM654 HyperBus memory controller

[Vignesh Raghavendra]

On 14/04/19 11:25 PM, Sergei Shtylyov wrote:
> On 04/12/2019 12:29 PM, Vignesh Raghavendra wrote:
> 
>> Add binding documentation for TI's HyperBus memory controller present on
>> AM654 SoC.
>>
>> Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
>> ---
>>  .../devicetree/bindings/mtd/ti,am654-hbmc.txt | 31 +++++++++++++++++++
>>  MAINTAINERS                                   |  1 +
>>  2 files changed, 32 insertions(+)
>>  create mode 100644 Documentation/devicetree/bindings/mtd/ti,am654-hbmc.txt
>>
>> diff --git a/Documentation/devicetree/bindings/mtd/ti,am654-hbmc.txt b/Documentation/devicetree/bindings/mtd/ti,am654-hbmc.txt
>> new file mode 100644
>> index 000000000000..00888482df25
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/mtd/ti,am654-hbmc.txt
>> @@ -0,0 +1,31 @@
> [...]
>> +Optional properties:
>> +- mux-controls: phandle to the multiplexer that controls selection of
>> +		HBMC vs OSPI. Mux state of 1 indicates HBMC is selected.
> 
>    I thought this is usually done with the help of drivers/pinctrl/..
> 

This mux is internal to SoC and not at SoC pad level. Based on this bit
read/write requests at SoC interconnect is routed either to OSPI or
HBMC, hence mmio-mux is a good fit

OSPI and HBMC data pins are themselves at pad level which is handled by
pinctrl-single node.

>> +
>> +Example:
>> +	hbmc: hbmc@47034000 {
>> +		compatible = "ti,am654-hbmc";
>> +		reg = <0x0 0x47034000 0x0 0x100>,
>> +			<0x5 0x00000000 0x1 0x0000000>;
>> +		power-domains = <&k3_pds 55>;
>> +		#address-cells = <1>;
>> +		#size-cells = <1>;
>> +		ranges = <0x0 0x5 0x00000000 0x4000000>, /* CS0 - 64MB */
>> +			 <0x1 0x5 0x04000000 0x4000000>; /* CS1 - 64MB
>> +
>> +		/* Slave flash node */
>> +		flash@0{
> 
>    Need space before {.
> 

Will fix.

>> +			compatible = "cypress,hyperflash";
>> +			reg = <0x0 0x4000000>;
>> +		};
>> +	};
> [...]
> 
> MBR, Sergei
> 

-- 
Regards
Vignesh

Re: [PATCH v3 3/5] mtd: Add support for HyperBus memory devices

[Vignesh Raghavendra]

