[PATCH v3 0/3] siox: add support for new bus type

[PATCH v3 0/3] siox: add support for new bus type

[Uwe Kleine-König]

Hello,

this is v3 of the series to add support for Eckelmann's SIOX bus to the kernel.

I dropped patch 1 as Greg already applied that. Patch 1 (which was patch 2
before) just got a cast in two locations that are necessary on 64bit architecures where
sizeof(size_t) != sizeof(int).

Uwe Kleine-König (3):
  siox: add support for tracing
  siox: add gpio bus driver
  MAINTAINERS: Add entry for SIOX

 .../bindings/siox/eckelmann,siox-gpio.txt          |  19 +++
 .../devicetree/bindings/vendor-prefixes.txt        |   1 +
 MAINTAINERS                                        |   7 +
 drivers/siox/Kconfig                               |   9 ++
 drivers/siox/Makefile                              |   1 +
 drivers/siox/siox-bus-gpio.c                       | 172 +++++++++++++++++++++
 drivers/siox/siox-core.c                           |  12 ++
 include/trace/events/siox.h                        |  66 ++++++++
 8 files changed, 287 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/siox/eckelmann,siox-gpio.txt
 create mode 100644 drivers/siox/siox-bus-gpio.c
 create mode 100644 include/trace/events/siox.h

-- 
2.11.0

[PATCH v3 1/3] siox: add support for tracing

[Uwe Kleine-König]

Implement tracing for SIOX. There are events for the data that is
written to the bus and for data being read from it.

Acked-by: Gavin Schenk <g.schenk@eckelmann.de>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---

Notes:
    
    Changes since v1, sent with Message-Id: 20171207093008.20688-3-u.kleine-koenig@pengutronix.de:
    
     - drop a WARN_ON
     - Added Steven Rostedt to Cc: now that the first patch is expected to stay
       more or less as it is.
    
    Changes since v2, sent with Message-Id: 20171218165910.10577-3-u.kleine-koenig@pengutronix.de:
    
     - Add a cast to fix a build warning on 64bit archs

 drivers/siox/siox-core.c    | 12 +++++++++
 include/trace/events/siox.h | 66 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 78 insertions(+)
 create mode 100644 include/trace/events/siox.h

diff --git a/drivers/siox/siox-core.c b/drivers/siox/siox-core.c
index 16585c1b2b9e..fdfcdea25867 100644
--- a/drivers/siox/siox-core.c
+++ b/drivers/siox/siox-core.c
@@ -33,6 +33,9 @@
  */
 #define SIOX_STATUS_TYPE		0xf0
 
+#define CREATE_TRACE_POINTS
+#include <trace/events/siox.h>
+
 static bool siox_is_registered;
 
 static void siox_master_lock(struct siox_master *smaster)
@@ -126,6 +129,7 @@ static void siox_poll(struct siox_master *smaster)
 {
 	struct siox_device *sdevice;
 	size_t i = smaster->setbuf_len;
+	unsigned int devno = 0;
 	int unsync_error = 0;
 
 	smaster->last_poll = jiffies;
@@ -172,6 +176,10 @@ static void siox_poll(struct siox_master *smaster)
 			sdevice->status_written &= ~SIOX_STATUS_WDG;
 
 		smaster->buf[i] = sdevice->status_written;
+
+		trace_siox_set_data(smaster, sdevice, devno, i);
+
+		devno++;
 	}
 
 	smaster->pushpull(smaster, smaster->setbuf_len, smaster->buf,
@@ -181,6 +189,7 @@ static void siox_poll(struct siox_master *smaster)
 	unsync_error = 0;
 
 	/* interpret data pulled in from devices in buf[setbuf_len..] */
+	devno = 0;
 	i = smaster->setbuf_len;
 	list_for_each_entry(sdevice, &smaster->devices, node) {
 		struct siox_driver *sdriver =
@@ -255,10 +264,13 @@ static void siox_poll(struct siox_master *smaster)
 		sdevice->status_written_lastcycle = sdevice->status_written;
 		sdevice->connected = connected;
 
+		trace_siox_get_data(smaster, sdevice, devno, status_clean, i);
+
 		/* only give data read to driver if the device is connected */
 		if (sdriver && connected)
 			sdriver->get_data(sdevice, &smaster->buf[i]);
 
