[PATCH 0/2] input: driver for RPi's official 7" touchscreen

[PATCH 0/2] input: driver for RPi's official 7" touchscreen

[Nicolas Saenz Julienne]

This small series adds support for Raspberry pi's 7" touchscreen. Which
alongside with the backlight driver are the last devices needed to have
a functional touchscreen upstream.

With this setup the board's VC4 firmware takes care of communicating
with the touch chip and provides data though a shared memory area
provided by the driver. The driver takes care of polling the firmware
whenever at around 60Hz since there is no interrupt line available.

The 1.0 revision of the touchscreen is based on the ft5426 chip.
Technically, with some changes in edt-ft54x4.c we should be able to
access the data directly through I2C. Yet this bus is meant to be owned
by RPi's firmware and might access it anytime. For example, to
configure RPi's camera device. As sharing the bus master interface is
not possible a series of alternatives have been tested unsuccessfully
[1]. It seems that we'll be unable to access the chip directly in a
"clean" way which leaves us with this firmware based solution.

The driver was rewritten based on the one available on the downstream
Raspberry Pi kernel tree: https://github.com/raspberrypi/linux/.

This series is based on v4.20-rc6 and was tested on a RPi 3 B+.

Changelog

RFC -> PATCH:
  - Better dependencies check in Kconfig
  - Add SPDX tag
  - Use polled input device API
  - Use input_mt_sync_frame()
  - Drop reference from dt node in probe
  - Use devm where possible
  - Small cosmetic changes

[1] https://lists.infradead.org/pipermail/linux-rpi-kernel/2018-December/008444.html
===

Nicolas Saenz Julienne (2):
  input: add official Raspberry Pi's touchscreen driver
  Input: raspberrypi-ts - add devicetree binding documentation

 .../touchscreen/raspberrypi,firmware-ts.txt   |  26 ++
 drivers/input/touchscreen/Kconfig             |  12 +
 drivers/input/touchscreen/Makefile            |   1 +
 drivers/input/touchscreen/raspberrypi-ts.c    | 223 ++++++++++++++++++
 4 files changed, 262 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/input/touchscreen/raspberrypi,firmware-ts.txt
 create mode 100644 drivers/input/touchscreen/raspberrypi-ts.c

-- 
2.19.2

[PATCH 1/2] input: add official Raspberry Pi's touchscreen driver

[Nicolas Saenz Julienne]

Add's support to Raspberry Pi's 7" Touch device. Instead of using a
conventional bus all information is copied into a memory mapped area by
RPi's firmware.

Based on the driver found in RPi's kernel repository.

Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
---
 drivers/input/touchscreen/Kconfig          |  12 ++
 drivers/input/touchscreen/Makefile         |   1 +
 drivers/input/touchscreen/raspberrypi-ts.c | 223 +++++++++++++++++++++
 3 files changed, 236 insertions(+)
 create mode 100644 drivers/input/touchscreen/raspberrypi-ts.c

diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index 2a80675cfd94..a9be434de738 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -696,6 +696,18 @@ config TOUCHSCREEN_EDT_FT5X06
 	  To compile this driver as a module, choose M here: the
 	  module will be called edt-ft5x06.
 