Hi,

On 14/04/19 11:21 PM, Sergei Shtylyov wrote:
> Hello!
> 
> On 04/12/2019 12:29 PM, Vignesh Raghavendra wrote:
> 
>> Cypress' HyperBus is Low Signal Count, High Performance Double Data Rate
>> Bus interface between a host system master and one or more slave
>> interfaces. HyperBus is used to connect microprocessor, microcontroller,
>> or ASIC devices with random access NOR flash memory (called HyperFlash)
>> or self refresh DRAM (called HyperRAM).
>>
>> Its a 8-bit data bus (DQ[7:0]) with  Read-Write Data Strobe (RWDS)
>> signal and either Single-ended clock(3.0V parts) or Differential clock
>> (1.8V parts). It uses ChipSelect lines to select b/w multiple slaves.
>> At bus level, it follows a separate protocol described in HyperBus
>> specification[1].
>>
>> HyperFlash follows CFI AMD/Fujitsu Extended Command Set (0x0002) similar
>> to that of existing parallel NORs. Since HyperBus is x8 DDR bus,
>> its equivalent to x16 parallel NOR flash wrt bits per clock cycle. But
>> HyperBus operates at >166MHz frequencies.
>> HyperRAM provides direct random read/write access to flash memory
>> array.
>>
>> But, HyperBus memory controllers seem to abstract implementation details
>> and expose a simple MMIO interface to access connected flash.
>>
>> Add support for registering HyperFlash devices with MTD framework. MTD
>> maps framework along with CFI chip support framework are used to support
>> communicating with flash.
>>
>> Framework is modelled along the lines of spi-nor framework. HyperBus
>> memory controller (HBMC) drivers calls hyperbus_register_device() to
>> register a single HyperFlash device. HyperFlash core parses MMIO access
>> information from DT, sets up the map_info struct, probes CFI flash and
>> registers it with MTD framework.
>>
>> Some HBMC masters need calibration/training sequence[3] to be carried
>> out, in order for DLL inside the controller to lock, by reading a known
>> string/pattern. This is done by repeatedly reading CFI Query
>> Identification String. Calibration needs to be done before trying to detect
>> flash as part of CFI flash probe.
>>
>> HyperRAM is not supported at the moment.
>>
>> HyperBus specification can be found at[1]
>> HyperFlash datasheet can be found at[2]
>>
>> [1] https://www.cypress.com/file/213356/download
>> [2] https://www.cypress.com/file/213346/download
>> [3] http://www.ti.com/lit/ug/spruid7b/spruid7b.pdf
>>     Table 12-5741. HyperFlash Access Sequence
>>
>> Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
> [...]
>> diff --git a/drivers/mtd/hyperbus/Kconfig b/drivers/mtd/hyperbus/Kconfig
>> new file mode 100644
>> index 000000000000..98147e28caa0
>> --- /dev/null
>> +++ b/drivers/mtd/hyperbus/Kconfig
>> @@ -0,0 +1,11 @@
>> +menuconfig MTD_HYPERBUS
>> +	tristate "HyperBus support"
>> +	select MTD_CFI
>> +	select MTD_MAP_BANK_WIDTH_2
>> +	select MTD_CFI_AMDSTD
>> +	select MTD_COMPLEX_MAPPINGS
>> +	help
>> +	  This is the framework for the HyperBus which can be used by
>> +	  the HyperBus Controller driver to communicate with
>> +	  HyperFlash. See Cypress HyperBus specification for more
>> +	  details
>> diff --git a/drivers/mtd/hyperbus/Makefile b/drivers/mtd/hyperbus/Makefile
>> new file mode 100644
>> index 000000000000..ca61dedd730d
>> --- /dev/null
>> +++ b/drivers/mtd/hyperbus/Makefile
>> @@ -0,0 +1,3 @@
>> +# SPDX-License-Identifier: GPL-2.0
>> +
>> +obj-$(CONFIG_MTD_HYPERBUS)	+= hyperbus-core.o
>> diff --git a/drivers/mtd/hyperbus/hyperbus-core.c b/drivers/mtd/hyperbus/hyperbus-core.c
>> new file mode 100644
>> index 000000000000..49aeb59742c6
>> --- /dev/null
>> +++ b/drivers/mtd/hyperbus/hyperbus-core.c
>> @@ -0,0 +1,192 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +//
>> +// Copyright (C) 2019 Texas Instruments Incorporated - http://www.ti.com/
>> +// Author: Vignesh Raghavendra <vigneshr@ti.com>
> [...]
>> +/* Default calibration routine for use by HyperBus controller.
>> + * Controller is calibrated by repeatedly reading known pattern ("QRY"
>> + * string from CFI space)
>> + * Lets ensure "QRY" string is read correctly at least 5 times to ensure
>> + * stability of the DLL lock.
>> + */
>> +int hyperbus_calibrate(struct hyperbus_device *hbdev)
>> +{
>> +	struct map_info *map = &hbdev->map;
>> +	struct cfi_private cfi;
>> +	int count = HYPERBUS_CALIB_COUNT;
>> +	int pass_count = 0;
>> +	int ret;
>> +
>> +	cfi.interleave = 1;
>> +	cfi.device_type = CFI_DEVICETYPE_X16;
>> +	cfi_send_gen_cmd(0xF0, 0, 0, map, &cfi, cfi.device_type, NULL);
>> +	cfi_send_gen_cmd(0x98, 0x55, 0, map, &cfi, cfi.device_type, NULL);
>> +
>> +	while (count--) {
>> +		cfi_qry_present(map, 0, &cfi);
>> +		ret = cfi_qry_present(map, 0, &cfi);
> 
>    Why call it twice in a row?
> 

Oops, will fix in v2

>> +		if (ret)
>> +			pass_count++;
>> +		else
>> +			pass_count = 0;
>> +		if (pass_count == 5)
>> +			break;
>> +	}
>> +
>> +	cfi_qry_mode_off(0, map, &cfi);
>> +
>> +	return ret;
>> +}
>> +EXPORT_SYMBOL_GPL(hyperbus_calibrate);
> [...]
>> diff --git a/include/linux/mtd/hyperbus.h b/include/linux/mtd/hyperbus.h
>> new file mode 100644
>> index 000000000000..19340cc56aa4
>> --- /dev/null
>> +++ b/include/linux/mtd/hyperbus.h
>> @@ -0,0 +1,91 @@
> [...]
>> +/**
>> + * hb_unregister_device - deregister HyperBus slave memory device
> 
>    You forgot to update the function name in the kernel-doc. :-)
> 

Indeed, thanks for catching this!

