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* [PATCH v3 0/2] ZII RAVE platform driver
@ 2017-07-24 15:09 Andrey Smirnov
  2017-07-24 15:09 ` [PATCH v3 1/2] platform: Add driver for RAVE Supervisory Processor Andrey Smirnov
  2017-07-24 15:09 ` [PATCH v3 2/2] dt-bindings: mfd: Add bindings for ZII RAVE devices Andrey Smirnov
  0 siblings, 2 replies; 9+ messages in thread
From: Andrey Smirnov @ 2017-07-24 15:09 UTC (permalink / raw)
  To: linux-kernel
  Cc: Andrey Smirnov, cphealy, Lucas Stach, Nikita Yushchenko,
	Rob Herring, Mark Rutland, devicetree, Andy Shevchenko

Hi everyone,

This patch series is v3 of the driver for supervisory processor found
on RAVE series of devices from ZII. Supervisory processor is a PIC
microcontroller connected to various electrical subsystems on RAVE
devices whose firmware implements protocol to command/qery them.

Changes since [v2]:

    - Fixed swapped command codes in rave_sp_common_get_boot_source()
      and rave_sp_common_set_boot_source() revealed by further testing
      of the code

    - Incorporated feedback from Andy Shevchenko

Changes since [v1]:

    - Updated wording in DT-bindings as per Rob's request.

    - Collected Rob's Acked-by for patch 2/2

NOTE:

 * The driver for "zii,rave-sp-watchdog" exists, but I haven't
   submitted it yet, becuase I wanted to make sure that API exposed by
   this MFD is acceptable and doesn't need drastic changes.

 * This driver is dependent on crc_ccitt_false() introduced in
   2da9378d531f8cc6670c7497f20d936b706ab80b in 'linux-next'

Feedback is greatly appreciated!

Thanks,
Andrey Smirnov

[v2] lkml.kernel.org/r/20170718175604.11735-1-andrew.smirnov@gmail.com
[v1] lkml.kernel.org/r/20170710170449.4544-1-andrew.smirnov@gmail.com


Andrey Smirnov (2):
  platform: Add driver for RAVE Supervisory Processor
  dt-bindings: mfd: Add bindings for ZII RAVE devices

 .../devicetree/bindings/mfd/zii,rave-sp.txt        |   39 +
 drivers/mfd/Makefile                               |    1 +
 drivers/platform/Kconfig                           |    2 +
 drivers/platform/Makefile                          |    1 +
 drivers/platform/rave/Kconfig                      |   26 +
 drivers/platform/rave/Makefile                     |    1 +
 drivers/platform/rave/rave-sp.c                    | 1122 ++++++++++++++++++++
 include/linux/rave-sp.h                            |   54 +
 8 files changed, 1246 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mfd/zii,rave-sp.txt
 create mode 100644 drivers/platform/rave/Kconfig
 create mode 100644 drivers/platform/rave/Makefile
 create mode 100644 drivers/platform/rave/rave-sp.c
 create mode 100644 include/linux/rave-sp.h

-- 
2.13.3

^ permalink raw reply	[flat|nested] 9+ messages in thread

* [PATCH v3 1/2] platform: Add driver for RAVE Supervisory Processor
  2017-07-24 15:09 [PATCH v3 0/2] ZII RAVE platform driver Andrey Smirnov
@ 2017-07-24 15:09 ` Andrey Smirnov
  2017-07-24 17:25   ` Andy Shevchenko
  2017-07-24 15:09 ` [PATCH v3 2/2] dt-bindings: mfd: Add bindings for ZII RAVE devices Andrey Smirnov
  1 sibling, 1 reply; 9+ messages in thread
From: Andrey Smirnov @ 2017-07-24 15:09 UTC (permalink / raw)
  To: linux-kernel
  Cc: Andrey Smirnov, cphealy, Lucas Stach, Nikita Yushchenko, Andy Shevchenko

Add a driver for RAVE Supervisory Processor, an MCU implementing
varoius bits of housekeeping functionality (watchdoging, backlight
control, LED control, etc) on RAVE family of products by Zodiac
Inflight Innovations.

This driver implementes core MFD/serdev device as well as
communication subroutines necessary for commanding the device.

Cc: cphealy@gmail.com
Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: Nikita Yushchenko <nikita.yoush@cogentembedded.com>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
---
 drivers/mfd/Makefile            |    1 +
 drivers/platform/Kconfig        |    2 +
 drivers/platform/Makefile       |    1 +
 drivers/platform/rave/Kconfig   |   26 +
 drivers/platform/rave/Makefile  |    1 +
 drivers/platform/rave/rave-sp.c | 1122 +++++++++++++++++++++++++++++++++++++++
 include/linux/rave-sp.h         |   54 ++
 7 files changed, 1207 insertions(+)
 create mode 100644 drivers/platform/rave/Kconfig
 create mode 100644 drivers/platform/rave/Makefile
 create mode 100644 drivers/platform/rave/rave-sp.c
 create mode 100644 include/linux/rave-sp.h

diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index c16bf1ea0ea9..8796d65233ac 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -221,3 +221,4 @@ obj-$(CONFIG_MFD_SUN4I_GPADC)	+= sun4i-gpadc.o
 
 obj-$(CONFIG_MFD_STM32_TIMERS) 	+= stm32-timers.o
 obj-$(CONFIG_MFD_MXS_LRADC)     += mxs-lradc.o
+
diff --git a/drivers/platform/Kconfig b/drivers/platform/Kconfig
index c11db8bceea1..e6db685bb895 100644
--- a/drivers/platform/Kconfig
+++ b/drivers/platform/Kconfig
@@ -8,3 +8,5 @@ endif
 source "drivers/platform/goldfish/Kconfig"
 
