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* [RFC PATCH] drivers: Raspbery Pi Sense Hat
@ 2021-04-08  0:03 Joel Savitz
  2021-04-08  9:21 ` Peter Robinson
                   ` (2 more replies)
  0 siblings, 3 replies; 4+ messages in thread
From: Joel Savitz @ 2021-04-08  0:03 UTC (permalink / raw)
  To: linux-rpi-kernel
  Cc: Joel Savitz, Nicolas Saenz Julienne, bcm-kernel-feedback-list,
	linux-arm-kernel, fedora-rpi, serge

From: Joel Savitz <joelsavitz@gmail.com>

This is a forward port of the Rapsberry Pi Sense Hat driver from the
downstream Raspberry Pi kernel tree.

I have slightly consolidated things and done some quick testing of this
driver on Fedora (which comes with the device tree blobs), and I want to
do a bit more testing before submiting the driver for inclusion in
mainline Linux.

I would like to get some feedback from the community on what may need to
be improved, fixed, or changed as early as possible, so this is a request
for comments.

Signed-off-by: Joel Savitz <joelsavitz@gmail.com>
---
 drivers/input/joystick/Kconfig       |   8 +
 drivers/input/joystick/Makefile      |   1 +
 drivers/input/joystick/rpisense-js.c | 147 ++++++++++++++
 drivers/mfd/Kconfig                  |   8 +
 drivers/mfd/Makefile                 |   1 +
 drivers/mfd/rpisense-core.c          | 162 +++++++++++++++
 drivers/video/fbdev/Kconfig          |  13 ++
 drivers/video/fbdev/Makefile         |   1 +
 drivers/video/fbdev/rpisense-fb.c    | 291 +++++++++++++++++++++++++++
 include/linux/mfd/rpisense.h         |  66 ++++++
 10 files changed, 698 insertions(+)
 create mode 100644 drivers/input/joystick/rpisense-js.c
 create mode 100644 drivers/mfd/rpisense-core.c
 create mode 100644 drivers/video/fbdev/rpisense-fb.c
 create mode 100644 include/linux/mfd/rpisense.h

diff --git a/drivers/input/joystick/Kconfig b/drivers/input/joystick/Kconfig
index 5e38899058c1..1c0025c22bf4 100644
--- a/drivers/input/joystick/Kconfig
+++ b/drivers/input/joystick/Kconfig
@@ -389,4 +389,12 @@ config JOYSTICK_N64
 	  Say Y here if you want enable support for the four
 	  built-in controller ports on the Nintendo 64 console.
 
+config JOYSTICK_RPISENSE
+	tristate "Raspberry Pi Sense HAT joystick"
+	depends on GPIOLIB && INPUT
+	select MFD_RPISENSE_CORE
+
+	help
+	  This is the joystick driver for the Raspberry Pi Sense HAT
+
 endif
diff --git a/drivers/input/joystick/Makefile b/drivers/input/joystick/Makefile
index 31d720c9e493..b227e98cd179 100644
--- a/drivers/input/joystick/Makefile
+++ b/drivers/input/joystick/Makefile
@@ -27,6 +27,7 @@ obj-$(CONFIG_JOYSTICK_MAPLE)		+= maplecontrol.o
 obj-$(CONFIG_JOYSTICK_N64)		+= n64joy.o
 obj-$(CONFIG_JOYSTICK_PSXPAD_SPI)	+= psxpad-spi.o
 obj-$(CONFIG_JOYSTICK_PXRC)		+= pxrc.o
+obj-$(CONFIG_JOYSTICK_RPISENSE)         += rpisense-js.o
 obj-$(CONFIG_JOYSTICK_SIDEWINDER)	+= sidewinder.o
 obj-$(CONFIG_JOYSTICK_SPACEBALL)	+= spaceball.o