+		devno++;
 		i += sdevice->outbytes;
 	}
 }
diff --git a/include/trace/events/siox.h b/include/trace/events/siox.h
new file mode 100644
index 000000000000..68a43fc2c3a5
--- /dev/null
+++ b/include/trace/events/siox.h
@@ -0,0 +1,66 @@
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM siox
+
+#if !defined(_TRACE_SIOX_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_SIOX_H
+
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(siox_set_data,
+	    TP_PROTO(const struct siox_master *smaster,
+		     const struct siox_device *sdevice,
+		     unsigned int devno, size_t bufoffset),
+	    TP_ARGS(smaster, sdevice, devno, bufoffset),
+	    TP_STRUCT__entry(
+			     __field(int, busno)
+			     __field(unsigned int, devno)
+			     __field(size_t, inbytes)
+			     __dynamic_array(u8, buf, sdevice->inbytes)
+			    ),
+	    TP_fast_assign(
+			   __entry->busno = smaster->busno;
+			   __entry->devno = devno;
+			   __entry->inbytes = sdevice->inbytes;
+			   memcpy(__get_dynamic_array(buf),
+				  smaster->buf + bufoffset, sdevice->inbytes);
+			  ),
+	    TP_printk("siox-%d-%u [%*phD]",
+		      __entry->busno,
+		      __entry->devno,
+		      (int)__entry->inbytes, __get_dynamic_array(buf)
+		     )
+);
+
+TRACE_EVENT(siox_get_data,
+	    TP_PROTO(const struct siox_master *smaster,
+		     const struct siox_device *sdevice,
+		     unsigned int devno, u8 status_clean,
+		     size_t bufoffset),
+	    TP_ARGS(smaster, sdevice, devno, status_clean, bufoffset),
+	    TP_STRUCT__entry(
+			     __field(int, busno)
+			     __field(unsigned int, devno)
+			     __field(u8, status_clean)
+			     __field(size_t, outbytes)
+			     __dynamic_array(u8, buf, sdevice->outbytes)
+			    ),
+	    TP_fast_assign(
+			   __entry->busno = smaster->busno;
+			   __entry->devno = devno;
+			   __entry->status_clean = status_clean;
+			   __entry->outbytes = sdevice->outbytes;
+			   memcpy(__get_dynamic_array(buf),
+				  smaster->buf + bufoffset, sdevice->outbytes);
+			  ),
+	    TP_printk("siox-%d-%u (%02hhx) [%*phD]",
+		      __entry->busno,
+		      __entry->devno,
+		      __entry->status_clean,
+		      (int)__entry->outbytes, __get_dynamic_array(buf)
+		     )
+);
+
+#endif /* if !defined(_TRACE_SIOX_H) || defined(TRACE_HEADER_MULTI_READ) */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>
-- 
2.11.0

[PATCH v3 2/3] siox: add gpio bus driver

[Uwe Kleine-König]

This bus driver uses GPIOs to control the four SIOX bus lines.

Acked-by: Gavin Schenk <g.schenk@eckelmann.de>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---

Notes:
    No changes since v1, sent with Message-Id: 20171207093008.20688-4-u.kleine-koenig@pengutronix.de
    No changes since v2, sent with Message-Id: 20171218165910.10577-4-u.kleine-koenig@pengutronix.de

 .../bindings/siox/eckelmann,siox-gpio.txt          |  19 +++
 .../devicetree/bindings/vendor-prefixes.txt        |   1 +
 drivers/siox/Kconfig                               |   9 ++
 drivers/siox/Makefile                              |   1 +
 drivers/siox/siox-bus-gpio.c                       | 172 +++++++++++++++++++++
 5 files changed, 202 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/siox/eckelmann,siox-gpio.txt
 create mode 100644 drivers/siox/siox-bus-gpio.c