+config TOUCHSCREEN_RASPBERRYPI_TS
+	tristate "Raspberry Pi's firmware base touch screen support"
+	depends on RASPBERRYPI_FIRMWARE || COMPILE_TEST
+	help
+	  Say Y here if you have the offitial Raspberry Pi 7' scren on your
+	  system.
+
+	  If unsure, say N.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called raspberrypi-ts.
+
 config TOUCHSCREEN_MIGOR
 	tristate "Renesas MIGO-R touchscreen"
 	depends on (SH_MIGOR || COMPILE_TEST) && I2C
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index 5911a4190cd2..3eccb1925e89 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -109,3 +109,4 @@ obj-$(CONFIG_TOUCHSCREEN_ZET6223)	+= zet6223.o
 obj-$(CONFIG_TOUCHSCREEN_ZFORCE)	+= zforce_ts.o
 obj-$(CONFIG_TOUCHSCREEN_COLIBRI_VF50)	+= colibri-vf50-ts.o
 obj-$(CONFIG_TOUCHSCREEN_ROHM_BU21023)	+= rohm_bu21023.o
+obj-$(CONFIG_TOUCHSCREEN_RASPBERRYPI_TS)	+= raspberrypi-ts.o
diff --git a/drivers/input/touchscreen/raspberrypi-ts.c b/drivers/input/touchscreen/raspberrypi-ts.c
new file mode 100644
index 000000000000..edc92018687e
--- /dev/null
+++ b/drivers/input/touchscreen/raspberrypi-ts.c
@@ -0,0 +1,223 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Raspberry Pi 3 firmware based touchscreen driver
+ *
+ * Copyright (C) 2015, 2017 Raspberry Pi
+ * Copyright (C) 2018 Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
+ */
+
+#include <linux/io.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/bitops.h>
+#include <linux/dma-mapping.h>
+#include <linux/platform_device.h>
+#include <linux/input.h>
+#include <linux/input/mt.h>
+#include <linux/input-polldev.h>
+#include <linux/input/touchscreen.h>
+#include <soc/bcm2835/raspberrypi-firmware.h>
+
+#define RPI_TS_DEFAULT_WIDTH	800
+#define RPI_TS_DEFAULT_HEIGHT	480
+
+#define RPI_TS_MAX_SUPPORTED_POINTS	10
+
+#define RPI_TS_FTS_TOUCH_DOWN		0
+#define RPI_TS_FTS_TOUCH_CONTACT	2
+
+#define RPI_TS_POLL_INTERVAL		17	/* 60fps */
+
+struct rpi_ts {
+	struct platform_device *pdev;
+	struct input_polled_dev *poll_dev;
+	struct touchscreen_properties prop;
+
+	void __iomem *fw_regs_va;
+	dma_addr_t fw_regs_phys;
+
+	int known_ids;
+};
+
+struct rpi_ts_regs {
+	u8 device_mode;
+	u8 gesture_id;
+	u8 num_points;
+	struct rpi_ts_touch {
+		u8 xh;
+		u8 xl;
+		u8 yh;
+		u8 yl;
+		u8 pressure; /* Not supported */
+		u8 area;     /* Not supported */
+	} point[RPI_TS_MAX_SUPPORTED_POINTS];
+};
+
+/*
+ * We poll the memory based register copy of the touchscreen chip using the
+ * number of points register to know whether the copy has been updated (we
+ * write 99 to the memory copy, the GPU will write between 0 - 10 points)
+ */
+static void rpi_ts_poll(struct input_polled_dev *dev)
+{
+	struct input_dev *input = dev->input;
+	struct rpi_ts *ts = dev->private;
+	struct rpi_ts_regs regs;
+	int modified_ids = 0;
+	long released_ids;
+	int event_type;
+	int touchid;
+	int x, y;
+	int i;
+
+	memcpy_fromio(&regs, ts->fw_regs_va, sizeof(regs));
+	iowrite8(99, ts->fw_regs_va + offsetof(struct rpi_ts_regs, num_points));
+
+	if (regs.num_points == 99 ||
+	    (regs.num_points == 0 && ts->known_ids == 0))
+	    return;
+
+	for (i = 0; i < regs.num_points; i++) {
+		x = (((int)regs.point[i].xh & 0xf) << 8) + regs.point[i].xl;
+		y = (((int)regs.point[i].yh & 0xf) << 8) + regs.point[i].yl;
+		touchid = (regs.point[i].yh >> 4) & 0xf;
+		event_type = (regs.point[i].xh >> 6) & 0x03;
+
+		modified_ids |= BIT(touchid);
+
+		if (event_type == RPI_TS_FTS_TOUCH_DOWN ||
+		    event_type == RPI_TS_FTS_TOUCH_CONTACT) {
+			input_mt_slot(input, touchid);
+			input_mt_report_slot_state(input, MT_TOOL_FINGER, 1);
+			touchscreen_report_pos(input, &ts->prop, x, y, true);
+		}
+	}
+
+	released_ids = ts->known_ids & ~modified_ids;
+	for_each_set_bit(i, &released_ids, RPI_TS_MAX_SUPPORTED_POINTS) {
+		input_mt_slot(input, i);
+		input_mt_report_slot_state(input, MT_TOOL_FINGER, 0);
+		modified_ids &= ~(BIT(i));
+	}
+	ts->known_ids = modified_ids;
+
+	input_mt_sync_frame(input);
+	input_sync(input);
+}
+
+static void rpi_ts_dma_cleanup(void *data)
+{
+	struct rpi_ts *ts = data;
+	struct device *dev = &ts->pdev->dev;
+
+	if(ts->fw_regs_va)
+		dma_free_coherent(dev, PAGE_SIZE, ts->fw_regs_va,
+				  ts->fw_regs_phys);
+}
+
+static int rpi_ts_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct input_polled_dev *poll_dev;
+	struct device_node *fw_node;
+	struct rpi_firmware *fw;
+	struct input_dev *input;
+	struct rpi_ts *ts;
+	u32 touchbuf;
+	int ret;
+
+	fw_node = of_get_parent(np);
+	if (!fw_node) {
+		dev_err(dev, "Missing firmware node\n");
+		return -ENOENT;
+	}
+
+	fw = rpi_firmware_get(fw_node);
+	of_node_put(fw_node);
+	if (!fw)
+		return -EPROBE_DEFER;
+
+	ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
+	if (!ts) {
+		dev_err(dev, "Failed to allocate memory\n");
+		return -ENOMEM;
+	}
+	ts->pdev = pdev;
+
+	ret = devm_add_action_or_reset(dev, rpi_ts_dma_cleanup, ts);
+	if (ret)
+		return ret;
+
+	ts->fw_regs_va = dma_zalloc_coherent(dev, PAGE_SIZE, &ts->fw_regs_phys,
+					     GFP_KERNEL);
+	if (!ts->fw_regs_va) {
+		dev_err(dev, "failed to dma_alloc_coherent\n");
+		return -ENOMEM;
+	}
+
+	touchbuf = (u32)ts->fw_regs_phys;
+	ret = rpi_firmware_property(fw, RPI_FIRMWARE_FRAMEBUFFER_SET_TOUCHBUF,
+				    &touchbuf, sizeof(touchbuf));
+
+	if (ret || touchbuf != 0) {
+		dev_warn(dev, "Failed to set touchbuf, trying to get err:%x\n",
+			 ret);
+		return ret;
+	}
+
+	poll_dev = devm_input_allocate_polled_device(dev);
+	if (!poll_dev) {
+		dev_err(dev, "Failed to allocate input device\n");
+		return -ENOMEM;
+	}
+	ts->poll_dev = poll_dev;
+	input = poll_dev->input;
+
+	input->name = "raspberrypi-ts";
+	input->id.bustype = BUS_HOST;
+	poll_dev->poll_interval = RPI_TS_POLL_INTERVAL;
+	poll_dev->poll = rpi_ts_poll;
+	poll_dev->private = ts;
+
+	__set_bit(EV_SYN, input->evbit);
+	__set_bit(EV_KEY, input->evbit);
+	__set_bit(EV_ABS, input->evbit);
+
+	input_set_abs_params(input, ABS_MT_POSITION_X, 0,
+			     RPI_TS_DEFAULT_WIDTH, 0, 0);
+	input_set_abs_params(input, ABS_MT_POSITION_Y, 0,
+			     RPI_TS_DEFAULT_HEIGHT, 0, 0);
+	touchscreen_parse_properties(input, true, &ts->prop);
+
+	input_mt_init_slots(input, RPI_TS_MAX_SUPPORTED_POINTS,
+			    INPUT_MT_DIRECT | INPUT_MT_POINTER);
+
+	ret = input_register_polled_device(poll_dev);
+	if (ret) {
+		dev_err(dev, "could not register input device, %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static const struct of_device_id rpi_ts_match[] = {
+	{ .compatible = "raspberrypi,firmware-ts", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, rpi_ts_match);
+
+static struct platform_driver rpi_ts_driver = {
+	.driver = {
+		.name   = "raspberrypi-ts",
+		.of_match_table = rpi_ts_match,
+	},
+	.probe          = rpi_ts_probe,
+};
+module_platform_driver(rpi_ts_driver);
+
+MODULE_AUTHOR("Gordon Hollingworth");
+MODULE_AUTHOR("Nicolas Saenz Julienne <nsaenzjulienne@suse.de>");
+MODULE_DESCRIPTION("Raspberry Pi 3 firmware based touchscreen driver");
+MODULE_LICENSE("GPL v2");
-- 
2.19.2