 source "drivers/platform/chrome/Kconfig"
+
+source "drivers/platform/rave/Kconfig"
diff --git a/drivers/platform/Makefile b/drivers/platform/Makefile
index ca2692510733..17bdec5ece0c 100644
--- a/drivers/platform/Makefile
+++ b/drivers/platform/Makefile
@@ -7,3 +7,4 @@ obj-$(CONFIG_MIPS)		+= mips/
 obj-$(CONFIG_OLPC)		+= olpc/
 obj-$(CONFIG_GOLDFISH)		+= goldfish/
 obj-$(CONFIG_CHROME_PLATFORMS)	+= chrome/
+obj-y += rave/
diff --git a/drivers/platform/rave/Kconfig b/drivers/platform/rave/Kconfig
new file mode 100644
index 000000000000..6fc50ade3871
--- /dev/null
+++ b/drivers/platform/rave/Kconfig
@@ -0,0 +1,26 @@
+#
+# Platform support for Zodiac RAVE hardware
+#
+
+menuconfig RAVE_PLATFORMS
+	bool "Platform support for Zodiac RAVE hardware"
+	depends on SERIAL_DEV_BUS && SERIAL_DEV_CTRL_TTYPORT
+	help
+	  Say Y here to get to see options for platform support for
+	  various devices present in RAVE hardware. This option alone
+	  does not add any kernel code.
+
+	  If you say N, all options in this submenu will be skipped
+	  and disabled.
+
+if RAVE_PLATFORMS
+
+config RAVE_SP_CORE
+	tristate "RAVE SP MCU core driver"
+	select MFD_CORE
+	select CRC_CCITT
+	help
+	  Select this to get support for the Supervisory Processor
+	  device found on several devices in RAVE line of hardware.
+
+endif
diff --git a/drivers/platform/rave/Makefile b/drivers/platform/rave/Makefile
new file mode 100644
index 000000000000..e4c21ab2d2f5
--- /dev/null
+++ b/drivers/platform/rave/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_RAVE_SP_CORE) += rave-sp.o
diff --git a/drivers/platform/rave/rave-sp.c b/drivers/platform/rave/rave-sp.c
new file mode 100644
index 000000000000..6fc3b3d9f147
--- /dev/null
+++ b/drivers/platform/rave/rave-sp.c
@@ -0,0 +1,1122 @@
+/*
+ * Multifunction core driver for Zodiac Inflight Innovations
+ * SP MCU that is connected via dedicated UART port
+ *
+ * Copyright (C) 2017 Zodiac Inflight Innovations
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/atomic.h>
+#include <linux/crc-ccitt.h>
+#include <linux/delay.h>
+#include <linux/export.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/sched.h>
+#include <linux/serdev.h>
+#include <linux/rave-sp.h>
+
+/*
+ * UART protocol using following entities:
+ *  - message to MCU => ACK response
+ *  - event from MCU => event ACK
+ *
+ * Frame structure:
+ * <STX> <DATA> <CHECKSUM> <ETX>
+ * Where:
+ * - STX - is start of transmission character
+ * - ETX - end of transmission
+ * - DATA - payload
+ * - CHECKSUM - checksum calculated on <DATA>
+ *
+ * If <DATA> or <CHECKSUM> contain one of control characters, then it is
+ * escaped using <DLE> control code. Added <DLE> does not participate in
+ * checksum calculation.
+ */
+#define RAVE_SP_STX			0x02
+#define RAVE_SP_ETX			0x03
+#define RAVE_SP_DLE			0x10
+
+#define RAVE_SP_MAX_DATA_SIZE		64
+#define RAVE_SP_CHECKSUM_SIZE		2  /* Worst case scenario on RDU2 */
+/*
+ * We don't store STX, ETX and unescaped bytes, so Rx is only
+ * DATA + CSUM
+ */
+#define RAVE_SP_RX_BUFFER_SIZE		(RAVE_SP_MAX_DATA_SIZE + \
+					 RAVE_SP_CHECKSUM_SIZE)
+
+#define RAVE_SP_STX_ETX_SIZE		2
+/*
+ * For Tx we have to have space for everything, STX, EXT and
+ * potentially stuffed DATA + CSUM data + csum
+ */
+#define RAVE_SP_TX_BUFFER_SIZE		(RAVE_SP_STX_ETX_SIZE + \
+					 2 * RAVE_SP_RX_BUFFER_SIZE)
+
+#define RAVE_SP_BOOT_SOURCE_GET		0
+#define RAVE_SP_BOOT_SOURCE_SET		1
+
+#define RAVE_SP_RDU2_BOARD_TYPE_RMB	0
+#define RAVE_SP_RDU2_BOARD_TYPE_DEB	1
+
+#define RAVE_SP_BOOT_SOURCE_SD		0
+#define RAVE_SP_BOOT_SOURCE_EMMC	1
+#define RAVE_SP_BOOT_SOURCE_NOR		2
+
+/**
+ * enum rave_sp_deframer_state - Possible state for de-framer
+ *
+ * @RAVE_SP_EXPECT_SOF:	 scanning data stream for start of frame
+ *				 marker
+ * @RAVE_SP_EXPECT_DATA:	 start of frame marker detected, collecting
+ *				 frame
+ * @RAVE_SP_EXPECT_ESCAPED_DATA: escape character received, collecting
+ *				 escaped byte
+ */
+enum rave_sp_deframer_state {
+	RAVE_SP_EXPECT_SOF,
+	RAVE_SP_EXPECT_DATA,
+	RAVE_SP_EXPECT_ESCAPED_DATA,
+};
+
+/**
+ * struct rave_sp - Device protocol deframer
+ *
+ * @state:  Current state of the deframer
+ * @data:   Buffer used to collect deframed data
+ * @length: Number of bytes de-framed so far
+ */
+struct rave_sp_deframer {
+	enum rave_sp_deframer_state state;
+	unsigned char data[RAVE_SP_RX_BUFFER_SIZE];
+	size_t length;
+};
+
+/**
+ * struct rave_sp_reply - reply as per RAVE device protocol
+ *
+ * @length:	Expected reply length
+ * @data:	Buffer to store reply payload in
+ * @code:	Expected reply code
+ * @ackid:	Exptected reply ACK ID
+ * @completion: Successful reply reception completion
+ */
+struct rave_sp_reply {
+	size_t length;
+	void  *data;
+	u8     code;
+	u8     ackid;
+	struct completion received;
+};
+
+/**
+ * struct rave_sp_checksum - Variant specific checksum implementation details
+ *
+ * @length:	Caculated checksum length
+ * @subroutine: Utilized checksum algorithm implementation
+ */
+struct rave_sp_checksum {
+	size_t length;
+	void (*subroutine)(const u8 *, size_t, u8 *);
+};
+
+/**
+ * struct rave_sp_variant_cmds - Variant specific command vtable
+ *
+ * @translate: Subroutine to translate common command identifiers to
+ *	       device specific variants. Different generations of the
+ *	       ICD employed different numberical constants to
+ *	       represent same/similar commands and this function is
+ *	       there to address that.
+ *
+ * @get_boot_source: Variant dependent implementaion of "get boot
+ *		     source" operation
+ * @set_boot_source: Variant dependent implementaion of "set boot
+ *		     source" operation
+ */
+struct rave_sp_variant_cmds {
+	int (*translate)(enum rave_sp_command);
+	int (*get_boot_source)(struct rave_sp *);
+	int (*set_boot_source)(struct rave_sp *, u8);
+};
+
+/**
+ * struct rave_sp_variant - RAVE supervisory processor core variant
+ *
+ * @checksum:	Variant specific checksum implementation
+ * @cmd:	Variant specific command vtable
+ * @init:	Variant specific initialization sequence implementation
+ * @group:	Attrubute group for exposed sysfs entries
+ */
+struct rave_sp_variant {
+	const struct rave_sp_checksum *checksum;
+	struct rave_sp_variant_cmds cmd;
+	void (*init)(struct rave_sp *);
+	struct attribute_group group;
+};
+
+/**
+ * struct rave_sp - RAVE supervisory processor core
+ *
+ * @serdev:			Pointer to underlying serdev
+ * @deframer:			Stored state of the protocol deframer
+ * @ackid:			ACK ID used in last reply sent to the device
+ * @bus_lock:			Lock to serialize access to the device
+ * @reply_lock:			Lock protecting @reply
+ * @reply:			Pointer to memory to store reply payload
+ *
+ * @part_number_firmware:
+ * @part_number_bootloader:
+ * @reset_reason:
+ * @copper_rev_rmb:
+ * @copper_rev_deb:
+ * @silicon_devid:
+ * @silicon_devrev:
+ * @copper_mod_rmb:
+ * @copper_mod_deb:
+ *
+ * @variant:			Device variant specific parameters and
+ *				functions
+ * @event_notifier_list:	Input event notification chain (used with
+ *				corresponding input MFD cell driver)
+ * @group:			Attrubute group for exposed sysfs entries
+ *
+ *
+ * part_number_*, reset_reason, copper_*, and silicon_* fields are all
+ * strings retrived from the device during device probing and made
+ * availible for later userspace consumption via sysfs
+ *
+ */
+struct rave_sp {
+	struct serdev_device *serdev;
+
+	struct rave_sp_deframer deframer;
+	atomic_t ackid;
+
+	struct mutex bus_lock;
+	struct mutex reply_lock;
+	struct rave_sp_reply *reply;
+
+	const char *part_number_firmware;
+	const char *part_number_bootloader;
+
+	const char *reset_reason;
+	const char *copper_rev_rmb;
+	const char *copper_rev_deb;
+	const char *silicon_devid;
+	const char *silicon_devrev;
+
+	const char *copper_mod_rmb;
+	const char *copper_mod_deb;
+
+	const struct rave_sp_variant *variant;
+
+	struct blocking_notifier_head event_notifier_list;
+
+	struct attribute_group *group;
+};
+
+struct rave_sp_rsp_status {
+	u8 bl_bytes[6];
+	u8 fw_bytes[6];
+	u8 gs_format;
+} __packed;
+
+static bool rave_sp_id_is_event(u8 code)
+{
+	return (code & 0xF0) == RAVE_SP_EVNT_BASE;
+}
+
+static void rave_sp_unregister_event_notifier(struct device *dev, void *res)
+{
+	struct rave_sp *sp = dev_get_drvdata(dev->parent);
+	struct notifier_block *nb = *(struct notifier_block **)res;
+	struct blocking_notifier_head *bnh = &sp->event_notifier_list;
+
+	WARN_ON(blocking_notifier_chain_unregister(bnh, nb));
+}
+
+int devm_rave_sp_register_event_notifier(struct device *dev,
+					 struct notifier_block *nb)
+{
+	struct rave_sp *sp = dev_get_drvdata(dev->parent);
+	struct notifier_block **rcnb;
+	int ret;
+
+	rcnb = devres_alloc(rave_sp_unregister_event_notifier,
+			    sizeof(*rcnb), GFP_KERNEL);
+	if (!rcnb)
+		return -ENOMEM;
+
+	ret = blocking_notifier_chain_register(&sp->event_notifier_list, nb);
+	if (!ret) {
+		*rcnb = nb;
+		devres_add(dev, rcnb);
+	} else {
+		devres_free(rcnb);
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(devm_rave_sp_register_event_notifier);
+
+static const char *devm_rave_sp_version(struct device *dev, const char *buf)
+{
+	/*
+	 * NOTE: Ther format string below uses %02d to display u16
+	 * intentionally for the sake of backwards compatibility with
+	 * legacy software.
+	 */
+	return devm_kasprintf(dev, GFP_KERNEL, "%02d%02d%02d.%c%c\n",
+			      buf[0], le16_to_cpup((const __le16 *)&buf[1]),
+			      buf[3], buf[4], buf[5]);
+}
+
+static int rave_sp_get_status(struct rave_sp *sp,
+			      struct rave_sp_rsp_status *status)
+{
+	u8 cmd[] = {
+		[0] = RAVE_SP_CMD_STATUS,
+		[1] = 0
+	};
+	return rave_sp_exec(sp, cmd, sizeof(cmd), status, sizeof(*status));
+}
+
+#define RAVE_SP_ATTR_RO_STRING(name)					\
+	static ssize_t							\
+	name##_show(struct device *dev,					\
+		    struct device_attribute *attr,			\
+		    char *buf)						\
+	{								\
+		struct rave_sp *sp = dev_get_drvdata(dev);		\
+		return sprintf(buf, "%s", sp->name);			\
+	}								\
+	static DEVICE_ATTR_RO(name)
+
+RAVE_SP_ATTR_RO_STRING(part_number_firmware);
+RAVE_SP_ATTR_RO_STRING(part_number_bootloader);
+RAVE_SP_ATTR_RO_STRING(copper_rev_rmb);
+RAVE_SP_ATTR_RO_STRING(copper_rev_deb);
+RAVE_SP_ATTR_RO_STRING(reset_reason);
+RAVE_SP_ATTR_RO_STRING(silicon_devrev);
+RAVE_SP_ATTR_RO_STRING(silicon_devid);
+
+RAVE_SP_ATTR_RO_STRING(copper_mod_rmb);
+RAVE_SP_ATTR_RO_STRING(copper_mod_deb);
+
+static ssize_t
+i2c_device_status_show(struct device *dev,
+		    struct device_attribute *attr,
+		    char *buf)
+{
+	ssize_t ret;
+	struct rave_sp *sp = dev_get_drvdata(dev);
+	u8 status[2];
+	u8 cmd[] = {
+		[0] = RAVE_SP_CMD_GET_I2C_DEVICE_STATUS,
+		[1] = 0
+	};
+
+	ret = rave_sp_exec(sp, cmd, sizeof(cmd), &status, sizeof(status));
+	if (ret < 0)
+		return ret;
+
+	return sprintf(buf, "%04x\n", le16_to_cpup((__le16 *)status));