diff --git a/Documentation/devicetree/bindings/siox/eckelmann,siox-gpio.txt b/Documentation/devicetree/bindings/siox/eckelmann,siox-gpio.txt
new file mode 100644
index 000000000000..55259cf39c25
--- /dev/null
+++ b/Documentation/devicetree/bindings/siox/eckelmann,siox-gpio.txt
@@ -0,0 +1,19 @@
+Eckelmann SIOX GPIO bus
+
+Required properties:
+- compatible : "eckelmann,siox-gpio"
+- din-gpios, dout-gpios, dclk-gpios, dld-gpios: references gpios for the
+    corresponding bus signals.
+
+Examples:
+
+        siox {
+                compatible = "eckelmann,siox-gpio";
+                pinctrl-names = "default";
+                pinctrl-0 = <&pinctrl_siox>;
+
+                din-gpios = <&gpio6 11 0>;
+                dout-gpios = <&gpio6 8 0>;
+                dclk-gpios = <&gpio6 9 0>;
+                dld-gpios = <&gpio6 10 0>;
+        };
diff --git a/Documentation/devicetree/bindings/vendor-prefixes.txt b/Documentation/devicetree/bindings/vendor-prefixes.txt
index 0994bdd82cd3..889d1c0f5050 100644
--- a/Documentation/devicetree/bindings/vendor-prefixes.txt
+++ b/Documentation/devicetree/bindings/vendor-prefixes.txt
@@ -97,6 +97,7 @@ dptechnics	DPTechnics
 dragino	Dragino Technology Co., Limited
 ea	Embedded Artists AB
 ebv	EBV Elektronik
+eckelmann	Eckelmann AG
 edt	Emerging Display Technologies
 eeti	eGalax_eMPIA Technology Inc
 elan	Elan Microelectronic Corp.
diff --git a/drivers/siox/Kconfig b/drivers/siox/Kconfig
index bd24d9b50dc6..083d2e62189a 100644
--- a/drivers/siox/Kconfig
+++ b/drivers/siox/Kconfig
@@ -7,3 +7,12 @@ menuconfig SIOX
 	  to drive additional I/O units.
 