[PATCH 2/2] Input: raspberrypi-ts - add devicetree binding documentation

[Nicolas Saenz Julienne]

Adds device tree documentation for Raspberry Pi's official 7"
touchscreen.

Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
---
 .../touchscreen/raspberrypi,firmware-ts.txt   | 26 +++++++++++++++++++
 1 file changed, 26 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/input/touchscreen/raspberrypi,firmware-ts.txt

diff --git a/Documentation/devicetree/bindings/input/touchscreen/raspberrypi,firmware-ts.txt b/Documentation/devicetree/bindings/input/touchscreen/raspberrypi,firmware-ts.txt
new file mode 100644
index 000000000000..38e22eb222e9
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/touchscreen/raspberrypi,firmware-ts.txt
@@ -0,0 +1,26 @@
+Raspberry Pi 3 firmware based 7" touchscreen
+=====================================
+
+Required properties:
+ - compatible: "raspberrypi,firmware-ts"
+
+Optional properties:
+ - firmware: Reference to RPi's firmware device node
+ - touchscreen-size-x: See touchscreen.txt
+ - touchscreen-size-y: See touchscreen.txt
+ - touchscreen-inverted-x: See touchscreen.txt
+ - touchscreen-inverted-y: See touchscreen.txt
+ - touchscreen-swapped-x-y: See touchscreen.txt
+
+Example:
+
+firmware: firmware-rpi {
+	compatible = "raspberrypi,bcm2835-firmware";
+	mboxes = <&mailbox>;
+
+	ts: touchscreen {
+		compatible = "raspberrypi,firmware-ts";
+		touchscreen-size-x = <800>;
+		touchscreen-size-y = <480>;
+	};
+};
-- 
2.19.2

Re: [PATCH 1/2] input: add official Raspberry Pi's touchscreen driver

[Dmitry Torokhov]

Hi Nicolas,

On Mon, Dec 10, 2018 at 05:30:20PM +0100, Nicolas Saenz Julienne wrote:
> Add's support to Raspberry Pi's 7" Touch device. Instead of using a
> conventional bus all information is copied into a memory mapped area by
> RPi's firmware.
> 
> Based on the driver found in RPi's kernel repository.

I believe we are almost there, just a couple of nits.