+}
+static DEVICE_ATTR_RO(i2c_device_status);
+
+static int rave_sp_rdu1_get_boot_source(struct rave_sp *sp)
+{
+	struct rave_sp_rsp_status status;
+	int ret;
+
+	ret = rave_sp_get_status(sp, &status);
+
+	return (ret < 0) ? ret : (status.gs_format >> 2) & 0x03;
+}
+
+static int rave_sp_rdu1_set_boot_source(struct rave_sp *sp, u8 boot_source)
+{
+	return -ENOTSUPP;
+}
+
+static int rave_sp_common_set_boot_source(struct rave_sp *sp, u8 boot_source)
+{
+	u8 cmd[] = {
+		[0] = RAVE_SP_CMD_BOOT_SOURCE,
+		[1] = 0,
+		[2] = RAVE_SP_BOOT_SOURCE_SET,
+		[3] = boot_source,
+	};
+
+	return rave_sp_exec(sp, cmd, sizeof(cmd), NULL, 0);
+}
+
+static int rave_sp_common_get_boot_source(struct rave_sp *sp)
+{
+	u8 cmd[] = {
+		[0] = RAVE_SP_CMD_BOOT_SOURCE,
+		[1] = 0,
+		[2] = RAVE_SP_BOOT_SOURCE_GET,
+		[3] = 0,
+	};
+	u8 boot_source;
+	int ret;
+
+	ret = rave_sp_exec(sp, cmd, sizeof(cmd),
+			   &boot_source, sizeof(boot_source));
+
+	return (ret < 0) ? ret : boot_source;
+}
+
+static ssize_t rave_sp_show_boot_source(struct device *dev,
+					struct device_attribute *attr,
+					char *buf)
+{
+	struct rave_sp *sp = dev_get_drvdata(dev);
+	int ret;
+
+	ret = sp->variant->cmd.get_boot_source(sp);
+
+	return (ret < 0) ? ret : sprintf(buf, "%d\n", ret);
+}
+
+static ssize_t rave_sp_store_boot_source(struct device *dev,
+					 struct device_attribute *attr,
+					 const char *buf, size_t count)
+{
+	struct rave_sp *sp = dev_get_drvdata(dev);
+	u8 boot_source;
+	int ret;
+
+	ret = kstrtou8(buf, 0, &boot_source);
+	if (ret)
+		return ret;
+
+	if (boot_source != RAVE_SP_BOOT_SOURCE_SD &&
+	    boot_source != RAVE_SP_BOOT_SOURCE_EMMC &&
+	    boot_source != RAVE_SP_BOOT_SOURCE_NOR)
+		return -EINVAL;
+
+	ret = sp->variant->cmd.set_boot_source(sp, boot_source);
+
+	return (ret < 0) ? ret : count;
+}
+
+static DEVICE_ATTR(boot_source, 0640,
+		   rave_sp_show_boot_source, rave_sp_store_boot_source);
+
+static void devm_rave_sp_sysfs_group_release(struct device *dev, void *res)
+{
+	struct rave_sp *sp = *(struct rave_sp **)res;
+	const struct attribute_group *group = &sp->variant->group;
+	struct kobject *root = &sp->serdev->dev.kobj;
+
+	sysfs_remove_group(root, group);
+}
+
+static int devm_rave_sysfs_create_group(struct rave_sp *sp)
+{
+	struct rave_sp **rcsp;
+	struct device *dev = &sp->serdev->dev;
+	const struct attribute_group *group = &sp->variant->group;
+	struct kobject *root = &dev->kobj;
+	int ret;
+
+	rcsp = devres_alloc(devm_rave_sp_sysfs_group_release,
+			     sizeof(*rcsp), GFP_KERNEL);
+	if (!rcsp)
+		return -ENOMEM;
+
+	ret = sysfs_create_group(root, group);
+	if (!ret) {
+		*rcsp = sp;
+		devres_add(dev, rcsp);
+	} else {
+		devres_free(rcsp);
+	}
+
+	return ret;
+}
+
+static void csum_8b2c(const u8 *buf, size_t size, u8 *crc)
+{
+	*crc = *buf++;
+	size--;
+
+	while (size--)
+		*crc += *buf++;
+
+	*crc = 1 + ~(*crc);
+}
+
+static void csum_ccitt(const u8 *buf, size_t size, u8 *crc)
+{
+
+	const u16 calculated = crc_ccitt_false(0xffff, buf, size);
+
+	/*
+	 * While the rest of the wire protocol is little-endian,
+	 * CCITT-16 CRC in RDU2 device is sent out in big-endian order.
+	 */
+	*(__be16 *)crc = cpu_to_be16(calculated);
+}
+
+static void *stuff(unsigned char *dest, const unsigned char *src, size_t n)
+{
+	while (n--) {
+		const unsigned char byte = *src++;
+
+		switch (byte) {
+		case RAVE_SP_STX:
+		case RAVE_SP_ETX:
+		case RAVE_SP_DLE:
+			*dest++ = RAVE_SP_DLE;
+		default:
+			*dest++ = byte;
+		}
+	}
+
+	return dest;
+}
+
+static int rave_sp_write(struct rave_sp *sp, const u8 *data, u8 data_size)
+{
+	size_t length;
+	const size_t checksum_length = sp->variant->checksum->length;
+	unsigned char crc[checksum_length];
+	unsigned char frame[RAVE_SP_TX_BUFFER_SIZE];
+	unsigned char *dest = frame;
+
+	if (WARN_ON(data_size > sizeof(frame)))
+		return -ENOMEM;
+
+	sp->variant->checksum->subroutine(data, data_size, crc);
+
+	*dest++ = RAVE_SP_STX;
+	dest = stuff(dest, data, data_size);
+	dest = stuff(dest, crc, checksum_length);
+	*dest++ = RAVE_SP_ETX;
+
+	length = dest - frame;
+
+	print_hex_dump(KERN_DEBUG, "rave-sp tx: ", DUMP_PREFIX_NONE,
+		       16, 1, frame, length, false);
+
+	return serdev_device_write(sp->serdev, frame, length, HZ);
+}
+
+static u8 rave_sp_reply_code(u8 command)
+{
+	/*
+	 * There isn't a signle rule that describes command code ->
+	 * ACK code transformation, but, going through various
+	 * versions of ICDs, there appear to be three distinct groups
+	 * that can be described by simple transformation.
+	 */
+	switch (command) {
+	case 0xA0 ... 0xBE:
+		/*
+		 * Commands implemented by firmware found in RDU1 and
+		 * older devices all seem to obey the following rule
+		 */
+		return command + 0x20;
+	case 0xE0 ... 0xEF:
+		/*
+		 * Events emitted by all version of the firmare use
+		 * least signifiact bit to get an ACK code
+		 */
+		return command | 0x01;
+	default:
+		/*
+		 * Commands implemented by firmware found in RDU2 are
+		 * similar to "old" commands, but they use slightly
+		 * different offset
+		 */
+		return command + 0x40;
+	}
+}
+
+int rave_sp_exec(struct rave_sp *sp,
+		 void *__data,  size_t data_size,
+		 void *reply_data, size_t reply_data_size)
+{
+	int ret = 0;
+	unsigned char *data = __data;
+	const u8 ackid = (u8)atomic_inc_return(&sp->ackid);
+	const int command = sp->variant->cmd.translate(data[0]);
+	struct rave_sp_reply reply = {
+		.code     = rave_sp_reply_code((u8)command),
+		.ackid    = ackid,
+		.data     = reply_data,
+		.length   = reply_data_size,
+		.received = COMPLETION_INITIALIZER_ONSTACK(reply.received),
+	};
+
+	if (command < 0)
+		return command;
+
+	mutex_lock(&sp->bus_lock);
+
+	mutex_lock(&sp->reply_lock);
+	sp->reply = &reply;
+	mutex_unlock(&sp->reply_lock);
+
+	data[0] = (u8)command;
+	data[1] = ackid;
+
+	rave_sp_write(sp, data, data_size);
+
+	if (!wait_for_completion_timeout(&reply.received, HZ)) {
+		dev_err(&sp->serdev->dev, "Command timeout\n");
+		ret = -ETIMEDOUT;
+
+		mutex_lock(&sp->reply_lock);
+		sp->reply = NULL;
+		mutex_unlock(&sp->reply_lock);
+	}
+
+	mutex_unlock(&sp->bus_lock);
+	return ret;
+}
+EXPORT_SYMBOL(rave_sp_exec);
+
+static void rave_sp_receive_event(struct rave_sp *sp,
+				  const unsigned char *data, size_t length)
+{
+	u8 cmd[] = {
+		[0] = rave_sp_reply_code(data[0]),
+		[1] = data[1],
+	};
+
+	rave_sp_write(sp, cmd, sizeof(cmd));
+
+	blocking_notifier_call_chain(&sp->event_notifier_list,
+				     rave_sp_action_pack(data[0], data[2]),
+				     NULL);
+}
+
+static void rave_sp_receive_reply(struct rave_sp *sp,
+				  const unsigned char *data, size_t length)
+{
+	struct device *dev = &sp->serdev->dev;
+	struct rave_sp_reply *reply;
+	const  size_t payload_length = length - 2;
+
+	mutex_lock(&sp->reply_lock);
+	reply = sp->reply;
+
+	if (reply) {
+		if (reply->code == data[0] && reply->ackid == data[1] &&
+		    payload_length >= reply->length) {
+			/*
+			 * We are relying on memcpy(dst, src, 0) to be a no-op
+			 * when handling commands that have a no-payload reply
+			 */
+			memcpy(reply->data, &data[2], reply->length);
+			complete(&reply->received);
+			sp->reply = NULL;
+		} else {
+			dev_err(dev, "Ignoring incorrect reply\n");
+			dev_dbg(dev, "Code:   expected = 0x%08x received = 0x%08x\n",
+				reply->code, data[0]);
+			dev_dbg(dev, "ACK ID: expected = 0x%08x received = 0x%08x\n",
+				reply->ackid, data[1]);
+			dev_dbg(dev, "Length: expected = %zu received = %zu\n",
+				reply->length, payload_length);
+		}
+	}
+
+	mutex_unlock(&sp->reply_lock);
+}
+
+static void rave_sp_receive_frame(struct rave_sp *sp,
+				  const unsigned char *data,
+				  size_t length)
+{
+	const size_t checksum_length = sp->variant->checksum->length;
+	const size_t payload_length  = length - checksum_length;
+	const u8 *crc_reported       = &data[payload_length];
+	struct device *dev           = &sp->serdev->dev;
+	u8 crc_calculated[checksum_length];
+
+	print_hex_dump(KERN_DEBUG, "rave-sp rx: ", DUMP_PREFIX_NONE,
+		       16, 1, data, length, false);
+
+	if (unlikely(length <= checksum_length)) {
+		dev_warn(dev, "Dropping short frame\n");
+		return;
+	}
+
+	sp->variant->checksum->subroutine(data, payload_length,
+					  crc_calculated);
+
+	if (memcmp(crc_calculated, crc_reported, checksum_length)) {
+		dev_warn(dev, "Dropping bad frame\n");
+		return;
+	}
+
+	if (rave_sp_id_is_event(data[0]))
+		rave_sp_receive_event(sp, data, length);
+	else
+		rave_sp_receive_reply(sp, data, length);
+}
+
+static int rave_sp_receive_buf(struct serdev_device *serdev,
+			       const unsigned char *buf, size_t size)
+{
+	struct device *dev  = &serdev->dev;
+	struct rave_sp *sp = dev_get_drvdata(dev);
+	struct rave_sp_deframer *deframer = &sp->deframer;
+	const unsigned char *src = buf;
+	const unsigned char *end = buf + size;
+	bool reset_framer = false;
+
+	while (src < end) {
+		const unsigned char byte = *src++;
+
+		switch (deframer->state) {
+
+		case RAVE_SP_EXPECT_SOF:
+			if (byte == RAVE_SP_STX)
+				deframer->state = RAVE_SP_EXPECT_DATA;
+			continue;
+
+		case RAVE_SP_EXPECT_DATA:
+			switch (byte) {
+			case RAVE_SP_ETX:
+				rave_sp_receive_frame(sp,
+						      deframer->data,
+						      deframer->length);
+				reset_framer = true;
+				break;
+			case RAVE_SP_STX:
+				dev_warn(dev, "Bad frame: STX before ETX\n");
+				reset_framer = true;
+				break;
+			case RAVE_SP_DLE:
+				deframer->state = RAVE_SP_EXPECT_ESCAPED_DATA;
+				continue;
+			}
+
+		case RAVE_SP_EXPECT_ESCAPED_DATA: /* FALLTHROUGH */
+			deframer->data[deframer->length++] = byte;
+
+			if (deframer->length == sizeof(deframer->data)) {
+				dev_warn(dev, "Bad frame: Too long\n");
+				reset_framer = true;
+				break;
+			}
+
+			deframer->state = RAVE_SP_EXPECT_DATA;
+			break;
+		}
+	}
+
+	if (reset_framer) {
+		deframer->state  = RAVE_SP_EXPECT_SOF;
+		deframer->length = 0;
+	}
+
+	return src - buf;
+}
+
+static int rave_sp_rdu1_cmd_translate(enum rave_sp_command command)
+{
+	if (command >= RAVE_SP_CMD_STATUS &&
+	    command <= RAVE_SP_CMD_CONTROL_EVENTS)
+		return command;
+
+	return -EINVAL;
+}
+
+static int rave_sp_rdu2_cmd_translate(enum rave_sp_command command)
+{
+	if (command >= RAVE_SP_CMD_GET_FIRMWARE_VERSION &&
+	    command <= RAVE_SP_CMD_GET_GPIO_STATE)
+		return command;
+
+	if (command == RAVE_SP_CMD_REQ_COPPER_REV)
+		return 0x28;
+
+	return rave_sp_rdu1_cmd_translate(command);
+}
+
+static int rave_sp_default_cmd_translate(enum rave_sp_command command)
+{
+	switch (command) {
+	case RAVE_SP_CMD_GET_FIRMWARE_VERSION:
+		return 0x11;
+	case RAVE_SP_CMD_GET_BOOTLOADER_VERSION:
+		return 0x12;
+	case RAVE_SP_CMD_BOOT_SOURCE:
+		return 0x14;
+	case RAVE_SP_CMD_SW_WDT:
+		return 0x1C;
+	case RAVE_SP_CMD_RESET:
+		return 0x1E;
+	case RAVE_SP_CMD_RESET_REASON:
+		return 0x1F;
+	default:
+		return -EINVAL;
+	}
+}
+