 obj-$(CONFIG_JOYSTICK_SPACEORB)		+= spaceorb.o
diff --git a/drivers/input/joystick/rpisense-js.c b/drivers/input/joystick/rpisense-js.c
new file mode 100644
index 000000000000..41d4bd1fed46
--- /dev/null
+++ b/drivers/input/joystick/rpisense-js.c
@@ -0,0 +1,147 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Raspberry Pi Sense HAT joystick driver
+ * http://raspberrypi.org
+ *
+ * Copyright (C) 2015 Raspberry Pi
+ *
+ * Author: Serge Schneider
+ * Adapted for mainline Linux by: Joel Savitz
+ */
+
+#include <linux/module.h>
+#include <linux/mfd/rpisense.h>
+
+static struct rpisense *rpisense;
+static unsigned char keymap[5] = {KEY_DOWN, KEY_RIGHT, KEY_UP, KEY_ENTER, KEY_LEFT,};
+
+static void keys_work_fn(struct work_struct *work)
+{
+	int i;
+	static s32 prev_keys;
+	struct rpisense_js *rpisense_js = &rpisense->joystick;
+	s32 keys = rpisense_reg_read(rpisense, RPISENSE_KEYS);
+	s32 changes = keys ^ prev_keys;
+
+	prev_keys = keys;
+	for (i = 0; i < 5; i++) {
+		if (changes & 1) {
+			input_report_key(rpisense_js->keys_dev,
+					 keymap[i], keys & 1);
+		}
+		changes >>= 1;
+		keys >>= 1;
+	}
+	input_sync(rpisense_js->keys_dev);
+}
+
+static irqreturn_t keys_irq_handler(int irq, void *pdev)
+{
+	struct rpisense_js *rpisense_js = &rpisense->joystick;
+
+	schedule_work(&rpisense_js->keys_work_s);
+	return IRQ_HANDLED;
+}
+
+static int rpisense_js_probe(struct platform_device *pdev)
+{
+	int ret;
+	int i;
+	struct rpisense_js *rpisense_js;
+
+	rpisense = rpisense_get_dev();
+	rpisense_js = &rpisense->joystick;
+
+	INIT_WORK(&rpisense_js->keys_work_s, keys_work_fn);
+
+	rpisense_js->keys_dev = input_allocate_device();
+	if (!rpisense_js->keys_dev) {
+		dev_err(&pdev->dev, "Could not allocate input device.\n");
+		return -ENOMEM;
+	}
+
+	rpisense_js->keys_dev->evbit[0] = BIT_MASK(EV_KEY);
+	for (i = 0; i < ARRAY_SIZE(keymap); i++) {
+		set_bit(keymap[i],
+			rpisense_js->keys_dev->keybit);
+	}
+
+	rpisense_js->keys_dev->name = "Raspberry Pi Sense HAT Joystick";
+	rpisense_js->keys_dev->phys = "rpi-sense-joy/input0";
+	rpisense_js->keys_dev->id.bustype = BUS_I2C;
+	rpisense_js->keys_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REP);
+	rpisense_js->keys_dev->keycode = keymap;
+	rpisense_js->keys_dev->keycodesize = sizeof(unsigned char);
+	rpisense_js->keys_dev->keycodemax = ARRAY_SIZE(keymap);
+
+	ret = input_register_device(rpisense_js->keys_dev);
+	if (ret) {
+		dev_err(&pdev->dev, "Could not register input device.\n");
+		goto err_keys_alloc;
+	}
+
+	ret = gpiod_direction_input(rpisense_js->keys_desc);
+	if (ret) {
+		dev_err(&pdev->dev, "Could not set keys-int direction.\n");
+		goto err_keys_reg;
+	}
+
+	rpisense_js->keys_irq = gpiod_to_irq(rpisense_js->keys_desc);
+	if (rpisense_js->keys_irq < 0) {
+		dev_err(&pdev->dev, "Could not determine keys-int IRQ.\n");
+		ret = rpisense_js->keys_irq;
+		goto err_keys_reg;