> 
> Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
> ---
>  drivers/input/touchscreen/Kconfig          |  12 ++
>  drivers/input/touchscreen/Makefile         |   1 +
>  drivers/input/touchscreen/raspberrypi-ts.c | 223 +++++++++++++++++++++
>  3 files changed, 236 insertions(+)
>  create mode 100644 drivers/input/touchscreen/raspberrypi-ts.c
> 
> diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
> index 2a80675cfd94..a9be434de738 100644
> --- a/drivers/input/touchscreen/Kconfig
> +++ b/drivers/input/touchscreen/Kconfig
> @@ -696,6 +696,18 @@ config TOUCHSCREEN_EDT_FT5X06
>  	  To compile this driver as a module, choose M here: the
>  	  module will be called edt-ft5x06.
>  
> +config TOUCHSCREEN_RASPBERRYPI_TS
> +	tristate "Raspberry Pi's firmware base touch screen support"
> +	depends on RASPBERRYPI_FIRMWARE || COMPILE_TEST
> +	help
> +	  Say Y here if you have the offitial Raspberry Pi 7' scren on your
> +	  system.
> +
> +	  If unsure, say N.
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called raspberrypi-ts.
> +
>  config TOUCHSCREEN_MIGOR
>  	tristate "Renesas MIGO-R touchscreen"
>  	depends on (SH_MIGOR || COMPILE_TEST) && I2C
> diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
> index 5911a4190cd2..3eccb1925e89 100644
> --- a/drivers/input/touchscreen/Makefile
> +++ b/drivers/input/touchscreen/Makefile
> @@ -109,3 +109,4 @@ obj-$(CONFIG_TOUCHSCREEN_ZET6223)	+= zet6223.o
>  obj-$(CONFIG_TOUCHSCREEN_ZFORCE)	+= zforce_ts.o
>  obj-$(CONFIG_TOUCHSCREEN_COLIBRI_VF50)	+= colibri-vf50-ts.o
>  obj-$(CONFIG_TOUCHSCREEN_ROHM_BU21023)	+= rohm_bu21023.o
> +obj-$(CONFIG_TOUCHSCREEN_RASPBERRYPI_TS)	+= raspberrypi-ts.o
> diff --git a/drivers/input/touchscreen/raspberrypi-ts.c b/drivers/input/touchscreen/raspberrypi-ts.c
> new file mode 100644
> index 000000000000..edc92018687e
> --- /dev/null
> +++ b/drivers/input/touchscreen/raspberrypi-ts.c
> @@ -0,0 +1,223 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Raspberry Pi 3 firmware based touchscreen driver
> + *
> + * Copyright (C) 2015, 2017 Raspberry Pi
> + * Copyright (C) 2018 Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
> + */
> +
> +#include <linux/io.h>
> +#include <linux/slab.h>
> +#include <linux/module.h>
> +#include <linux/bitops.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/platform_device.h>
> +#include <linux/input.h>
> +#include <linux/input/mt.h>
> +#include <linux/input-polldev.h>
> +#include <linux/input/touchscreen.h>
> +#include <soc/bcm2835/raspberrypi-firmware.h>
> +
> +#define RPI_TS_DEFAULT_WIDTH	800
> +#define RPI_TS_DEFAULT_HEIGHT	480
> +
> +#define RPI_TS_MAX_SUPPORTED_POINTS	10
> +
> +#define RPI_TS_FTS_TOUCH_DOWN		0
> +#define RPI_TS_FTS_TOUCH_CONTACT	2
> +
> +#define RPI_TS_POLL_INTERVAL		17	/* 60fps */
> +
> +struct rpi_ts {
> +	struct platform_device *pdev;
> +	struct input_polled_dev *poll_dev;
> +	struct touchscreen_properties prop;
> +
> +	void __iomem *fw_regs_va;
> +	dma_addr_t fw_regs_phys;
> +
> +	int known_ids;
> +};
> +
> +struct rpi_ts_regs {
> +	u8 device_mode;
> +	u8 gesture_id;
> +	u8 num_points;
> +	struct rpi_ts_touch {
> +		u8 xh;
> +		u8 xl;
> +		u8 yh;
> +		u8 yl;
> +		u8 pressure; /* Not supported */
> +		u8 area;     /* Not supported */
> +	} point[RPI_TS_MAX_SUPPORTED_POINTS];
> +};
> +
> +/*
> + * We poll the memory based register copy of the touchscreen chip using the
> + * number of points register to know whether the copy has been updated (we
> + * write 99 to the memory copy, the GPU will write between 0 - 10 points)
> + */
> +static void rpi_ts_poll(struct input_polled_dev *dev)
> +{
> +	struct input_dev *input = dev->input;
> +	struct rpi_ts *ts = dev->private;
> +	struct rpi_ts_regs regs;
> +	int modified_ids = 0;
> +	long released_ids;
> +	int event_type;
> +	int touchid;
> +	int x, y;
> +	int i;
> +
> +	memcpy_fromio(&regs, ts->fw_regs_va, sizeof(regs));
> +	iowrite8(99, ts->fw_regs_va + offsetof(struct rpi_ts_regs, num_points));
> +
> +	if (regs.num_points == 99 ||
> +	    (regs.num_points == 0 && ts->known_ids == 0))
> +	    return;
> +
> +	for (i = 0; i < regs.num_points; i++) {
> +		x = (((int)regs.point[i].xh & 0xf) << 8) + regs.point[i].xl;
> +		y = (((int)regs.point[i].yh & 0xf) << 8) + regs.point[i].yl;
> +		touchid = (regs.point[i].yh >> 4) & 0xf;
> +		event_type = (regs.point[i].xh >> 6) & 0x03;
> +
> +		modified_ids |= BIT(touchid);
> +
> +		if (event_type == RPI_TS_FTS_TOUCH_DOWN ||
> +		    event_type == RPI_TS_FTS_TOUCH_CONTACT) {
> +			input_mt_slot(input, touchid);
> +			input_mt_report_slot_state(input, MT_TOOL_FINGER, 1);
> +			touchscreen_report_pos(input, &ts->prop, x, y, true);
> +		}
> +	}
> +
> +	released_ids = ts->known_ids & ~modified_ids;
> +	for_each_set_bit(i, &released_ids, RPI_TS_MAX_SUPPORTED_POINTS) {
> +		input_mt_slot(input, i);
> +		input_mt_report_slot_state(input, MT_TOOL_FINGER, 0);
> +		modified_ids &= ~(BIT(i));
> +	}
> +	ts->known_ids = modified_ids;
> +
> +	input_mt_sync_frame(input);
> +	input_sync(input);
> +}
> +
> +static void rpi_ts_dma_cleanup(void *data)
> +{
> +	struct rpi_ts *ts = data;
> +	struct device *dev = &ts->pdev->dev;
> +
> +	if(ts->fw_regs_va)