+static void rave_sp_load_reset_reason(struct rave_sp *sp)
+{
+	struct device *dev = &sp->serdev->dev;
+	u8 cmd[] = {
+		[0] = RAVE_SP_CMD_RESET_REASON,
+		[1] = 0,
+	};
+	u8 reason;
+	int ret;
+
+	ret = rave_sp_exec(sp, cmd, sizeof(cmd), &reason, sizeof(reason));
+	if (ret) {
+		dev_err(dev, "CMD_RESET_REASON failed %d\n", ret);
+		return;
+	}
+
+	sp->reset_reason = devm_kasprintf(dev, GFP_KERNEL, "%02x\n", reason);
+}
+
+static const char *rave_sp_silicon_to_string(struct device *dev,
+					     const __le32 *version)
+{
+	return devm_kasprintf(dev, GFP_KERNEL, "%08x\n", le32_to_cpup(version));
+}
+
+static const char *rave_sp_copper_to_string(struct device *dev, uint8_t version)
+{
+	return devm_kasprintf(dev, GFP_KERNEL, "%02x\n", version);
+}
+
+
+static void rave_sp_load_silicon_rev(struct rave_sp *sp)
+{
+	struct device *dev = &sp->serdev->dev;
+	u8 cmd[] = {
+		[0] = RAVE_SP_CMD_GET_SP_SILICON_REV,
+		[1] = 0
+	};
+	struct {
+		__le32 devid;
+		__le32 devrev;
+	} __packed reply;
+	int ret;
+
+	ret = rave_sp_exec(sp, cmd, sizeof(cmd), &reply, sizeof(reply));
+	if (ret) {
+		dev_err(dev, "CMD_GET_SP_SILICON_REV failed %d\n", ret);
+		return;
+	}
+
+	sp->silicon_devid  = rave_sp_silicon_to_string(dev, &reply.devid);
+	sp->silicon_devrev = rave_sp_silicon_to_string(dev, &reply.devrev);
+}
+
+static void rave_sp_rdu1_init(struct rave_sp *sp)
+{
+	struct device *dev = &sp->serdev->dev;
+	u8 cmd[] = {
+		[0] = RAVE_SP_CMD_REQ_COPPER_REV,
+		[1] = 0
+	};
+	struct rave_sp_rsp_status status;
+	u8 revision[2];
+	int ret;
+
+	ret = rave_sp_get_status(sp, &status);
+	if (ret) {
+		dev_err(dev, "CMD_STATUS failed %d\n", ret);
+	} else {
+		sp->part_number_firmware =
+			devm_rave_sp_version(dev, status.fw_bytes);
+		sp->part_number_bootloader =
+			devm_rave_sp_version(dev, status.bl_bytes);
+	}
+
+	ret = rave_sp_exec(sp, cmd, sizeof(cmd), &revision, sizeof(revision));
+	if (ret) {
+		dev_err(dev, "CMD_REQ_COPPER_REV failed %d\n", ret);
+		return;
+	}
+
+	sp->copper_rev_rmb = rave_sp_copper_to_string(dev, revision[0]);
+	sp->copper_rev_deb = rave_sp_copper_to_string(dev, revision[1]);
+}
+
+static void rave_sp_common_init(struct rave_sp *sp)
+{
+	struct device *dev = &sp->serdev->dev;
+	u8 version[6];
+	u8 cmd[2];
+	int ret;
+
+	cmd[0] = RAVE_SP_CMD_GET_FIRMWARE_VERSION;
+	ret = rave_sp_exec(sp, cmd, sizeof(cmd), version, sizeof(version));
+	if (ret)
+		dev_warn(dev, "CMD_GET_FIRMWARE_VERSION failed %d\n", ret);
+	else
+		sp->part_number_firmware = devm_rave_sp_version(dev, version);
+
+	cmd[0] = RAVE_SP_CMD_GET_BOOTLOADER_VERSION;
+	ret = rave_sp_exec(sp, cmd, sizeof(cmd), version, sizeof(version));
+	if (ret) {
+		dev_warn(dev, "CMD_GET_BOOTLOADER_VERSION failed %d\n", ret);
+		return;
+	}
+
+	sp->part_number_bootloader = devm_rave_sp_version(dev, version);
+}
+
+static void rave_sp_rdu2_init(struct rave_sp *sp)
+{
+	struct device *dev = &sp->serdev->dev;
+	u8 cmd[] = {
+		[0] = RAVE_SP_CMD_REQ_COPPER_REV,
+		[1] = 0,
+		[2] = RAVE_SP_RDU2_BOARD_TYPE_RMB,
+	};
+	u8 copper_rev;
+	int ret;
+
+	rave_sp_common_init(sp);
+
+	ret = rave_sp_exec(sp, cmd, sizeof(cmd),
+			   &copper_rev, sizeof(copper_rev));
+	if (ret) {
+		dev_warn(dev,
+			 "RAVE_SP_CMD_REQ_COPPER_REV(RMB) failed %d\n", ret);
+	} else {
+		sp->copper_rev_rmb =
+			rave_sp_copper_to_string(dev, copper_rev & 0x1F);
+		sp->copper_mod_rmb =
+			rave_sp_copper_to_string(dev, copper_rev >> 5);
+	}
+
+	cmd[2] = RAVE_SP_RDU2_BOARD_TYPE_DEB;
+
+	ret = rave_sp_exec(sp, cmd, sizeof(cmd),
+			   &copper_rev, sizeof(copper_rev));
+	if (ret) {
+		dev_warn(dev,
+			 "RAVE_SP_CMD_REQ_COPPER_REV(DEB) failed %d\n", ret);
+		return;
+	}
+
+	sp->copper_rev_deb = rave_sp_copper_to_string(dev,
+						      copper_rev & 0x1F);
+	sp->copper_mod_deb = rave_sp_copper_to_string(dev,
+						      copper_rev >> 5);
+}
+
+static const struct rave_sp_checksum rave_sp_checksum_8b2c = {
+	.length     = 1,
+	.subroutine = csum_8b2c,
+};
+
+static const struct rave_sp_checksum rave_sp_checksum_ccitt = {
+	.length     = 2,
+	.subroutine = csum_ccitt,
+};
+
+static struct attribute *rave_sp_common_attrs[] = {
+	&dev_attr_part_number_firmware.attr,
+	&dev_attr_part_number_bootloader.attr,
+	&dev_attr_boot_source.attr,
+	&dev_attr_reset_reason.attr,
+	NULL
+};
+
+static struct attribute *rave_sp_rdu1_attrs[] = {
+	&dev_attr_part_number_firmware.attr,
+	&dev_attr_part_number_bootloader.attr,
+	&dev_attr_boot_source.attr,
+	&dev_attr_reset_reason.attr,
+	&dev_attr_copper_rev_deb.attr,
+	&dev_attr_copper_rev_rmb.attr,
+	&dev_attr_i2c_device_status.attr,
+	&dev_attr_silicon_devid.attr,
+	&dev_attr_silicon_devrev.attr,
+
+	NULL
+};
+
+static struct attribute *rave_sp_rdu2_attrs[] = {
+	&dev_attr_part_number_firmware.attr,
+	&dev_attr_part_number_bootloader.attr,
+	&dev_attr_boot_source.attr,
+	&dev_attr_reset_reason.attr,
+	&dev_attr_copper_rev_deb.attr,
+	&dev_attr_copper_rev_rmb.attr,
+	&dev_attr_i2c_device_status.attr,
+	&dev_attr_silicon_devid.attr,
+	&dev_attr_silicon_devrev.attr,
+
+	&dev_attr_copper_mod_rmb.attr,
+	&dev_attr_copper_mod_deb.attr,
+
+	NULL
+};
+
+static const struct rave_sp_variant rave_sp_legacy = {
+	.checksum = &rave_sp_checksum_8b2c,
+	.cmd = {
+		.translate = rave_sp_default_cmd_translate,
+		.get_boot_source = rave_sp_common_get_boot_source,
+		.set_boot_source = rave_sp_common_set_boot_source,
+	},
+	.group = {
+		.attrs = rave_sp_common_attrs,
+	},
+	.init = rave_sp_common_init,
+};
+
+static const struct rave_sp_variant rave_sp_rdu1 = {
+	.checksum = &rave_sp_checksum_8b2c,
+	.cmd = {
+		.translate = rave_sp_rdu1_cmd_translate,
+		.get_boot_source = rave_sp_rdu1_get_boot_source,
+		.set_boot_source = rave_sp_rdu1_set_boot_source,
+	},
+	.group = {
+		.attrs = rave_sp_rdu1_attrs,
+	},
+	.init = rave_sp_rdu1_init,
+};
+
+static const struct rave_sp_variant rave_sp_rdu2 = {
+	.checksum = &rave_sp_checksum_ccitt,
+	.cmd = {
+		.translate = rave_sp_rdu2_cmd_translate,
+		.get_boot_source = rave_sp_common_get_boot_source,
+		.set_boot_source = rave_sp_common_set_boot_source,
+	},
+	.group = {
+		.attrs = rave_sp_rdu2_attrs,
+	},
+	.init = rave_sp_rdu2_init,
+};
+
+static const struct of_device_id rave_sp_dt_ids[] = {
+	{ .compatible = COMPATIBLE_RAVE_SP_NIU,  .data = &rave_sp_legacy },
+	{ .compatible = COMPATIBLE_RAVE_SP_MEZZ, .data = &rave_sp_legacy },
+	{ .compatible = COMPATIBLE_RAVE_SP_ESB,  .data = &rave_sp_legacy },
+	{ .compatible = COMPATIBLE_RAVE_SP_RDU1, .data = &rave_sp_rdu1   },
+	{ .compatible = COMPATIBLE_RAVE_SP_RDU2, .data = &rave_sp_rdu2   },
+	{ /* sentinel */ }
+};
+
+static const struct serdev_device_ops rave_sp_serdev_device_ops = {
+	.receive_buf  = rave_sp_receive_buf,
+	.write_wakeup = serdev_device_write_wakeup,
+};
+
+static int rave_sp_probe(struct serdev_device *serdev)
+{
+	struct device *dev = &serdev->dev;
+	const char *unknown = "unknown\n";
+	struct rave_sp *sp;
+	u32 baud;
+	int ret;
+
+	if (of_property_read_u32(dev->of_node, "current-speed", &baud)) {
+		dev_err(dev,
+			"'current-speed' is not specified in device node\n");
+		return -EINVAL;
+	}
+
+	sp = devm_kzalloc(dev, sizeof(*sp), GFP_KERNEL);
+	if (!sp)
+		return -ENOMEM;
+
+	sp->serdev = serdev;
+	dev_set_drvdata(dev, sp);
+
+	sp->variant = of_device_get_match_data(dev);
+	if (!sp->variant)
+		return -ENODEV;
+
+	mutex_init(&sp->bus_lock);
+	mutex_init(&sp->reply_lock);
+	BLOCKING_INIT_NOTIFIER_HEAD(&sp->event_notifier_list);
+
+	serdev_device_set_client_ops(serdev, &rave_sp_serdev_device_ops);
+	ret = serdev_device_open(serdev);
+	if (ret)
+		return ret;
+
+	serdev_device_set_baudrate(serdev, baud);
+
+	sp->silicon_devid		= unknown;
+	sp->silicon_devrev		= unknown;
+	sp->copper_rev_deb		= unknown;
+	sp->copper_rev_rmb		= unknown;
+	sp->copper_mod_deb		= unknown;
+	sp->copper_mod_rmb		= unknown;
+	sp->reset_reason		= unknown;
+	sp->part_number_firmware	= unknown;
+	sp->part_number_bootloader	= unknown;
+
+	sp->variant->init(sp);
+
+	/*
+	 * Those strings already have a \n embedded so no need to have
+	 * one in format string.
+	 */
+	dev_info(dev, "Firmware version: %s", sp->part_number_firmware);
+	dev_info(dev, "Bootloader version: %s", sp->part_number_bootloader);
+
+	rave_sp_load_reset_reason(sp);
+	rave_sp_load_silicon_rev(sp);
+
+	ret = devm_rave_sysfs_create_group(sp);
+	if (ret) {
+		serdev_device_close(serdev);
+		return ret;
+	}
+
+	return of_platform_default_populate(dev->of_node, NULL, dev);
+}
+
+static void rave_sp_remove(struct serdev_device *serdev)
+{
+	of_platform_depopulate(&serdev->dev);
+	serdev_device_close(serdev);
+}
+
+MODULE_DEVICE_TABLE(of, rave_sp_dt_ids);
+
+static struct serdev_device_driver rave_sp_drv = {
+	.probe			= rave_sp_probe,
+	.remove			= rave_sp_remove,
+	.driver = {
+		.name		= KBUILD_MODNAME,
+		.of_match_table	= rave_sp_dt_ids,
+	},
+};
+module_serdev_device_driver(rave_sp_drv);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Andrey Vostrikov <andrey.vostrikov@cogentembedded.com>");
+MODULE_AUTHOR("Nikita Yushchenko <nikita.yoush@cogentembedded.com>");
+MODULE_AUTHOR("Andrey Smirnov <andrew.smirnov@gmail.com>");
+MODULE_DESCRIPTION("RAVE SP core driver");
diff --git a/include/linux/rave-sp.h b/include/linux/rave-sp.h
new file mode 100644
index 000000000000..fe3bc5015161
--- /dev/null
+++ b/include/linux/rave-sp.h
@@ -0,0 +1,54 @@
+#ifndef _LINUX_RAVE_SP_H_
+#define _LINUX_RAVE_SP_H_
+
+enum rave_sp_command {
+	RAVE_SP_CMD_GET_FIRMWARE_VERSION	= 0x20,
+	RAVE_SP_CMD_GET_BOOTLOADER_VERSION	= 0x21,
+	RAVE_SP_CMD_BOOT_SOURCE			= 0x26,
+	RAVE_SP_CMD_GET_BOARD_COPPER_REV	= 0x2B,
+	RAVE_SP_CMD_GET_GPIO_STATE		= 0x2F,
+
+	RAVE_SP_CMD_STATUS			= 0xA0,
+	RAVE_SP_CMD_SW_WDT			= 0xA1,
+	RAVE_SP_CMD_PET_WDT			= 0xA2,
+	RAVE_SP_CMD_RESET			= 0xA7,
+	RAVE_SP_CMD_RESET_REASON		= 0xA8,
+
+	RAVE_SP_CMD_REQ_COPPER_REV		= 0xB6,
+	RAVE_SP_CMD_GET_I2C_DEVICE_STATUS	= 0xBA,
+	RAVE_SP_CMD_GET_SP_SILICON_REV		= 0xB9,
+	RAVE_SP_CMD_CONTROL_EVENTS		= 0xBB,
+
+	RAVE_SP_EVNT_BASE			= 0xE0,
+};
+
+struct rave_sp;
+
+static inline unsigned long rave_sp_action_pack(u8 event, u8 value)
+{
+	return ((unsigned long)value << 8) | event;
+}
+
+static inline u8 rave_sp_action_unpack_event(unsigned long action)
+{
+	return action & 0xff;
+}
+
+static inline u8 rave_sp_action_unpack_value(unsigned long action)
+{
+	return (action >> 8) & 0xff;
+}
+
+int rave_sp_exec(struct rave_sp *sp,
+		 void *__data,  size_t data_size,
+		 void *reply_data, size_t reply_data_size);
+int devm_rave_sp_register_event_notifier(struct device *dev,
+				     struct notifier_block *nb);
+
+#define COMPATIBLE_RAVE_SP_NIU		"zii,rave-sp-niu"
+#define COMPATIBLE_RAVE_SP_MEZZ		"zii,rave-sp-mezz"
+#define COMPATIBLE_RAVE_SP_ESB		"zii,rave-sp-esb"
+#define COMPATIBLE_RAVE_SP_RDU1		"zii,rave-sp-rdu1"
+#define COMPATIBLE_RAVE_SP_RDU2		"zii,rave-sp-rdu2"
+
+#endif /* _LINUX_RAVE_SP_H_ */
-- 
2.13.3