+	}
+
+	ret = devm_request_irq(&pdev->dev, rpisense_js->keys_irq,
+			       keys_irq_handler, IRQF_TRIGGER_RISING,
+			       "keys", &pdev->dev);
+	if (ret) {
+		dev_err(&pdev->dev, "IRQ request failed.\n");
+		goto err_keys_reg;
+	}
+	return 0;
+err_keys_reg:
+	input_unregister_device(rpisense_js->keys_dev);
+err_keys_alloc:
+	input_free_device(rpisense_js->keys_dev);
+	return ret;
+}
+
+static int rpisense_js_remove(struct platform_device *pdev)
+{
+	struct rpisense_js *rpisense_js = &rpisense->joystick;
+
+	input_unregister_device(rpisense_js->keys_dev);
+	input_free_device(rpisense_js->keys_dev);
+	return 0;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id rpisense_js_id[] = {
+	{ .compatible = "raspberrypi,rpi-sense-js" },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, rpisense_js_id);
+#endif
+
+static struct platform_device_id rpisense_js_device_id[] = {
+	{ .name = "rpi-sense-js" },
+	{ },
+};
+MODULE_DEVICE_TABLE(platform, rpisense_js_device_id);
+
+static struct platform_driver rpisense_js_driver = {
+	.probe = rpisense_js_probe,
+	.remove = rpisense_js_remove,
+	.driver = {
+		.name = "rpi-sense-js",
+		.owner = THIS_MODULE,
+	},
+};
+
+module_platform_driver(rpisense_js_driver);
+
+MODULE_DESCRIPTION("Raspberry Pi Sense HAT joystick driver");
+MODULE_AUTHOR("Serge Schneider <serge@raspberrypi.org>");
+MODULE_LICENSE("GPL");
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index b74efa469e90..8c309e389359 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -11,6 +11,14 @@ config MFD_CORE
 	select IRQ_DOMAIN
 	default n
 
+config MFD_RPISENSE_CORE
+	tristate "Raspberry Pi Sense HAT core functions"
+	depends on I2C
+	select MFD_CORE
+	help
+	  This is the core driver for the Raspberry Pi Sense HAT. This provides
+	  the necessary functions to communicate with the hardware.
+
 config MFD_CS5535
 	tristate "AMD CS5535 and CS5536 southbridge core functions"
 	select MFD_CORE
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 834f5463af28..7140a8fc36ee 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -263,6 +263,7 @@ obj-$(CONFIG_MFD_ROHM_BD71828)	+= rohm-bd71828.o
 obj-$(CONFIG_MFD_ROHM_BD718XX)	+= rohm-bd718x7.o
 obj-$(CONFIG_MFD_STMFX) 	+= stmfx.o
 obj-$(CONFIG_MFD_KHADAS_MCU) 	+= khadas-mcu.o
+obj-$(CONFIG_MFD_RPISENSE_CORE) += rpisense-core.o
 obj-$(CONFIG_MFD_ACER_A500_EC)	+= acer-ec-a500.o
 
 obj-$(CONFIG_SGI_MFD_IOC3)	+= ioc3.o
diff --git a/drivers/mfd/rpisense-core.c b/drivers/mfd/rpisense-core.c
new file mode 100644
index 000000000000..aa2c394c5e67
--- /dev/null
+++ b/drivers/mfd/rpisense-core.c
@@ -0,0 +1,162 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Raspberry Pi Sense HAT core driver
+ * http://raspberrypi.org
+ *
+ * Copyright (C) 2015 Raspberry Pi
+ *
+ * Author: Serge Schneider
+ * Adapted for mainline Linux by: Joel Savitz
+ *
+ *  This driver is based on wm8350 implementation.