Drop the condition.

> +		dma_free_coherent(dev, PAGE_SIZE, ts->fw_regs_va,
> +				  ts->fw_regs_phys);
> +}
> +
> +static int rpi_ts_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct device_node *np = dev->of_node;
> +	struct input_polled_dev *poll_dev;
> +	struct device_node *fw_node;
> +	struct rpi_firmware *fw;
> +	struct input_dev *input;
> +	struct rpi_ts *ts;
> +	u32 touchbuf;
> +	int ret;
> +
> +	fw_node = of_get_parent(np);
> +	if (!fw_node) {
> +		dev_err(dev, "Missing firmware node\n");
> +		return -ENOENT;
> +	}
> +
> +	fw = rpi_firmware_get(fw_node);
> +	of_node_put(fw_node);
> +	if (!fw)
> +		return -EPROBE_DEFER;
> +
> +	ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
> +	if (!ts) {
> +		dev_err(dev, "Failed to allocate memory\n");
> +		return -ENOMEM;
> +	}
> +	ts->pdev = pdev;
> +
> +	ret = devm_add_action_or_reset(dev, rpi_ts_dma_cleanup, ts);
> +	if (ret)
> +		return ret;

This call needs to be after dma_zalloc_coherent(). Also (my personal
preference) can we please call this variable "error"? Then we can write
"if (error) ...".

> +
> +	ts->fw_regs_va = dma_zalloc_coherent(dev, PAGE_SIZE, &ts->fw_regs_phys,
> +					     GFP_KERNEL);
> +	if (!ts->fw_regs_va) {
> +		dev_err(dev, "failed to dma_alloc_coherent\n");
> +		return -ENOMEM;
> +	}
> +
> +	touchbuf = (u32)ts->fw_regs_phys;
> +	ret = rpi_firmware_property(fw, RPI_FIRMWARE_FRAMEBUFFER_SET_TOUCHBUF,
> +				    &touchbuf, sizeof(touchbuf));
> +
> +	if (ret || touchbuf != 0) {
> +		dev_warn(dev, "Failed to set touchbuf, trying to get err:%x\n",
> +			 ret);
> +		return ret;
> +	}
> +
> +	poll_dev = devm_input_allocate_polled_device(dev);
> +	if (!poll_dev) {
> +		dev_err(dev, "Failed to allocate input device\n");
> +		return -ENOMEM;
> +	}
> +	ts->poll_dev = poll_dev;
> +	input = poll_dev->input;
> +
> +	input->name = "raspberrypi-ts";
> +	input->id.bustype = BUS_HOST;
> +	poll_dev->poll_interval = RPI_TS_POLL_INTERVAL;
> +	poll_dev->poll = rpi_ts_poll;
> +	poll_dev->private = ts;
> +
> +	__set_bit(EV_SYN, input->evbit);
> +	__set_bit(EV_KEY, input->evbit);
> +	__set_bit(EV_ABS, input->evbit);

No need to set these, EV_SYN is set by the input core, and KEY/ABS are
by input_set_abs_params() and input_mt_init_slots().

> +
> +	input_set_abs_params(input, ABS_MT_POSITION_X, 0,
> +			     RPI_TS_DEFAULT_WIDTH, 0, 0);
> +	input_set_abs_params(input, ABS_MT_POSITION_Y, 0,
> +			     RPI_TS_DEFAULT_HEIGHT, 0, 0);
> +	touchscreen_parse_properties(input, true, &ts->prop);
> +
> +	input_mt_init_slots(input, RPI_TS_MAX_SUPPORTED_POINTS,
> +			    INPUT_MT_DIRECT | INPUT_MT_POINTER);

Error handling here please. Also, for touchscreens you do not need to
set INPUT_MT_POINTER, just INPUT_MT_DIRECT.