 	  Unless you know better, it is probably safe to say "no" here.
+
+if SIOX
+
+config SIOX_BUS_GPIO
+	tristate "SIOX GPIO bus driver"
+	help
+	  SIOX bus driver that controls the four bus lines using GPIOs.
+
+endif
diff --git a/drivers/siox/Makefile b/drivers/siox/Makefile
index d55cb5e08868..a956f65206d5 100644
--- a/drivers/siox/Makefile
+++ b/drivers/siox/Makefile
@@ -1 +1,2 @@
 obj-$(CONFIG_SIOX) += siox-core.o
+obj-$(CONFIG_SIOX_BUS_GPIO) += siox-bus-gpio.o
diff --git a/drivers/siox/siox-bus-gpio.c b/drivers/siox/siox-bus-gpio.c
new file mode 100644
index 000000000000..ea7ef982968b
--- /dev/null
+++ b/drivers/siox/siox-bus-gpio.c
@@ -0,0 +1,172 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2015-2017 Pengutronix, Uwe Kleine-König <kernel@pengutronix.de>
+ */
+
+#include <linux/gpio/consumer.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+#include <linux/delay.h>
+
+#include "siox.h"
+
+#define DRIVER_NAME "siox-gpio"
+
+struct siox_gpio_ddata {
+	struct gpio_desc *din;
+	struct gpio_desc *dout;
+	struct gpio_desc *dclk;
+	struct gpio_desc *dld;
+};
+
+static unsigned int siox_clkhigh_ns = 1000;
+static unsigned int siox_loadhigh_ns;
+static unsigned int siox_bytegap_ns;
+
+static int siox_gpio_pushpull(struct siox_master *smaster,
+			      size_t setbuf_len, const u8 setbuf[],
+			      size_t getbuf_len, u8 getbuf[])
+{
+	struct siox_gpio_ddata *ddata = siox_master_get_devdata(smaster);
+	size_t i;
+	size_t cycles = max(setbuf_len, getbuf_len);
+
+	/* reset data and clock */
+	gpiod_set_value_cansleep(ddata->dout, 0);
+	gpiod_set_value_cansleep(ddata->dclk, 0);
+
+	gpiod_set_value_cansleep(ddata->dld, 1);
+	ndelay(siox_loadhigh_ns);
+	gpiod_set_value_cansleep(ddata->dld, 0);
+
+	for (i = 0; i < cycles; ++i) {
+		u8 set = 0, get = 0;
+		size_t j;
+
+		if (i >= cycles - setbuf_len)
+			set = setbuf[i - (cycles - setbuf_len)];
+
+		for (j = 0; j < 8; ++j) {
+			get <<= 1;
+			if (gpiod_get_value_cansleep(ddata->din))
+				get |= 1;
+
+			/* DOUT is logically inverted */
+			gpiod_set_value_cansleep(ddata->dout, !(set & 0x80));
+			set <<= 1;
+
+			gpiod_set_value_cansleep(ddata->dclk, 1);
+			ndelay(siox_clkhigh_ns);
+			gpiod_set_value_cansleep(ddata->dclk, 0);
+		}
+
+		if (i < getbuf_len)
+			getbuf[i] = get;
+
+		ndelay(siox_bytegap_ns);
+	}
+
+	gpiod_set_value_cansleep(ddata->dld, 1);
+	ndelay(siox_loadhigh_ns);
+	gpiod_set_value_cansleep(ddata->dld, 0);
+
+	/*
+	 * Resetting dout isn't necessary protocol wise, but it makes the
+	 * signals more pretty because the dout level is deterministic between
+	 * cycles. Note that this only affects dout between the master and the
+	 * first siox device. dout for the later devices depend on the output of
+	 * the previous siox device.
+	 */
+	gpiod_set_value_cansleep(ddata->dout, 0);
+
+	return 0;
+}
+
+static int siox_gpio_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct siox_gpio_ddata *ddata;
+	int ret;
+	struct siox_master *smaster;
+
+	smaster = siox_master_alloc(&pdev->dev, sizeof(*ddata));
+	if (!smaster) {
+		dev_err(dev, "failed to allocate siox master\n");
+		return -ENOMEM;
+	}
+
+	platform_set_drvdata(pdev, smaster);
+	ddata = siox_master_get_devdata(smaster);
+
+	ddata->din = devm_gpiod_get(dev, "din", GPIOD_IN);
+	if (IS_ERR(ddata->din)) {
+		ret = PTR_ERR(ddata->din);
+		dev_err(dev, "Failed to get %s GPIO: %d\n", "din", ret);
+		goto err;
+	}
+
+	ddata->dout = devm_gpiod_get(dev, "dout", GPIOD_OUT_LOW);
+	if (IS_ERR(ddata->dout)) {
+		ret = PTR_ERR(ddata->dout);
+		dev_err(dev, "Failed to get %s GPIO: %d\n", "dout", ret);
+		goto err;
+	}
+
+	ddata->dclk = devm_gpiod_get(dev, "dclk", GPIOD_OUT_LOW);
+	if (IS_ERR(ddata->dclk)) {
+		ret = PTR_ERR(ddata->dclk);
+		dev_err(dev, "Failed to get %s GPIO: %d\n", "dclk", ret);
+		goto err;
+	}
+
+	ddata->dld = devm_gpiod_get(dev, "dld", GPIOD_OUT_LOW);
+	if (IS_ERR(ddata->dld)) {
+		ret = PTR_ERR(ddata->dld);
+		dev_err(dev, "Failed to get %s GPIO: %d\n", "dld", ret);
+		goto err;
+	}
+
+	smaster->pushpull = siox_gpio_pushpull;
+	/* XXX: determine automatically like spi does */
+	smaster->busno = 0;
+
+	ret = siox_master_register(smaster);
+	if (ret) {
+		dev_err(dev, "Failed to register siox master: %d\n", ret);
+err:
+		siox_master_put(smaster);
+	}
+
+	return ret;
+}
+
+static int siox_gpio_remove(struct platform_device *pdev)
+{
+	struct siox_master *master = platform_get_drvdata(pdev);
+
+	siox_master_unregister(master);
+
+	return 0;
+}
+
+static const struct of_device_id siox_gpio_dt_ids[] = {
+	{ .compatible = "eckelmann,siox-gpio", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, siox_gpio_dt_ids);
+
+static struct platform_driver siox_gpio_driver = {
+	.probe = siox_gpio_probe,
+	.remove = siox_gpio_remove,
+
+	.driver = {
+		.name = DRIVER_NAME,
+		.of_match_table = siox_gpio_dt_ids,
+	},
+};
+module_platform_driver(siox_gpio_driver);
+
+MODULE_AUTHOR("Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:" DRIVER_NAME);
-- 
2.11.0

[PATCH v3 3/3] MAINTAINERS: Add entry for SIOX

[Uwe Kleine-König]

Maintenance is split between Gavin who works for Eckelmann and so has
the functional authority, knows the background and history of this bus
system and me who designed most of the actual code with the old
microcontroller code as reference.

Acked-by: Gavin Schenk <g.schenk@eckelmann.de>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---

Notes:
    Changes since v1, sent with Message-Id: 20171207093008.20688-6-u.kleine-koenig@pengutronix.de:
    
     - drop F: for gpio driver. The patch was dropped from the series because it
       has to go via another tree.
    