+ */
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/i2c.h>
+#include <linux/slab.h>
+
+#include <linux/mfd/rpisense.h>
+
+static struct rpisense *rpisense;
+
+static void rpisense_client_dev_register(struct rpisense *rpisense,
+					 const char *name,
+					 struct platform_device **pdev)
+{
+	int ret;
+
+	*pdev = platform_device_alloc(name, -1);
+	if (*pdev == NULL) {
+		dev_err(rpisense->dev, "Failed to allocate %s\n", name);
+		return;
+	}
+
+	(*pdev)->dev.parent = rpisense->dev;
+	platform_set_drvdata(*pdev, rpisense);
+	ret = platform_device_add(*pdev);
+	if (ret != 0) {
+		dev_err(rpisense->dev, "Failed to register %s: %d\n",
+			name, ret);
+		platform_device_put(*pdev);
+		*pdev = NULL;
+	}
+}
+
+static int rpisense_probe(struct i2c_client *i2c,
+			       const struct i2c_device_id *id)
+{
+	int ret;
+	struct rpisense_js *rpisense_js;
+
+	rpisense = devm_kzalloc(&i2c->dev, sizeof(struct rpisense), GFP_KERNEL);
+	if (rpisense == NULL)
+		return -ENOMEM;
+
+	i2c_set_clientdata(i2c, rpisense);
+	rpisense->dev = &i2c->dev;
+	rpisense->i2c_client = i2c;
+
+	ret = rpisense_reg_read(rpisense, RPISENSE_WAI);
+	if (ret > 0) {
+		if (ret != 's')
+			return -EINVAL;
+	} else {
+		return ret;
+	}
+	ret = rpisense_reg_read(rpisense, RPISENSE_VER);
+	if (ret < 0)
+		return ret;
+
+	dev_info(rpisense->dev,
+		 "Raspberry Pi Sense HAT firmware version %i\n", ret);
+
+	rpisense_js = &rpisense->joystick;
+	rpisense_js->keys_desc = devm_gpiod_get(&i2c->dev,
+						"keys-int", GPIOD_IN);
+	if (IS_ERR(rpisense_js->keys_desc)) {
+		dev_warn(&i2c->dev, "Failed to get keys-int descriptor.\n");
+		rpisense_js->keys_desc = gpio_to_desc(23);
+		if (rpisense_js->keys_desc == NULL) {
+			dev_err(&i2c->dev, "GPIO23 fallback failed.\n");
+			return PTR_ERR(rpisense_js->keys_desc);
+		}
+	}
+	rpisense_client_dev_register(rpisense, "rpi-sense-js",
+				     &(rpisense->joystick.pdev));
+	rpisense_client_dev_register(rpisense, "rpi-sense-fb",
+				     &(rpisense->framebuffer.pdev));
+
+	return 0;
+}
+
+static int rpisense_remove(struct i2c_client *i2c)
+{
+	struct rpisense *rpisense = i2c_get_clientdata(i2c);
+
+	platform_device_unregister(rpisense->joystick.pdev);
+	return 0;
+}
+
+struct rpisense *rpisense_get_dev(void)
+{
+	return rpisense;
+}
+EXPORT_SYMBOL_GPL(rpisense_get_dev);
+
+s32 rpisense_reg_read(struct rpisense *rpisense, int reg)
+{
+	int ret = i2c_smbus_read_byte_data(rpisense->i2c_client, reg);
+
+	if (ret < 0)
+		dev_err(rpisense->dev, "Read from reg %d failed\n", reg);
+	/* Due to the BCM270x I2C clock stretching bug, some values
+	 * may have MSB set. Clear it to avoid incorrect values.