^ permalink raw reply related	[flat|nested] 9+ messages in thread

* [PATCH v3 2/2] dt-bindings: mfd: Add bindings for ZII RAVE devices
  2017-07-24 15:09 [PATCH v3 0/2] ZII RAVE platform driver Andrey Smirnov
  2017-07-24 15:09 ` [PATCH v3 1/2] platform: Add driver for RAVE Supervisory Processor Andrey Smirnov
@ 2017-07-24 15:09 ` Andrey Smirnov
  2017-07-24 16:23   ` Rob Herring
  1 sibling, 1 reply; 9+ messages in thread
From: Andrey Smirnov @ 2017-07-24 15:09 UTC (permalink / raw)
  To: linux-kernel
  Cc: Andrey Smirnov, cphealy, Lucas Stach, Nikita Yushchenko,
	Rob Herring, Mark Rutland, devicetree

Cc: cphealy@gmail.com
Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: Nikita Yushchenko <nikita.yoush@cogentembedded.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: devicetree@vger.kernel.org
Acked-for-MFD-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
---
 .../devicetree/bindings/mfd/zii,rave-sp.txt        | 39 ++++++++++++++++++++++
 1 file changed, 39 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mfd/zii,rave-sp.txt

diff --git a/Documentation/devicetree/bindings/mfd/zii,rave-sp.txt b/Documentation/devicetree/bindings/mfd/zii,rave-sp.txt
new file mode 100644
index 000000000000..088eff9ddb78
--- /dev/null
+++ b/Documentation/devicetree/bindings/mfd/zii,rave-sp.txt
@@ -0,0 +1,39 @@
+Zodiac Inflight Innovations RAVE Supervisory Processor
+
+RAVE Supervisory Processor communicates with SoC over UART. It is
+expected that its Device Tree node is specified as a child of a node
+corresponding to UART controller used for communication.
+
+Required parent device properties:
+
+ - compatible: Should be one of:
+	- "zii,rave-sp-niu"
+	- "zii,rave-sp-mezz"
+	- "zii,rave-sp-esb"
+	- "zii,rave-sp-rdu1"
+	- "zii,rave-sp-rdu2"
+
+ - current-speed: Should be set to baud rate SP device is using
+
+RAVE SP consists of the following sub-devices:
+
+Device				 Description
+------				 -----------
+rave-sp-wdt			: Watchdog
+rave-sp-nvmem			: Interface to onborad EEPROM
+rave-sp-backlight		: Display backlight
+rave-sp-hwmon			: Interface to onboard hardware sensors
+rave-sp-leds			: Interface to onboard LEDs
+rave-sp-input			: Interface to onboard power button
+
+Example of usage:
+
+	rdu {
+		compatible = "zii,rave-sp-rdu2";
+		current-speed = <1000000>;
+
+		watchdog {
+			compatible = "zii,rave-sp-watchdog";
+		};
+	};
+
-- 
2.13.3

^ permalink raw reply related	[flat|nested] 9+ messages in thread

* Re: [PATCH v3 2/2] dt-bindings: mfd: Add bindings for ZII RAVE devices
  2017-07-24 15:09 ` [PATCH v3 2/2] dt-bindings: mfd: Add bindings for ZII RAVE devices Andrey Smirnov
@ 2017-07-24 16:23   ` Rob Herring
  2017-07-24 19:34     ` Andrey Smirnov
  0 siblings, 1 reply; 9+ messages in thread
From: Rob Herring @ 2017-07-24 16:23 UTC (permalink / raw)
  To: Andrey Smirnov
  Cc: linux-kernel, cphealy, Lucas Stach, Nikita Yushchenko,
	Mark Rutland, devicetree

On Mon, Jul 24, 2017 at 08:09:15AM -0700, Andrey Smirnov wrote:
> Cc: cphealy@gmail.com
> Cc: Lucas Stach <l.stach@pengutronix.de>
> Cc: Nikita Yushchenko <nikita.yoush@cogentembedded.com>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: Mark Rutland <mark.rutland@arm.com>
> Cc: devicetree@vger.kernel.org
> Acked-for-MFD-by: Lee Jones <lee.jones@linaro.org>
> Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
> ---
>  .../devicetree/bindings/mfd/zii,rave-sp.txt        | 39 ++++++++++++++++++++++
>  1 file changed, 39 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/mfd/zii,rave-sp.txt

What happened to my ack?

Rob

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH v3 1/2] platform: Add driver for RAVE Supervisory Processor
  2017-07-24 15:09 ` [PATCH v3 1/2] platform: Add driver for RAVE Supervisory Processor Andrey Smirnov
@ 2017-07-24 17:25   ` Andy Shevchenko
  2017-07-24 19:53     ` Andrey Smirnov
  0 siblings, 1 reply; 9+ messages in thread
From: Andy Shevchenko @ 2017-07-24 17:25 UTC (permalink / raw)
  To: Andrey Smirnov; +Cc: linux-kernel, Chris Healy, Lucas Stach, Nikita Yushchenko

On Mon, Jul 24, 2017 at 6:09 PM, Andrey Smirnov
<andrew.smirnov@gmail.com> wrote:
> Add a driver for RAVE Supervisory Processor, an MCU implementing
> varoius bits of housekeeping functionality (watchdoging, backlight
> control, LED control, etc) on RAVE family of products by Zodiac
> Inflight Innovations.
>
> This driver implementes core MFD/serdev device as well as
> communication subroutines necessary for commanding the device.

Thanks for an update!

My (minor) comments below (most of them are related to spelling issues).

> +#define RAVE_SP_RX_BUFFER_SIZE         (RAVE_SP_MAX_DATA_SIZE + \
> +                                        RAVE_SP_CHECKSUM_SIZE)

Slightly better style is

#define RAVE_SP_RX_BUFFER_SIZE         \
    (RAVE_SP_MAX_DATA_SIZE + RAVE_SP_CHECKSUM_SIZE)

> +#define RAVE_SP_TX_BUFFER_SIZE         (RAVE_SP_STX_ETX_SIZE + \
> +                                        2 * RAVE_SP_RX_BUFFER_SIZE)

Ditto.

> +/**
> + * enum rave_sp_deframer_state - Possible state for de-framer
> + *
> + * @RAVE_SP_EXPECT_SOF:         scanning data stream for start of frame
> + *                              marker

One line?

> + * @RAVE_SP_EXPECT_DATA:        start of frame marker detected, collecting
> + *                              frame

Ditto

> + * @RAVE_SP_EXPECT_ESCAPED_DATA: escape character received, collecting
> + *                              escaped byte

Ditto.

> + */

> +/**
> + * struct rave_sp_variant_cmds - Variant specific command vtable
> + *
> + * @translate: Subroutine to translate common command identifiers to
> + *            device specific variants. Different generations of the
> + *            ICD employed different numberical constants to

Typo: numerical

> + *            represent same/similar commands and this function is
> + *            there to address that.
> + *
> + * @get_boot_source: Variant dependent implementaion of "get boot
> + *                  source" operation

Typo implementation

> + * @set_boot_source: Variant dependent implementaion of "set boot
> + *                  source" operation

Ditto.

Field descriptions are supposed to be _short_.

> + */

> +/**
> + * struct rave_sp_variant - RAVE supervisory processor core variant
> + *
> + * @checksum:  Variant specific checksum implementation
> + * @cmd:       Variant specific command vtable

Decode vtable.

> + * @init:      Variant specific initialization sequence implementation
> + * @group:     Attrubute group for exposed sysfs entries

Run spell checker over the file, please.

> + */

> + * @part_number_firmware:
> + * @part_number_bootloader:
> + * @reset_reason:
> + * @copper_rev_rmb:
> + * @copper_rev_deb:
> + * @silicon_devid:
> + * @silicon_devrev:
> + * @copper_mod_rmb:
> + * @copper_mod_deb:

???

> + *
> + * @variant:                   Device variant specific parameters and
> + *                             functions
> + * @event_notifier_list:       Input event notification chain (used with
> + *                             corresponding input MFD cell driver)

Make them _short_.

> + * @group:                     Attrubute group for exposed sysfs entries
> + *
> + *
> + * part_number_*, reset_reason, copper_*, and silicon_* fields are all

> + * strings retrived from the device during device probing and made
> + * availible for later userspace consumption via sysfs

Spell checker.

> + *
> + */

> +int devm_rave_sp_register_event_notifier(struct device *dev,
> +                                        struct notifier_block *nb)
> +{
> +       struct rave_sp *sp = dev_get_drvdata(dev->parent);
> +       struct notifier_block **rcnb;
> +       int ret;
> +
> +       rcnb = devres_alloc(rave_sp_unregister_event_notifier,
> +                           sizeof(*rcnb), GFP_KERNEL);
> +       if (!rcnb)
> +               return -ENOMEM;
> +
> +       ret = blocking_notifier_chain_register(&sp->event_notifier_list, nb);
> +       if (!ret) {
> +               *rcnb = nb;
> +               devres_add(dev, rcnb);
> +       } else {
> +               devres_free(rcnb);
> +       }
> +
> +       return ret;
> +}
> +EXPORT_SYMBOL_GPL(devm_rave_sp_register_event_notifier);

Did I miss

 EXPORT_SYMBOL_GPL(devm_rave_sp_unregister_event_notifier);

?