> +
> +	ret = input_register_polled_device(poll_dev);
> +	if (ret) {
> +		dev_err(dev, "could not register input device, %d\n", ret);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id rpi_ts_match[] = {
> +	{ .compatible = "raspberrypi,firmware-ts", },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, rpi_ts_match);
> +
> +static struct platform_driver rpi_ts_driver = {
> +	.driver = {
> +		.name   = "raspberrypi-ts",
> +		.of_match_table = rpi_ts_match,
> +	},
> +	.probe          = rpi_ts_probe,
> +};
> +module_platform_driver(rpi_ts_driver);
> +
> +MODULE_AUTHOR("Gordon Hollingworth");
> +MODULE_AUTHOR("Nicolas Saenz Julienne <nsaenzjulienne@suse.de>");
> +MODULE_DESCRIPTION("Raspberry Pi 3 firmware based touchscreen driver");
> +MODULE_LICENSE("GPL v2");
> -- 
> 2.19.2
> 

Thanks.

-- 
Dmitry

Re: [PATCH 1/2] input: add official Raspberry Pi's touchscreen driver

[Stefan Wahren]

Hi Nicolas,

> Nicolas Saenz Julienne <nsaenzjulienne@suse.de> hat am 10. Dezember 2018 um 17:30 geschrieben:
> 
> 
> Add's support to Raspberry Pi's 7" Touch device. Instead of using a
> conventional bus all information is copied into a memory mapped area by
> RPi's firmware.
> 
> Based on the driver found in RPi's kernel repository.
> 
> Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
> ---
>  drivers/input/touchscreen/Kconfig          |  12 ++
>  drivers/input/touchscreen/Makefile         |   1 +
>  drivers/input/touchscreen/raspberrypi-ts.c | 223 +++++++++++++++++++++
>  3 files changed, 236 insertions(+)
>  create mode 100644 drivers/input/touchscreen/raspberrypi-ts.c
> 
> diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
> index 2a80675cfd94..a9be434de738 100644
> --- a/drivers/input/touchscreen/Kconfig
> +++ b/drivers/input/touchscreen/Kconfig
> @@ -696,6 +696,18 @@ config TOUCHSCREEN_EDT_FT5X06
>  	  To compile this driver as a module, choose M here: the
>  	  module will be called edt-ft5x06.
>  
> +config TOUCHSCREEN_RASPBERRYPI_TS

I assume TS stands for TOUCHSCREEN, so we can use just TOUCHSCREEN_RASPBERRYPI or TOUCHSCREEN_RASPBERRYPI_FW

> +	tristate "Raspberry Pi's firmware base touch screen support"
> +	depends on RASPBERRYPI_FIRMWARE || COMPILE_TEST
> +	help
> +	  Say Y here if you have the offitial Raspberry Pi 7' scren on your

s/offitial/official/

s/7'/7 inch/

s/scren/screen/

> +	  system.
> +
> +	  If unsure, say N.
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called raspberrypi-ts.
> +
>  config TOUCHSCREEN_MIGOR
>  	tristate "Renesas MIGO-R touchscreen"
>  	depends on (SH_MIGOR || COMPILE_TEST) && I2C
> diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
> index 5911a4190cd2..3eccb1925e89 100644
> --- a/drivers/input/touchscreen/Makefile
> +++ b/drivers/input/touchscreen/Makefile
> @@ -109,3 +109,4 @@ obj-$(CONFIG_TOUCHSCREEN_ZET6223)	+= zet6223.o
>  obj-$(CONFIG_TOUCHSCREEN_ZFORCE)	+= zforce_ts.o
>  obj-$(CONFIG_TOUCHSCREEN_COLIBRI_VF50)	+= colibri-vf50-ts.o
>  obj-$(CONFIG_TOUCHSCREEN_ROHM_BU21023)	+= rohm_bu21023.o
> +obj-$(CONFIG_TOUCHSCREEN_RASPBERRYPI_TS)	+= raspberrypi-ts.o
> diff --git a/drivers/input/touchscreen/raspberrypi-ts.c b/drivers/input/touchscreen/raspberrypi-ts.c
> new file mode 100644
> index 000000000000..edc92018687e
> --- /dev/null
> +++ b/drivers/input/touchscreen/raspberrypi-ts.c
> @@ -0,0 +1,223 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Raspberry Pi 3 firmware based touchscreen driver

AFAIK this driver isn't specific to a Raspberry Pi version, so we can drop the 3

> + *
> + * Copyright (C) 2015, 2017 Raspberry Pi
> + * Copyright (C) 2018 Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
> + */
> +
> +#include <linux/io.h>
> +#include <linux/slab.h>
> +#include <linux/module.h>
> +#include <linux/bitops.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/platform_device.h>

I'm missing linux/of.h and linux/device.h here.