+	 */
+	return ret & 0x7F;
+}
+EXPORT_SYMBOL_GPL(rpisense_reg_read);
+
+int rpisense_block_write(struct rpisense *rpisense, const char *buf, int count)
+{
+	int ret = i2c_master_send(rpisense->i2c_client, buf, count);
+
+	if (ret < 0)
+		dev_err(rpisense->dev, "Block write failed\n");
+	return ret;
+}
+EXPORT_SYMBOL_GPL(rpisense_block_write);
+
+static const struct i2c_device_id rpisense_i2c_id[] = {
+	{ "rpi-sense", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, rpisense_i2c_id);
+
+#ifdef CONFIG_OF
+static const struct of_device_id rpisense_core_id[] = {
+	{ .compatible = "raspberrypi,rpi-sense" },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, rpisense_core_id);
+#endif
+
+
+static struct i2c_driver rpisense_driver = {
+	.driver = {
+		   .name = "rpi-sense",
+		   .owner = THIS_MODULE,
+	},
+	.probe = rpisense_probe,
+	.remove = rpisense_remove,
+	.id_table = rpisense_i2c_id,
+};
+
+module_i2c_driver(rpisense_driver);
+
+MODULE_DESCRIPTION("Raspberry Pi Sense HAT core driver");
+MODULE_AUTHOR("Serge Schneider <serge@raspberrypi.org>");
+MODULE_LICENSE("GPL");
+
diff --git a/drivers/video/fbdev/Kconfig b/drivers/video/fbdev/Kconfig
index 4f02db65dede..2238e36e71e4 100644
--- a/drivers/video/fbdev/Kconfig
+++ b/drivers/video/fbdev/Kconfig
@@ -2236,6 +2236,19 @@ config FB_SM712
 	  called sm712fb. If you want to compile it as a module, say M
 	  here and read <file:Documentation/kbuild/modules.rst>.
 
+config FB_RPISENSE
+        tristate "Raspberry Pi Sense HAT framebuffer"
+        depends on FB
+        select MFD_RPISENSE_CORE
+        select FB_SYS_FOPS
+        select FB_SYS_FILLRECT
+        select FB_SYS_COPYAREA
+        select FB_SYS_IMAGEBLIT
+        select FB_DEFERRED_IO
+
+        help
+          This is the framebuffer driver for the Raspberry Pi Sense HAT
+
 source "drivers/video/fbdev/omap/Kconfig"
 source "drivers/video/fbdev/omap2/Kconfig"
 source "drivers/video/fbdev/mmp/Kconfig"
diff --git a/drivers/video/fbdev/Makefile b/drivers/video/fbdev/Makefile
index 477b9624b703..5b17203b7e43 100644
--- a/drivers/video/fbdev/Makefile
+++ b/drivers/video/fbdev/Makefile
@@ -129,6 +129,7 @@ obj-$(CONFIG_FB_MX3)		  += mx3fb.o
 obj-$(CONFIG_FB_DA8XX)		  += da8xx-fb.o
 obj-$(CONFIG_FB_SSD1307)	  += ssd1307fb.o
 obj-$(CONFIG_FB_SIMPLE)           += simplefb.o
+obj-$(CONFIG_FB_RPISENSE)         += rpisense-fb.o
 
 # the test framebuffer is last
 obj-$(CONFIG_FB_VIRTUAL)          += vfb.o
diff --git a/drivers/video/fbdev/rpisense-fb.c b/drivers/video/fbdev/rpisense-fb.c
new file mode 100644
index 000000000000..a90a5ec51fd7
--- /dev/null
+++ b/drivers/video/fbdev/rpisense-fb.c
@@ -0,0 +1,291 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Raspberry Pi Sense HAT framebuffer driver
+ * http://raspberrypi.org
+ *
+ * Copyright (C) 2015 Raspberry Pi
+ *
+ * Author: Serge Schneider