> +static const char *devm_rave_sp_version(struct device *dev, const char *buf)
> +{
> +       /*
> +        * NOTE: Ther format string below uses %02d to display u16
> +        * intentionally for the sake of backwards compatibility with
> +        * legacy software.
> +        */
> +       return devm_kasprintf(dev, GFP_KERNEL, "%02d%02d%02d.%c%c\n",
> +                             buf[0], le16_to_cpup((const __le16 *)&buf[1]),
> +                             buf[3], buf[4], buf[5]);
> +}

One more question about le16_to_cpup() use. Is the variable in the
buffer guaranteed to be always in little endian format?
Okay, looks like it's protocol which is little endian. Ok.

By the way, here it might be needed to call get_unaligned().

> +static ssize_t
> +i2c_device_status_show(struct device *dev,
> +                   struct device_attribute *attr,
> +                   char *buf)
> +{
> +       ssize_t ret;
> +       struct rave_sp *sp = dev_get_drvdata(dev);
> +       u8 status[2];
> +       u8 cmd[] = {
> +               [0] = RAVE_SP_CMD_GET_I2C_DEVICE_STATUS,
> +               [1] = 0
> +       };
> +
> +       ret = rave_sp_exec(sp, cmd, sizeof(cmd), &status, sizeof(status));
> +       if (ret < 0)
> +               return ret;
> +
> +       return sprintf(buf, "%04x\n", le16_to_cpup((__le16 *)status));
> +}

Ditto.

> +static int rave_sp_write(struct rave_sp *sp, const u8 *data, u8 data_size)
> +{

> +       size_t length;

Slightly better to put this line after *dest definition.

> +       const size_t checksum_length = sp->variant->checksum->length;
> +       unsigned char crc[checksum_length];
> +       unsigned char frame[RAVE_SP_TX_BUFFER_SIZE];
> +       unsigned char *dest = frame;

> +static u8 rave_sp_reply_code(u8 command)
> +{
> +       /*

> +        * There isn't a signle rule that describes command code ->

Typo: single.

> +        * ACK code transformation, but, going through various
> +        * versions of ICDs, there appear to be three distinct groups
> +        * that can be described by simple transformation.
> +        */

> +       switch (command) {
> +       case 0xA0 ... 0xBE:
> +               /*
> +                * Commands implemented by firmware found in RDU1 and
> +                * older devices all seem to obey the following rule
> +                */
> +               return command + 0x20;
> +       case 0xE0 ... 0xEF:
> +               /*
> +                * Events emitted by all version of the firmare use
> +                * least signifiact bit to get an ACK code

Typos.

> +                */
> +               return command | 0x01;
> +       default:
> +               /*
> +                * Commands implemented by firmware found in RDU2 are
> +                * similar to "old" commands, but they use slightly
> +                * different offset
> +                */
> +               return command + 0x40;
> +       }
> +}

> +
> +int rave_sp_exec(struct rave_sp *sp,
> +                void *__data,  size_t data_size,
> +                void *reply_data, size_t reply_data_size)
> +{
> +       int ret = 0;
> +       unsigned char *data = __data;
> +       const u8 ackid = (u8)atomic_inc_return(&sp->ackid);
> +       const int command = sp->variant->cmd.translate(data[0]);
> +       struct rave_sp_reply reply = {
> +               .code     = rave_sp_reply_code((u8)command),
> +               .ackid    = ackid,
> +               .data     = reply_data,
> +               .length   = reply_data_size,
> +               .received = COMPLETION_INITIALIZER_ONSTACK(reply.received),
> +       };
> +

> +       if (command < 0)
> +               return command;


Shouldn't be like

      command = sp->variant->cmd.translate(data[0]);
      if (command < 0)
              return command;

      reply.code = rave_sp_reply_code((u8)command);

?

> +
> +       mutex_lock(&sp->bus_lock);
> +
> +       mutex_lock(&sp->reply_lock);
> +       sp->reply = &reply;
> +       mutex_unlock(&sp->reply_lock);
> +

> +       data[0] = (u8)command;

unsigned char implies u8.

> +       data[1] = ackid;
> +
> +       rave_sp_write(sp, data, data_size);
> +
> +       if (!wait_for_completion_timeout(&reply.received, HZ)) {
> +               dev_err(&sp->serdev->dev, "Command timeout\n");
> +               ret = -ETIMEDOUT;
> +
> +               mutex_lock(&sp->reply_lock);
> +               sp->reply = NULL;
> +               mutex_unlock(&sp->reply_lock);
> +       }
> +
> +       mutex_unlock(&sp->bus_lock);
> +       return ret;
> +}

> +static int rave_sp_rdu2_cmd_translate(enum rave_sp_command command)
> +{
> +       if (command >= RAVE_SP_CMD_GET_FIRMWARE_VERSION &&
> +           command <= RAVE_SP_CMD_GET_GPIO_STATE)
> +               return command;
> +

> +       if (command == RAVE_SP_CMD_REQ_COPPER_REV)
> +               return 0x28;

Comment for use magic values?
Definition for it?

> +
> +       return rave_sp_rdu1_cmd_translate(command);
> +}

> +static int rave_sp_default_cmd_translate(enum rave_sp_command command)
> +{
> +       switch (command) {
> +       case RAVE_SP_CMD_GET_FIRMWARE_VERSION:
> +               return 0x11;
> +       case RAVE_SP_CMD_GET_BOOTLOADER_VERSION:
> +               return 0x12;
> +       case RAVE_SP_CMD_BOOT_SOURCE:
> +               return 0x14;
> +       case RAVE_SP_CMD_SW_WDT:
> +               return 0x1C;
> +       case RAVE_SP_CMD_RESET:
> +               return 0x1E;
> +       case RAVE_SP_CMD_RESET_REASON:
> +               return 0x1F;

Ditto.

> +       default:
> +               return -EINVAL;
> +       }
> +}

> +static const char *rave_sp_silicon_to_string(struct device *dev,
> +                                            const __le32 *version)
> +{
> +       return devm_kasprintf(dev, GFP_KERNEL, "%08x\n", le32_to_cpup(version));

I don't see why you can't use version value instead of pointer.

> +}

> +static const char *rave_sp_copper_to_string(struct device *dev, uint8_t version)
> +{
> +       return devm_kasprintf(dev, GFP_KERNEL, "%02x\n", version);
> +}
> +
> +

Remove extra empty line.

> +       .driver = {
> +               .name           = KBUILD_MODNAME,

This is bad idea. It might be someone can use a platform driver (as
part of MFD, for example) and someone else rename driver at some
point.
I understand that in practice it's quite unlikely, though better not
to put potential issues in the first place.

> +               .of_match_table = rave_sp_dt_ids,
> +       },

> +static inline u8 rave_sp_action_unpack_event(unsigned long action)
> +{
> +       return action & 0xff;
> +}
> +
> +static inline u8 rave_sp_action_unpack_value(unsigned long action)
> +{
> +       return (action >> 8) & 0xff;
> +}

You can drop & 0xff in both cases as it's implied by u8.

-- 
With Best Regards,
Andy Shevchenko

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH v3 2/2] dt-bindings: mfd: Add bindings for ZII RAVE devices
  2017-07-24 16:23   ` Rob Herring
@ 2017-07-24 19:34     ` Andrey Smirnov
  0 siblings, 0 replies; 9+ messages in thread
From: Andrey Smirnov @ 2017-07-24 19:34 UTC (permalink / raw)
  To: Rob Herring
  Cc: linux-kernel, Chris Healy, Lucas Stach, Nikita Yushchenko,
	Mark Rutland, devicetree

On Mon, Jul 24, 2017 at 9:23 AM, Rob Herring <robh@kernel.org> wrote:
> On Mon, Jul 24, 2017 at 08:09:15AM -0700, Andrey Smirnov wrote:
>> Cc: cphealy@gmail.com
>> Cc: Lucas Stach <l.stach@pengutronix.de>
>> Cc: Nikita Yushchenko <nikita.yoush@cogentembedded.com>
>> Cc: Rob Herring <robh+dt@kernel.org>
>> Cc: Mark Rutland <mark.rutland@arm.com>
>> Cc: devicetree@vger.kernel.org
>> Acked-for-MFD-by: Lee Jones <lee.jones@linaro.org>
>> Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
>> ---
>>  .../devicetree/bindings/mfd/zii,rave-sp.txt        | 39 ++++++++++++++++++++++
>>  1 file changed, 39 insertions(+)
>>  create mode 100644 Documentation/devicetree/bindings/mfd/zii,rave-sp.txt
>
> What happened to my ack?

Somehow I lost it, sorry about that. Will put it back in v4.

Thanks,
Andrey Smirnov

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH v3 1/2] platform: Add driver for RAVE Supervisory Processor
  2017-07-24 17:25   ` Andy Shevchenko
@ 2017-07-24 19:53     ` Andrey Smirnov
  2017-07-25 10:25       ` Andy Shevchenko
  0 siblings, 1 reply; 9+ messages in thread
From: Andrey Smirnov @ 2017-07-24 19:53 UTC (permalink / raw)
  To: Andy Shevchenko; +Cc: linux-kernel, Chris Healy, Lucas Stach, Nikita Yushchenko

On Mon, Jul 24, 2017 at 10:25 AM, Andy Shevchenko
<andy.shevchenko@gmail.com> wrote:
> On Mon, Jul 24, 2017 at 6:09 PM, Andrey Smirnov
> <andrew.smirnov@gmail.com> wrote:
>> Add a driver for RAVE Supervisory Processor, an MCU implementing
>> varoius bits of housekeeping functionality (watchdoging, backlight
>> control, LED control, etc) on RAVE family of products by Zodiac
>> Inflight Innovations.
>>
>> This driver implementes core MFD/serdev device as well as
>> communication subroutines necessary for commanding the device.
>
> Thanks for an update!
>
> My (minor) comments below (most of them are related to spelling issues).
>
>> +#define RAVE_SP_RX_BUFFER_SIZE         (RAVE_SP_MAX_DATA_SIZE + \
>> +                                        RAVE_SP_CHECKSUM_SIZE)
>
> Slightly better style is

>
> #define RAVE_SP_RX_BUFFER_SIZE         \
>     (RAVE_SP_MAX_DATA_SIZE + RAVE_SP_CHECKSUM_SIZE)
>
>> +#define RAVE_SP_TX_BUFFER_SIZE         (RAVE_SP_STX_ETX_SIZE + \
>> +                                        2 * RAVE_SP_RX_BUFFER_SIZE)
>
> Ditto.

Sure, will fix in v4.

>
>> +/**
>> + * enum rave_sp_deframer_state - Possible state for de-framer
>> + *
>> + * @RAVE_SP_EXPECT_SOF:         scanning data stream for start of frame
>> + *                              marker
>
> One line?
>
>> + * @RAVE_SP_EXPECT_DATA:        start of frame marker detected, collecting
>> + *                              frame
>
> Ditto
>
>> + * @RAVE_SP_EXPECT_ESCAPED_DATA: escape character received, collecting
>> + *                              escaped byte
>
> Ditto.

Sure. Will do in v4.