    No changes since v2, sent with Message-Id: 20171218165910.10577-5-u.kleine-koenig@pengutronix.de

 MAINTAINERS | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index aa71ab52fd76..9bb39c2e2ffb 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -12449,6 +12449,13 @@ F:	lib/siphash.c
 F:	lib/test_siphash.c
 F:	include/linux/siphash.h
 
+SIOX
+M:	Gavin Schenk <g.schenk@eckelmann.de>
+M:	Uwe Kleine-König <kernel@pengutronix.de>
+S:	Supported
+F:	drivers/siox/*
+F:	include/trace/events/siox.h
+
 SIS 190 ETHERNET DRIVER
 M:	Francois Romieu <romieu@fr.zoreil.com>
 L:	netdev@vger.kernel.org
-- 
2.11.0

Re: [PATCH v3 3/3] MAINTAINERS: Add entry for SIOX

[Joe Perches]

On Tue, 2017-12-19 at 10:00 +0100, Uwe Kleine-König wrote:
> Maintenance is split between Gavin who works for Eckelmann and so has
> the functional authority, knows the background and history of this bus
> system and me who designed most of the actual code with the old
> microcontroller code as reference.
[]
> diff --git a/MAINTAINERS b/MAINTAINERS
[]
> @@ -12449,6 +12449,13 @@ F:	lib/siphash.c
>  F:	lib/test_siphash.c
>  F:	include/linux/siphash.h
>  
> +SIOX
> +M:	Gavin Schenk <g.schenk@eckelmann.de>
> +M:	Uwe Kleine-König <kernel@pengutronix.de>
> +S:	Supported
> +F:	drivers/siox/*

Are you intending to only support files
files in drivers/siox and not support files
in any subdirectories of drivers/siox?

Re: [PATCH v3 3/3] MAINTAINERS: Add entry for SIOX

[Uwe Kleine-König]

On Tue, Dec 19, 2017 at 01:05:40AM -0800, Joe Perches wrote:
> On Tue, 2017-12-19 at 10:00 +0100, Uwe Kleine-König wrote:
> > Maintenance is split between Gavin who works for Eckelmann and so has
> > the functional authority, knows the background and history of this bus
> > system and me who designed most of the actual code with the old
> > microcontroller code as reference.
> []
> > diff --git a/MAINTAINERS b/MAINTAINERS
> []
> > @@ -12449,6 +12449,13 @@ F:	lib/siphash.c
> >  F:	lib/test_siphash.c
> >  F:	include/linux/siphash.h
> >  
> > +SIOX
> > +M:	Gavin Schenk <g.schenk@eckelmann.de>
> > +M:	Uwe Kleine-König <kernel@pengutronix.de>
> > +S:	Supported
> > +F:	drivers/siox/*
> 
> Are you intending to only support files
> files in drivers/siox and not support files
> in any subdirectories of drivers/siox?

I don't expect subdirectories to appear there. So I don't care much, but
if it's considered nice: I'd have to drop the * to
match everything under drivers/siox?

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |

Re: [PATCH v3 3/3] MAINTAINERS: Add entry for SIOX

[Joe Perches]

On Tue, 2017-12-19 at 11:12 +0100, Uwe Kleine-König wrote:
> On Tue, Dec 19, 2017 at 01:05:40AM -0800, Joe Perches wrote:
> > On Tue, 2017-12-19 at 10:00 +0100, Uwe Kleine-König wrote:
> > > Maintenance is split between Gavin who works for Eckelmann and so has
> > > the functional authority, knows the background and history of this bus
> > > system and me who designed most of the actual code with the old
> > > microcontroller code as reference.
> > 
> > []
> > > diff --git a/MAINTAINERS b/MAINTAINERS
> > 
> > []
> > > @@ -12449,6 +12449,13 @@ F:	lib/siphash.c
> > >  F:	lib/test_siphash.c
> > >  F:	include/linux/siphash.h
> > >  
> > > +SIOX
> > > +M:	Gavin Schenk <g.schenk@eckelmann.de>
> > > +M:	Uwe Kleine-König <kernel@pengutronix.de>
> > > +S:	Supported
> > > +F:	drivers/siox/*
> > 
> > Are you intending to only support files
> > files in drivers/siox and not support files
> > in any subdirectories of drivers/siox?
> 
> I don't expect subdirectories to appear there. So I don't care much, but
> if it's considered nice: I'd have to drop the * to
> match everything under drivers/siox?

Correct.