+ * Adapted for mainline Linux by: Joel Savitz
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/delay.h>
+#include <linux/fb.h>
+#include <linux/init.h>
+
+#include <linux/mfd/rpisense.h>
+
+static bool lowlight;
+module_param(lowlight, bool, 0);
+MODULE_PARM_DESC(lowlight, "Reduce LED matrix brightness to one third");
+
+static struct rpisense *rpisense;
+
+struct rpisense_fb_param {
+	char __iomem *vmem;
+	u8 *vmem_work;
+	u32 vmemsize;
+	u8 *gamma;
+};
+
+static u8 gamma_default[32] = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x01,
+			       0x02, 0x02, 0x03, 0x03, 0x04, 0x05, 0x06, 0x07,
+			       0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0E, 0x0F, 0x11,
+			       0x12, 0x14, 0x15, 0x17, 0x19, 0x1B, 0x1D, 0x1F,};
+
+static u8 gamma_low[32] = {0x00, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
+			   0x01, 0x01, 0x01, 0x01, 0x01, 0x02, 0x02, 0x02,
+			   0x03, 0x03, 0x03, 0x04, 0x04, 0x05, 0x05, 0x06,
+			   0x06, 0x07, 0x07, 0x08, 0x08, 0x09, 0x0A, 0x0A,};
+
+static u8 gamma_user[32];
+
+static u32 pseudo_palette[16];
+
+static struct rpisense_fb_param rpisense_fb_param = {
+	.vmem = NULL,
+	.vmemsize = 128,
+	.gamma = gamma_default,
+};
+
+static struct fb_deferred_io rpisense_fb_defio;
+
+static struct fb_fix_screeninfo rpisense_fb_fix = {
+	.id =		"RPi-Sense FB",
+	.type =		FB_TYPE_PACKED_PIXELS,
+	.visual =	FB_VISUAL_TRUECOLOR,
+	.xpanstep =	0,
+	.ypanstep =	0,
+	.ywrapstep =	0,
+	.accel =	FB_ACCEL_NONE,
+	.line_length =	16,
+};
+
+static struct fb_var_screeninfo rpisense_fb_var = {
+	.xres		= 8,
+	.yres		= 8,
+	.xres_virtual	= 8,
+	.yres_virtual	= 8,
+	.bits_per_pixel = 16,
+	.red		= {11, 5, 0},
+	.green		= {5, 6, 0},
+	.blue		= {0, 5, 0},
+};
+
+static ssize_t rpisense_fb_write(struct fb_info *info,
+				 const char __user *buf, size_t count,
+				 loff_t *ppos)
+{
+	ssize_t res = fb_sys_write(info, buf, count, ppos);
+
+	schedule_delayed_work(&info->deferred_work, rpisense_fb_defio.delay);
+	return res;
+}
+
+static void rpisense_fb_fillrect(struct fb_info *info,
+				 const struct fb_fillrect *rect)
+{
+	sys_fillrect(info, rect);
+	schedule_delayed_work(&info->deferred_work, rpisense_fb_defio.delay);
+}
+
+static void rpisense_fb_copyarea(struct fb_info *info,
+				 const struct fb_copyarea *area)
+{
+	sys_copyarea(info, area);
+	schedule_delayed_work(&info->deferred_work, rpisense_fb_defio.delay);
+}
+
+static void rpisense_fb_imageblit(struct fb_info *info,
+				  const struct fb_image *image)
+{
+	sys_imageblit(info, image);
+	schedule_delayed_work(&info->deferred_work, rpisense_fb_defio.delay);
+}
+
+static void rpisense_fb_deferred_io(struct fb_info *info,
+				struct list_head *pagelist)
+{
+	int i;
+	int j;
+	u8 *vmem_work = rpisense_fb_param.vmem_work;
+	u16 *mem = (u16 *)rpisense_fb_param.vmem;
+	u8 *gamma = rpisense_fb_param.gamma;
+
+	vmem_work[0] = 0;
+	for (j = 0; j < 8; j++) {