>
>> + */
>
>> +/**
>> + * struct rave_sp_variant_cmds - Variant specific command vtable
>> + *
>> + * @translate: Subroutine to translate common command identifiers to
>> + *            device specific variants. Different generations of the
>> + *            ICD employed different numberical constants to
>
> Typo: numerical
>
>> + *            represent same/similar commands and this function is
>> + *            there to address that.
>> + *
>> + * @get_boot_source: Variant dependent implementaion of "get boot
>> + *                  source" operation
>
> Typo implementation
>
>> + * @set_boot_source: Variant dependent implementaion of "set boot
>> + *                  source" operation
>
> Ditto.
>
> Field descriptions are supposed to be _short_.
>
>> + */
>
>> +/**
>> + * struct rave_sp_variant - RAVE supervisory processor core variant
>> + *
>> + * @checksum:  Variant specific checksum implementation
>> + * @cmd:       Variant specific command vtable
>
> Decode vtable.
>
>> + * @init:      Variant specific initialization sequence implementation
>> + * @group:     Attrubute group for exposed sysfs entries
>
> Run spell checker over the file, please.
>

Hmm, could've sworn I had it as a my pre-commit hook, but it looks
like I didn't. Will do in v4.

>> + */
>
>> + * @part_number_firmware:
>> + * @part_number_bootloader:
>> + * @reset_reason:
>> + * @copper_rev_rmb:
>> + * @copper_rev_deb:
>> + * @silicon_devid:
>> + * @silicon_devrev:
>> + * @copper_mod_rmb:
>> + * @copper_mod_deb:
>
> ???
>

That's my interpretation of you advice to describe those fields in
detailed comment below.

>> + *
>> + * @variant:                   Device variant specific parameters and
>> + *                             functions
>> + * @event_notifier_list:       Input event notification chain (used with
>> + *                             corresponding input MFD cell driver)
>
> Make them _short_.

OK, will do in v4.

>
>> + * @group:                     Attrubute group for exposed sysfs entries
>> + *
>> + *
>> + * part_number_*, reset_reason, copper_*, and silicon_* fields are all
>
>> + * strings retrived from the device during device probing and made
>> + * availible for later userspace consumption via sysfs
>
> Spell checker.
>

Ditto.

>> + *
>> + */
>
>> +int devm_rave_sp_register_event_notifier(struct device *dev,
>> +                                        struct notifier_block *nb)
>> +{
>> +       struct rave_sp *sp = dev_get_drvdata(dev->parent);
>> +       struct notifier_block **rcnb;
>> +       int ret;
>> +
>> +       rcnb = devres_alloc(rave_sp_unregister_event_notifier,
>> +                           sizeof(*rcnb), GFP_KERNEL);
>> +       if (!rcnb)
>> +               return -ENOMEM;
>> +
>> +       ret = blocking_notifier_chain_register(&sp->event_notifier_list, nb);
>> +       if (!ret) {
>> +               *rcnb = nb;
>> +               devres_add(dev, rcnb);
>> +       } else {
>> +               devres_free(rcnb);
>> +       }
>> +
>> +       return ret;
>> +}
>> +EXPORT_SYMBOL_GPL(devm_rave_sp_register_event_notifier);
>
> Did I miss
>
>  EXPORT_SYMBOL_GPL(devm_rave_sp_unregister_event_notifier);
>
> ?

No, you did not, as I mentioned in my reply for v2 to you, there's no
use-case for having that function, there's only one MFD-cell driver
that calls devm_rave_sp_register_event_notifier() and it does so as
the last step of its probe(), so there's not going to be any users of
devm_rave_sp_unregister_event_notifier().

>
>> +static const char *devm_rave_sp_version(struct device *dev, const char *buf)
>> +{
>> +       /*
>> +        * NOTE: Ther format string below uses %02d to display u16
>> +        * intentionally for the sake of backwards compatibility with
>> +        * legacy software.
>> +        */
>> +       return devm_kasprintf(dev, GFP_KERNEL, "%02d%02d%02d.%c%c\n",
>> +                             buf[0], le16_to_cpup((const __le16 *)&buf[1]),
>> +                             buf[3], buf[4], buf[5]);
>> +}
>
> One more question about le16_to_cpup() use. Is the variable in the
> buffer guaranteed to be always in little endian format?
> Okay, looks like it's protocol which is little endian. Ok.
>
> By the way, here it might be needed to call get_unaligned().
>

Sure, I'll add that just in case.

>> +static ssize_t
>> +i2c_device_status_show(struct device *dev,
>> +                   struct device_attribute *attr,
>> +                   char *buf)
>> +{
>> +       ssize_t ret;
>> +       struct rave_sp *sp = dev_get_drvdata(dev);
>> +       u8 status[2];
>> +       u8 cmd[] = {
>> +               [0] = RAVE_SP_CMD_GET_I2C_DEVICE_STATUS,
>> +               [1] = 0
>> +       };
>> +
>> +       ret = rave_sp_exec(sp, cmd, sizeof(cmd), &status, sizeof(status));
>> +       if (ret < 0)
>> +               return ret;
>> +
>> +       return sprintf(buf, "%04x\n", le16_to_cpup((__le16 *)status));
>> +}
>
> Ditto.
>

Will add in v4.

>> +static int rave_sp_write(struct rave_sp *sp, const u8 *data, u8 data_size)
>> +{
>
>> +       size_t length;
>
> Slightly better to put this line after *dest definition.
>

OK, coming in v4.

>> +       const size_t checksum_length = sp->variant->checksum->length;
>> +       unsigned char crc[checksum_length];
>> +       unsigned char frame[RAVE_SP_TX_BUFFER_SIZE];
>> +       unsigned char *dest = frame;
>
>> +static u8 rave_sp_reply_code(u8 command)
>> +{
>> +       /*
>
>> +        * There isn't a signle rule that describes command code ->
>
> Typo: single.
>
>> +        * ACK code transformation, but, going through various
>> +        * versions of ICDs, there appear to be three distinct groups
>> +        * that can be described by simple transformation.
>> +        */
>
>> +       switch (command) {
>> +       case 0xA0 ... 0xBE:
>> +               /*
>> +                * Commands implemented by firmware found in RDU1 and
>> +                * older devices all seem to obey the following rule
>> +                */
>> +               return command + 0x20;
>> +       case 0xE0 ... 0xEF:
>> +               /*
>> +                * Events emitted by all version of the firmare use
>> +                * least signifiact bit to get an ACK code
>
> Typos.
>

Will fix in v4.

>> +                */
>> +               return command | 0x01;
>> +       default:
>> +               /*
>> +                * Commands implemented by firmware found in RDU2 are
>> +                * similar to "old" commands, but they use slightly
>> +                * different offset
>> +                */
>> +               return command + 0x40;
>> +       }
>> +}
>
>> +
>> +int rave_sp_exec(struct rave_sp *sp,
>> +                void *__data,  size_t data_size,
>> +                void *reply_data, size_t reply_data_size)
>> +{
>> +       int ret = 0;
>> +       unsigned char *data = __data;
>> +       const u8 ackid = (u8)atomic_inc_return(&sp->ackid);
>> +       const int command = sp->variant->cmd.translate(data[0]);
>> +       struct rave_sp_reply reply = {
>> +               .code     = rave_sp_reply_code((u8)command),
>> +               .ackid    = ackid,
>> +               .data     = reply_data,
>> +               .length   = reply_data_size,
>> +               .received = COMPLETION_INITIALIZER_ONSTACK(reply.received),
>> +       };
>> +
>
>> +       if (command < 0)
>> +               return command;
>
>
> Shouldn't be like
>
>       command = sp->variant->cmd.translate(data[0]);
>       if (command < 0)
>               return command;
>
>       reply.code = rave_sp_reply_code((u8)command);
>
> ?

Shouldn't really make any difference, rave_sp_reply_code() will either
return -EINVAL or some ACK code but in either case it would not be
used due to early return on "command" being less that 0.

>
>> +
>> +       mutex_lock(&sp->bus_lock);
>> +
>> +       mutex_lock(&sp->reply_lock);
>> +       sp->reply = &reply;
>> +       mutex_unlock(&sp->reply_lock);
>> +
>
>> +       data[0] = (u8)command;
>
> unsigned char implies u8.

Fair point. Will remove the typecast.

>
>> +       data[1] = ackid;
>> +
>> +       rave_sp_write(sp, data, data_size);
>> +
>> +       if (!wait_for_completion_timeout(&reply.received, HZ)) {
>> +               dev_err(&sp->serdev->dev, "Command timeout\n");
>> +               ret = -ETIMEDOUT;
>> +
>> +               mutex_lock(&sp->reply_lock);
>> +               sp->reply = NULL;
>> +               mutex_unlock(&sp->reply_lock);
>> +       }
>> +
>> +       mutex_unlock(&sp->bus_lock);
>> +       return ret;
>> +}
>
>> +static int rave_sp_rdu2_cmd_translate(enum rave_sp_command command)
>> +{
>> +       if (command >= RAVE_SP_CMD_GET_FIRMWARE_VERSION &&
>> +           command <= RAVE_SP_CMD_GET_GPIO_STATE)
>> +               return command;
>> +
>
>> +       if (command == RAVE_SP_CMD_REQ_COPPER_REV)
>> +               return 0x28;
>
> Comment for use magic values?
> Definition for it?
>
>> +
>> +       return rave_sp_rdu1_cmd_translate(command);
>> +}
>
>> +static int rave_sp_default_cmd_translate(enum rave_sp_command command)
>> +{
>> +       switch (command) {
>> +       case RAVE_SP_CMD_GET_FIRMWARE_VERSION:
>> +               return 0x11;
>> +       case RAVE_SP_CMD_GET_BOOTLOADER_VERSION:
>> +               return 0x12;
>> +       case RAVE_SP_CMD_BOOT_SOURCE:
>> +               return 0x14;
>> +       case RAVE_SP_CMD_SW_WDT:
>> +               return 0x1C;
>> +       case RAVE_SP_CMD_RESET:
>> +               return 0x1E;
>> +       case RAVE_SP_CMD_RESET_REASON:
>> +               return 0x1F;
>
> Ditto.

I'll add comment explaining the origin of the magic values.

>
>> +       default:
>> +               return -EINVAL;
>> +       }
>> +}
>
>> +static const char *rave_sp_silicon_to_string(struct device *dev,
>> +                                            const __le32 *version)
>> +{
>> +       return devm_kasprintf(dev, GFP_KERNEL, "%08x\n", le32_to_cpup(version));
>
> I don't see why you can't use version value instead of pointer.
>

Sure, I can do that.

>> +}
>
>> +static const char *rave_sp_copper_to_string(struct device *dev, uint8_t version)
>> +{
>> +       return devm_kasprintf(dev, GFP_KERNEL, "%02x\n", version);
>> +}
>> +
>> +
>
> Remove extra empty line.
>
>> +       .driver = {
>> +               .name           = KBUILD_MODNAME,
>
> This is bad idea. It might be someone can use a platform driver (as
> part of MFD, for example) and someone else rename driver at some
> point.
> I understand that in practice it's quite unlikely, though better not
> to put potential issues in the first place.
>

Sure, I can convert it to a explicit string.

>> +               .of_match_table = rave_sp_dt_ids,
>> +       },
>
>> +static inline u8 rave_sp_action_unpack_event(unsigned long action)
>> +{
>> +       return action & 0xff;
>> +}
>> +
>> +static inline u8 rave_sp_action_unpack_value(unsigned long action)
>> +{
>> +       return (action >> 8) & 0xff;
>> +}
>
> You can drop & 0xff in both cases as it's implied by u8.
>

Will remove in v4.