> +#include <linux/input.h>
> +#include <linux/input/mt.h>
> +#include <linux/input-polldev.h>
> +#include <linux/input/touchscreen.h>
> +#include <soc/bcm2835/raspberrypi-firmware.h>
> +
> +#define RPI_TS_DEFAULT_WIDTH	800
> +#define RPI_TS_DEFAULT_HEIGHT	480
> +
> +#define RPI_TS_MAX_SUPPORTED_POINTS	10
> +
> +#define RPI_TS_FTS_TOUCH_DOWN		0
> +#define RPI_TS_FTS_TOUCH_CONTACT	2
> +
> +#define RPI_TS_POLL_INTERVAL		17	/* 60fps */
> +
> +struct rpi_ts {
> +	struct platform_device *pdev;
> +	struct input_polled_dev *poll_dev;
> +	struct touchscreen_properties prop;
> +
> +	void __iomem *fw_regs_va;
> +	dma_addr_t fw_regs_phys;
> +
> +	int known_ids;
> +};
> +
> +struct rpi_ts_regs {
> +	u8 device_mode;
> +	u8 gesture_id;
> +	u8 num_points;
> +	struct rpi_ts_touch {
> +		u8 xh;
> +		u8 xl;
> +		u8 yh;
> +		u8 yl;
> +		u8 pressure; /* Not supported */
> +		u8 area;     /* Not supported */
> +	} point[RPI_TS_MAX_SUPPORTED_POINTS];
> +};
> +
> +/*
> + * We poll the memory based register copy of the touchscreen chip using the
> + * number of points register to know whether the copy has been updated (we
> + * write 99 to the memory copy, the GPU will write between 0 - 10 points)
> + */

I suggest to move this comment below to the memcpy_fromio.

> +static void rpi_ts_poll(struct input_polled_dev *dev)
> +{
> +	struct input_dev *input = dev->input;
> +	struct rpi_ts *ts = dev->private;
> +	struct rpi_ts_regs regs;
> +	int modified_ids = 0;
> +	long released_ids;
> +	int event_type;
> +	int touchid;
> +	int x, y;
> +	int i;
> +
> +	memcpy_fromio(&regs, ts->fw_regs_va, sizeof(regs));
> +	iowrite8(99, ts->fw_regs_va + offsetof(struct rpi_ts_regs, num_points));

I don't have a good name suggestion, but i think the magic 99 should be a define.

> +
> +	if (regs.num_points == 99 ||
> +	    (regs.num_points == 0 && ts->known_ids == 0))
> +	    return;
> +
> +	for (i = 0; i < regs.num_points; i++) {
> +		x = (((int)regs.point[i].xh & 0xf) << 8) + regs.point[i].xl;
> +		y = (((int)regs.point[i].yh & 0xf) << 8) + regs.point[i].yl;
> +		touchid = (regs.point[i].yh >> 4) & 0xf;
> +		event_type = (regs.point[i].xh >> 6) & 0x03;
> +
> +		modified_ids |= BIT(touchid);
> +
> +		if (event_type == RPI_TS_FTS_TOUCH_DOWN ||
> +		    event_type == RPI_TS_FTS_TOUCH_CONTACT) {
> +			input_mt_slot(input, touchid);
> +			input_mt_report_slot_state(input, MT_TOOL_FINGER, 1);
> +			touchscreen_report_pos(input, &ts->prop, x, y, true);
> +		}
> +	}
> +
> +	released_ids = ts->known_ids & ~modified_ids;
> +	for_each_set_bit(i, &released_ids, RPI_TS_MAX_SUPPORTED_POINTS) {
> +		input_mt_slot(input, i);
> +		input_mt_report_slot_state(input, MT_TOOL_FINGER, 0);
> +		modified_ids &= ~(BIT(i));
> +	}
> +	ts->known_ids = modified_ids;
> +
> +	input_mt_sync_frame(input);
> +	input_sync(input);
> +}
> +
> +static void rpi_ts_dma_cleanup(void *data)
> +{
> +	struct rpi_ts *ts = data;
> +	struct device *dev = &ts->pdev->dev;
> +
> +	if(ts->fw_regs_va)
> +		dma_free_coherent(dev, PAGE_SIZE, ts->fw_regs_va,
> +				  ts->fw_regs_phys);
> +}
> +
> +static int rpi_ts_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct device_node *np = dev->of_node;
> +	struct input_polled_dev *poll_dev;
> +	struct device_node *fw_node;
> +	struct rpi_firmware *fw;
> +	struct input_dev *input;
> +	struct rpi_ts *ts;
> +	u32 touchbuf;
> +	int ret;
> +
> +	fw_node = of_get_parent(np);
> +	if (!fw_node) {
> +		dev_err(dev, "Missing firmware node\n");
> +		return -ENOENT;
> +	}
> +
> +	fw = rpi_firmware_get(fw_node);
> +	of_node_put(fw_node);
> +	if (!fw)
> +		return -EPROBE_DEFER;
> +
> +	ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
> +	if (!ts) {
> +		dev_err(dev, "Failed to allocate memory\n");