>> + * @hbdev: hyperbus_device to be unregistered
>> + *
>> + * Return: 0 for success, others for failure.
>> + */
>> +int hyperbus_unregister_device(struct hyperbus_device *hbdev);
>> +
>> +#endif /* __LINUX_MTD_HYPERBUS_H__ */
> 
> MBR, Sergei
> 

-- 
Regards
Vignesh

Re: [PATCH v3 0/5] MTD: Add Initial Hyperbus support

[Vignesh Raghavendra]

Hi Sergei,

On 12/04/19 2:59 PM, Vignesh Raghavendra wrote:
> Vignesh Raghavendra (5):
>    mtd: cfi_cmdset_0002: Add support for polling status register
>    dt-bindings: mtd: Add binding documentation for HyperFlash
>    mtd: Add support for HyperBus memory devices
>    dt-bindings: mtd: Add bindings for TI's AM654 HyperBus memory
>      controller
>    mtd: hyperbus: Add driver for TI's HyperBus memory controller
> 

Thanks for all the reviews!
Were you able to test this series with your hardware? Would like to get 
this into v5.2-rc1 if possible

Regards
Vignesh

Re: [PATCH v3 0/5] MTD: Add Initial Hyperbus support

[Sergei Shtylyov]

Hello!

On 04/17/2019 08:24 PM, Vignesh Raghavendra wrote:

>> Vignesh Raghavendra (5):
>>    mtd: cfi_cmdset_0002: Add support for polling status register
>>    dt-bindings: mtd: Add binding documentation for HyperFlash
>>    mtd: Add support for HyperBus memory devices
>>    dt-bindings: mtd: Add bindings for TI's AM654 HyperBus memory
>>      controller
>>    mtd: hyperbus: Add driver for TI's HyperBus memory controller
>>
> 
> Thanks for all the reviews!
> Were you able to test this series with your hardware? Would like to get this into v5.2-rc1 if possible

   Not yet, and I still haven't ported my driver to use your HyperBus code.

> Regards
> Vignesh

MBR, Sergei

[PATCH v3 4/5] dt-bindings: mtd: Add bindings for TI's AM654 HyperBus memory controller

[Vignesh Raghavendra]

Add binding documentation for TI's HyperBus memory controller present on
AM654 SoC.

Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
---
 .../devicetree/bindings/mtd/ti,am654-hbmc.txt | 31 +++++++++++++++++++
 MAINTAINERS                                   |  1 +
 2 files changed, 32 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mtd/ti,am654-hbmc.txt

diff --git a/Documentation/devicetree/bindings/mtd/ti,am654-hbmc.txt b/Documentation/devicetree/bindings/mtd/ti,am654-hbmc.txt
new file mode 100644
index 000000000000..00888482df25
--- /dev/null
+++ b/Documentation/devicetree/bindings/mtd/ti,am654-hbmc.txt
@@ -0,0 +1,31 @@
+Bindings for HyperBus Memory Controller (HBMC) on TI's K3 family of SoCs
+
+Required properties:
+- compatible : "ti,am654-hbmc" for AM654 SoC
+- reg : Two entries:
+	First entry pointed to the register space of HBMC controller
+	Second entry pointing to the memory map region dedicated for
+	MMIO access to attached flash devices
+- ranges : Address range allocated for each chipselect in the MMIO space
+
+Optional properties:
+- mux-controls: phandle to the multiplexer that controls selection of
+		HBMC vs OSPI. Mux state of 1 indicates HBMC is selected.
+
+Example:
+	hbmc: hbmc@47034000 {
+		compatible = "ti,am654-hbmc";
+		reg = <0x0 0x47034000 0x0 0x100>,
+			<0x5 0x00000000 0x1 0x0000000>;
+		power-domains = <&k3_pds 55>;
+		#address-cells = <1>;
+		#size-cells = <1>;
+		ranges = <0x0 0x5 0x00000000 0x4000000>, /* CS0 - 64MB */
+			 <0x1 0x5 0x04000000 0x4000000>; /* CS1 - 64MB
+
+		/* Slave flash node */
+		flash@0{
+			compatible = "cypress,hyperflash";
+			reg = <0x0 0x4000000>;
+		};
+	};
diff --git a/MAINTAINERS b/MAINTAINERS
index 7aa1b3454a89..07455035fca9 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -7249,6 +7249,7 @@ S:	Supported
 F:	drivers/mtd/hyperbus/
 F:	include/linux/mtd/hyperbus.h
 F:	Documentation/devicetree/bindings/mtd/cypress,hyperbus.txt
+F:	Documentation/devicetree/bindings/mtd/ti,am654-hbmc.txt
 
 HYPERVISOR VIRTUAL CONSOLE DRIVER
 L:	linuxppc-dev@lists.ozlabs.org
-- 
2.21.0