Thanks,
Andrey Smirnov

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH v3 1/2] platform: Add driver for RAVE Supervisory Processor
  2017-07-24 19:53     ` Andrey Smirnov
@ 2017-07-25 10:25       ` Andy Shevchenko
  2017-07-25 12:37         ` Andrey Smirnov
  0 siblings, 1 reply; 9+ messages in thread
From: Andy Shevchenko @ 2017-07-25 10:25 UTC (permalink / raw)
  To: Andrey Smirnov; +Cc: linux-kernel, Chris Healy, Lucas Stach, Nikita Yushchenko

On Mon, Jul 24, 2017 at 10:53 PM, Andrey Smirnov
<andrew.smirnov@gmail.com> wrote:
> On Mon, Jul 24, 2017 at 10:25 AM, Andy Shevchenko
> <andy.shevchenko@gmail.com> wrote:
>> On Mon, Jul 24, 2017 at 6:09 PM, Andrey Smirnov
>> <andrew.smirnov@gmail.com> wrote:

>> Field descriptions are supposed to be _short_.

>>> + * @part_number_firmware:
>>> + * @part_number_bootloader:
>>> + * @reset_reason:
>>> + * @copper_rev_rmb:
>>> + * @copper_rev_deb:
>>> + * @silicon_devid:
>>> + * @silicon_devrev:
>>> + * @copper_mod_rmb:
>>> + * @copper_mod_deb:
>>
>> ???

> That's my interpretation of you advice to describe those fields in
> detailed comment below.

Put there short descriptions and explain them in details (if you want
to) below. Don't leave them blank.

>>> +int devm_rave_sp_register_event_notifier(struct device *dev,
>>> +                                        struct notifier_block *nb)
>>> +{
>>> +       struct rave_sp *sp = dev_get_drvdata(dev->parent);
>>> +       struct notifier_block **rcnb;
>>> +       int ret;
>>> +
>>> +       rcnb = devres_alloc(rave_sp_unregister_event_notifier,
>>> +                           sizeof(*rcnb), GFP_KERNEL);
>>> +       if (!rcnb)
>>> +               return -ENOMEM;
>>> +
>>> +       ret = blocking_notifier_chain_register(&sp->event_notifier_list, nb);
>>> +       if (!ret) {
>>> +               *rcnb = nb;
>>> +               devres_add(dev, rcnb);
>>> +       } else {
>>> +               devres_free(rcnb);
>>> +       }
>>> +
>>> +       return ret;
>>> +}
>>> +EXPORT_SYMBOL_GPL(devm_rave_sp_register_event_notifier);
>>
>> Did I miss
>>
>>  EXPORT_SYMBOL_GPL(devm_rave_sp_unregister_event_notifier);
>>
>> ?
>
> No, you did not, as I mentioned in my reply for v2 to you, there's no
> use-case for having that function, there's only one MFD-cell driver
> that calls devm_rave_sp_register_event_notifier() and it does so as
> the last step of its probe(), so there's not going to be any users of
> devm_rave_sp_unregister_event_notifier().

Ok.

>>> +static const char *devm_rave_sp_version(struct device *dev, const char *buf)
>>> +{
>>> +       /*
>>> +        * NOTE: Ther format string below uses %02d to display u16
>>> +        * intentionally for the sake of backwards compatibility with
>>> +        * legacy software.
>>> +        */
>>> +       return devm_kasprintf(dev, GFP_KERNEL, "%02d%02d%02d.%c%c\n",
>>> +                             buf[0], le16_to_cpup((const __le16 *)&buf[1]),
>>> +                             buf[3], buf[4], buf[5]);
>>> +}
>>
>> One more question about le16_to_cpup() use. Is the variable in the
>> buffer guaranteed to be always in little endian format?
>> Okay, looks like it's protocol which is little endian. Ok.
>>
>> By the way, here it might be needed to call get_unaligned().
>>
>
> Sure, I'll add that just in case.

He-h, "just in case" is not good enough :-) I would like you
understand why that might be needed.

When you run on platforms that have issues with unaligned access you
might get weird behaviour. To prevent such we have helpers.

>>> +int rave_sp_exec(struct rave_sp *sp,
>>> +                void *__data,  size_t data_size,
>>> +                void *reply_data, size_t reply_data_size)
>>> +{
>>> +       int ret = 0;
>>> +       unsigned char *data = __data;
>>> +       const u8 ackid = (u8)atomic_inc_return(&sp->ackid);
>>> +       const int command = sp->variant->cmd.translate(data[0]);
>>> +       struct rave_sp_reply reply = {
>>> +               .code     = rave_sp_reply_code((u8)command),
>>> +               .ackid    = ackid,
>>> +               .data     = reply_data,
>>> +               .length   = reply_data_size,
>>> +               .received = COMPLETION_INITIALIZER_ONSTACK(reply.received),
>>> +       };
>>> +
>>
>>> +       if (command < 0)
>>> +               return command;
>>
>>
>> Shouldn't be like
>>
>>       command = sp->variant->cmd.translate(data[0]);
>>       if (command < 0)
>>               return command;
>>
>>       reply.code = rave_sp_reply_code((u8)command);
>>
>> ?
>
> Shouldn't really make any difference, rave_sp_reply_code() will either
> return -EINVAL or some ACK code but in either case it would not be
> used due to early return on "command" being less that 0.

So, why then run a code that will be thrown away?

-- 
With Best Regards,
Andy Shevchenko

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH v3 1/2] platform: Add driver for RAVE Supervisory Processor
  2017-07-25 10:25       ` Andy Shevchenko
@ 2017-07-25 12:37         ` Andrey Smirnov
  0 siblings, 0 replies; 9+ messages in thread
From: Andrey Smirnov @ 2017-07-25 12:37 UTC (permalink / raw)
  To: Andy Shevchenko; +Cc: linux-kernel, Chris Healy, Lucas Stach, Nikita Yushchenko

On Tue, Jul 25, 2017 at 3:25 AM, Andy Shevchenko
<andy.shevchenko@gmail.com> wrote:
> On Mon, Jul 24, 2017 at 10:53 PM, Andrey Smirnov
> <andrew.smirnov@gmail.com> wrote:
>> On Mon, Jul 24, 2017 at 10:25 AM, Andy Shevchenko
>> <andy.shevchenko@gmail.com> wrote:
>>> On Mon, Jul 24, 2017 at 6:09 PM, Andrey Smirnov
>>> <andrew.smirnov@gmail.com> wrote:
>
>>> Field descriptions are supposed to be _short_.
>
>>>> + * @part_number_firmware:
>>>> + * @part_number_bootloader:
>>>> + * @reset_reason:
>>>> + * @copper_rev_rmb:
>>>> + * @copper_rev_deb:
>>>> + * @silicon_devid:
>>>> + * @silicon_devrev:
>>>> + * @copper_mod_rmb:
>>>> + * @copper_mod_deb:
>>>
>>> ???
>
>> That's my interpretation of you advice to describe those fields in
>> detailed comment below.
>
> Put there short descriptions and explain them in details (if you want
> to) below. Don't leave them blank.
>

OK.

>>>> +int devm_rave_sp_register_event_notifier(struct device *dev,
>>>> +                                        struct notifier_block *nb)
>>>> +{
>>>> +       struct rave_sp *sp = dev_get_drvdata(dev->parent);
>>>> +       struct notifier_block **rcnb;
>>>> +       int ret;
>>>> +
>>>> +       rcnb = devres_alloc(rave_sp_unregister_event_notifier,
>>>> +                           sizeof(*rcnb), GFP_KERNEL);
>>>> +       if (!rcnb)
>>>> +               return -ENOMEM;
>>>> +
>>>> +       ret = blocking_notifier_chain_register(&sp->event_notifier_list, nb);
>>>> +       if (!ret) {
>>>> +               *rcnb = nb;
>>>> +               devres_add(dev, rcnb);
>>>> +       } else {
>>>> +               devres_free(rcnb);
>>>> +       }
>>>> +
>>>> +       return ret;
>>>> +}
>>>> +EXPORT_SYMBOL_GPL(devm_rave_sp_register_event_notifier);
>>>
>>> Did I miss
>>>
>>>  EXPORT_SYMBOL_GPL(devm_rave_sp_unregister_event_notifier);
>>>
>>> ?
>>
>> No, you did not, as I mentioned in my reply for v2 to you, there's no
>> use-case for having that function, there's only one MFD-cell driver
>> that calls devm_rave_sp_register_event_notifier() and it does so as
>> the last step of its probe(), so there's not going to be any users of
>> devm_rave_sp_unregister_event_notifier().
>
> Ok.
>
>>>> +static const char *devm_rave_sp_version(struct device *dev, const char *buf)
>>>> +{
>>>> +       /*
>>>> +        * NOTE: Ther format string below uses %02d to display u16
>>>> +        * intentionally for the sake of backwards compatibility with
>>>> +        * legacy software.
>>>> +        */
>>>> +       return devm_kasprintf(dev, GFP_KERNEL, "%02d%02d%02d.%c%c\n",
>>>> +                             buf[0], le16_to_cpup((const __le16 *)&buf[1]),
>>>> +                             buf[3], buf[4], buf[5]);
>>>> +}
>>>
>>> One more question about le16_to_cpup() use. Is the variable in the
>>> buffer guaranteed to be always in little endian format?
>>> Okay, looks like it's protocol which is little endian. Ok.
>>>
>>> By the way, here it might be needed to call get_unaligned().
>>>
>>
>> Sure, I'll add that just in case.
>
> He-h, "just in case" is not good enough :-) I would like you
> understand why that might be needed.
>
> When you run on platforms that have issues with unaligned access you
> might get weird behaviour. To prevent such we have helpers.
>

I understand the purpose of get_unaligned(). The reason I say "just in
case" is because such platforms don't really exist in practice. All of
the devices that ship with RAVE SP MCUs on-board are ARMv7A based CPUs
which should be capable of performing unaligned access.

>>>> +int rave_sp_exec(struct rave_sp *sp,
>>>> +                void *__data,  size_t data_size,
>>>> +                void *reply_data, size_t reply_data_size)
>>>> +{
>>>> +       int ret = 0;
>>>> +       unsigned char *data = __data;
>>>> +       const u8 ackid = (u8)atomic_inc_return(&sp->ackid);
>>>> +       const int command = sp->variant->cmd.translate(data[0]);
>>>> +       struct rave_sp_reply reply = {
>>>> +               .code     = rave_sp_reply_code((u8)command),
>>>> +               .ackid    = ackid,
>>>> +               .data     = reply_data,
>>>> +               .length   = reply_data_size,
>>>> +               .received = COMPLETION_INITIALIZER_ONSTACK(reply.received),
>>>> +       };
>>>> +
>>>
>>>> +       if (command < 0)
>>>> +               return command;
>>>
>>>
>>> Shouldn't be like
>>>
>>>       command = sp->variant->cmd.translate(data[0]);
>>>       if (command < 0)
>>>               return command;
>>>
>>>       reply.code = rave_sp_reply_code((u8)command);
>>>
>>> ?
>>
>> Shouldn't really make any difference, rave_sp_reply_code() will either
>> return -EINVAL or some ACK code but in either case it would not be
>> used due to early return on "command" being less that 0.
>
> So, why then run a code that will be thrown away?
>

Because this way "reply" is initialized in a single place instead of
that code being spread around.

Thanks,
Andrey Smirnov

^ permalink raw reply	[flat|nested] 9+ messages in thread

end of thread, other threads:[~2017-07-25 12:37 UTC | newest]

Thread overview: 9+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2017-07-24 15:09 [PATCH v3 0/2] ZII RAVE platform driver Andrey Smirnov
2017-07-24 15:09 ` [PATCH v3 1/2] platform: Add driver for RAVE Supervisory Processor Andrey Smirnov
2017-07-24 17:25   ` Andy Shevchenko
2017-07-24 19:53     ` Andrey Smirnov
2017-07-25 10:25       ` Andy Shevchenko
2017-07-25 12:37         ` Andrey Smirnov
2017-07-24 15:09 ` [PATCH v3 2/2] dt-bindings: mfd: Add bindings for ZII RAVE devices Andrey Smirnov
2017-07-24 16:23   ` Rob Herring
2017-07-24 19:34     ` Andrey Smirnov

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