AFAIK devm_kzalloc already prints an error

> +		return -ENOMEM;
> +	}
> +	ts->pdev = pdev;
> +
> +	ret = devm_add_action_or_reset(dev, rpi_ts_dma_cleanup, ts);
> +	if (ret)
> +		return ret;
> +
> +	ts->fw_regs_va = dma_zalloc_coherent(dev, PAGE_SIZE, &ts->fw_regs_phys,
> +					     GFP_KERNEL);
> +	if (!ts->fw_regs_va) {
> +		dev_err(dev, "failed to dma_alloc_coherent\n");
> +		return -ENOMEM;
> +	}
> +
> +	touchbuf = (u32)ts->fw_regs_phys;
> +	ret = rpi_firmware_property(fw, RPI_FIRMWARE_FRAMEBUFFER_SET_TOUCHBUF,
> +				    &touchbuf, sizeof(touchbuf));
> +
> +	if (ret || touchbuf != 0) {
> +		dev_warn(dev, "Failed to set touchbuf, trying to get err:%x\n",

ret is an integer so %d

> +			 ret);
> +		return ret;
> +	}
> +
> +	poll_dev = devm_input_allocate_polled_device(dev);
> +	if (!poll_dev) {
> +		dev_err(dev, "Failed to allocate input device\n");
> +		return -ENOMEM;
> +	}
> +	ts->poll_dev = poll_dev;
> +	input = poll_dev->input;
> +
> +	input->name = "raspberrypi-ts";
> +	input->id.bustype = BUS_HOST;
> +	poll_dev->poll_interval = RPI_TS_POLL_INTERVAL;
> +	poll_dev->poll = rpi_ts_poll;
> +	poll_dev->private = ts;
> +
> +	__set_bit(EV_SYN, input->evbit);
> +	__set_bit(EV_KEY, input->evbit);
> +	__set_bit(EV_ABS, input->evbit);
> +
> +	input_set_abs_params(input, ABS_MT_POSITION_X, 0,
> +			     RPI_TS_DEFAULT_WIDTH, 0, 0);
> +	input_set_abs_params(input, ABS_MT_POSITION_Y, 0,
> +			     RPI_TS_DEFAULT_HEIGHT, 0, 0);
> +	touchscreen_parse_properties(input, true, &ts->prop);
> +
> +	input_mt_init_slots(input, RPI_TS_MAX_SUPPORTED_POINTS,
> +			    INPUT_MT_DIRECT | INPUT_MT_POINTER);
> +
> +	ret = input_register_polled_device(poll_dev);
> +	if (ret) {
> +		dev_err(dev, "could not register input device, %d\n", ret);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id rpi_ts_match[] = {
> +	{ .compatible = "raspberrypi,firmware-ts", },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, rpi_ts_match);
> +
> +static struct platform_driver rpi_ts_driver = {
> +	.driver = {
> +		.name   = "raspberrypi-ts",
> +		.of_match_table = rpi_ts_match,
> +	},
> +	.probe          = rpi_ts_probe,
> +};
> +module_platform_driver(rpi_ts_driver);
> +
> +MODULE_AUTHOR("Gordon Hollingworth");
> +MODULE_AUTHOR("Nicolas Saenz Julienne <nsaenzjulienne@suse.de>");
> +MODULE_DESCRIPTION("Raspberry Pi 3 firmware based touchscreen driver");

Please also drop the 3 here

> +MODULE_LICENSE("GPL v2");
> -- 
> 2.19.2
>

Re: [PATCH 2/2] Input: raspberrypi-ts - add devicetree binding documentation

[Stefan Wahren]

Hi Nicolas,

please change your subject to something like this:

dt-bindings: input: Add Raspberry Pi Touchscreen

and also change the order of your patches. The binding always comes first.

> Nicolas Saenz Julienne <nsaenzjulienne@suse.de> hat am 10. Dezember 2018 um 17:30 geschrieben:
> 
> 
> Adds device tree documentation for Raspberry Pi's official 7"
> touchscreen.

Maybe you should mention that we need this binding for an overlay.

> 
> Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
> ---
>  .../touchscreen/raspberrypi,firmware-ts.txt   | 26 +++++++++++++++++++
>  1 file changed, 26 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/input/touchscreen/raspberrypi,firmware-ts.txt
> 
> diff --git a/Documentation/devicetree/bindings/input/touchscreen/raspberrypi,firmware-ts.txt b/Documentation/devicetree/bindings/input/touchscreen/raspberrypi,firmware-ts.txt
> new file mode 100644
> index 000000000000..38e22eb222e9
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/input/touchscreen/raspberrypi,firmware-ts.txt
> @@ -0,0 +1,26 @@
> +Raspberry Pi 3 firmware based 7" touchscreen

Please drop the 3 here

> +=====================================
> +
> +Required properties:
> + - compatible: "raspberrypi,firmware-ts"
> +
> +Optional properties:
> + - firmware: Reference to RPi's firmware device node
> + - touchscreen-size-x: See touchscreen.txt
> + - touchscreen-size-y: See touchscreen.txt
> + - touchscreen-inverted-x: See touchscreen.txt
> + - touchscreen-inverted-y: See touchscreen.txt
> + - touchscreen-swapped-x-y: See touchscreen.txt
> +
> +Example:
> +
> +firmware: firmware-rpi {
> +	compatible = "raspberrypi,bcm2835-firmware";
> +	mboxes = <&mailbox>;
> +
> +	ts: touchscreen {
> +		compatible = "raspberrypi,firmware-ts";
> +		touchscreen-size-x = <800>;
> +		touchscreen-size-y = <480>;
> +	};
> +};
> -- 
> 2.19.2
>