+		for (i = 0; i < 8; i++) {
+			vmem_work[(j * 24) + i + 1] =
+				gamma[(mem[(j * 8) + i] >> 11) & 0x1F];
+			vmem_work[(j * 24) + (i + 8) + 1] =
+				gamma[(mem[(j * 8) + i] >> 6) & 0x1F];
+			vmem_work[(j * 24) + (i + 16) + 1] =
+				gamma[(mem[(j * 8) + i]) & 0x1F];
+		}
+	}
+	rpisense_block_write(rpisense, vmem_work, 193);
+}
+
+static struct fb_deferred_io rpisense_fb_defio = {
+	.delay		= HZ/100,
+	.deferred_io	= rpisense_fb_deferred_io,
+};
+
+static int rpisense_fb_ioctl(struct fb_info *info, unsigned int cmd,
+			     unsigned long arg)
+{
+	switch (cmd) {
+	case SENSEFB_FBIOGET_GAMMA:
+		if (copy_to_user((void __user *) arg, rpisense_fb_param.gamma,
+				 sizeof(u8[32])))
+			return -EFAULT;
+		return 0;
+	case SENSEFB_FBIOSET_GAMMA:
+		if (copy_from_user(gamma_user, (void __user *)arg,
+				   sizeof(u8[32])))
+			return -EFAULT;
+		rpisense_fb_param.gamma = gamma_user;
+		schedule_delayed_work(&info->deferred_work,
+				      rpisense_fb_defio.delay);
+		return 0;
+	case SENSEFB_FBIORESET_GAMMA:
+		switch (arg) {
+		case 0:
+			rpisense_fb_param.gamma = gamma_default;
+			break;
+		case 1:
+			rpisense_fb_param.gamma = gamma_low;
+			break;
+		case 2:
+			rpisense_fb_param.gamma = gamma_user;
+			break;
+		default:
+			return -EINVAL;
+		}
+		schedule_delayed_work(&info->deferred_work,
+				      rpisense_fb_defio.delay);
+		break;
+	default:
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static struct fb_ops rpisense_fb_ops = {
+	.owner		= THIS_MODULE,
+	.fb_read	= fb_sys_read,
+	.fb_write	= rpisense_fb_write,
+	.fb_fillrect	= rpisense_fb_fillrect,
+	.fb_copyarea	= rpisense_fb_copyarea,
+	.fb_imageblit	= rpisense_fb_imageblit,
+	.fb_ioctl	= rpisense_fb_ioctl,
+};
+
+static int rpisense_fb_probe(struct platform_device *pdev)
+{
+	struct fb_info *info;
+	int ret = -ENOMEM;
+	struct rpisense_fb *rpisense_fb;
+
+	rpisense = rpisense_get_dev();
+	rpisense_fb = &rpisense->framebuffer;
+
+	rpisense_fb_param.vmem = vzalloc(rpisense_fb_param.vmemsize);
+	if (!rpisense_fb_param.vmem)
+		return ret;
+
+	rpisense_fb_param.vmem_work = devm_kmalloc(&pdev->dev, 193, GFP_KERNEL);
+	if (!rpisense_fb_param.vmem_work)
+		goto err_malloc;
+
+	info = framebuffer_alloc(0, &pdev->dev);
+	if (!info) {
+		dev_err(&pdev->dev, "Could not allocate framebuffer.\n");
+		goto err_malloc;
+	}
+	rpisense_fb->info = info;
+
+	rpisense_fb_fix.smem_start = (unsigned long)rpisense_fb_param.vmem;
+	rpisense_fb_fix.smem_len = rpisense_fb_param.vmemsize;
+
+	info->fbops = &rpisense_fb_ops;
+	info->fix = rpisense_fb_fix;
+	info->var = rpisense_fb_var;
+	info->fbdefio = &rpisense_fb_defio;
+	info->flags = FBINFO_FLAG_DEFAULT | FBINFO_VIRTFB;
+	info->screen_base = rpisense_fb_param.vmem;
+	info->screen_size = rpisense_fb_param.vmemsize;
+	info->pseudo_palette = pseudo_palette;
+
+	if (lowlight)
+		rpisense_fb_param.gamma = gamma_low;
+
+	fb_deferred_io_init(info);
+
+	ret = register_framebuffer(info);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "Could not register framebuffer.\n");
+		goto err_fballoc;
+	}
+
+	fb_info(info, "%s frame buffer device\n", info->fix.id);
+	schedule_delayed_work(&info->deferred_work, rpisense_fb_defio.delay);
+	return 0;
+err_fballoc:
+	framebuffer_release(info);
+err_malloc:
+	vfree(rpisense_fb_param.vmem);
+	return ret;
+}
+
+static int rpisense_fb_remove(struct platform_device *pdev)
+{
+	struct rpisense_fb *rpisense_fb = &rpisense->framebuffer;
+	struct fb_info *info = rpisense_fb->info;
+
+	if (info) {
+		unregister_framebuffer(info);
+		fb_deferred_io_cleanup(info);
+		framebuffer_release(info);
+		vfree(rpisense_fb_param.vmem);
+	}
+
+	return 0;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id rpisense_fb_id[] = {
+	{ .compatible = "raspberrypi,rpi-sense-fb" },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, rpisense_fb_id);
+#endif
+
+static struct platform_device_id rpisense_fb_device_id[] = {
+	{ .name = "rpi-sense-fb" },
+	{ },
+};
+MODULE_DEVICE_TABLE(platform, rpisense_fb_device_id);
+
+static struct platform_driver rpisense_fb_driver = {
+	.probe = rpisense_fb_probe,
+	.remove = rpisense_fb_remove,
+	.driver = {
+		.name = "rpi-sense-fb",
+		.owner = THIS_MODULE,
+	},
+};
+
+module_platform_driver(rpisense_fb_driver);
+
+MODULE_DESCRIPTION("Raspberry Pi Sense HAT framebuffer driver");
+MODULE_AUTHOR("Serge Schneider <serge@raspberrypi.org>");
+MODULE_LICENSE("GPL");
+
diff --git a/include/linux/mfd/rpisense.h b/include/linux/mfd/rpisense.h
new file mode 100644
index 000000000000..0718b6f0eddb
--- /dev/null
+++ b/include/linux/mfd/rpisense.h
@@ -0,0 +1,66 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Raspberry Pi Sense HAT core driver
+ * http://raspberrypi.org
+ *
+ * Copyright (C) 2015 Raspberry Pi
+ *
+ * Author: Serge Schneider
+ * Adapted for mainline Linux by: Joel Savitz
+ */
+
+#ifndef __LINUX_MFD_RPISENSE_CORE_H_
+#define __LINUX_MFD_RPISENSE_CORE_H_
+
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/gpio/consumer.h>
+#include <linux/platform_device.h>
+
+/*
+ * Register values.
+ */
+#define RPISENSE_FB			0x00
+#define RPISENSE_WAI			0xF0
+#define RPISENSE_VER			0xF1
+#define RPISENSE_KEYS			0xF2
+#define RPISENSE_EE_WP			0xF3
+
+#define RPISENSE_ID			's'
+
+#define SENSEFB_FBIO_IOC_MAGIC 0xF1
+
+#define SENSEFB_FBIOGET_GAMMA _IO(SENSEFB_FBIO_IOC_MAGIC, 0)
+#define SENSEFB_FBIOSET_GAMMA _IO(SENSEFB_FBIO_IOC_MAGIC, 1)
+#define SENSEFB_FBIORESET_GAMMA _IO(SENSEFB_FBIO_IOC_MAGIC, 2)
+
+struct rpisense_fb {
+	struct platform_device *pdev;
+	struct fb_info *info;
+};
+
+
+struct rpisense_js {
+	struct platform_device *pdev;
+	struct input_dev *keys_dev;
+	struct gpio_desc *keys_desc;
+	struct work_struct keys_work_s;
+	int keys_irq;
+};
+
+
+struct rpisense {
+	struct device *dev;
+	struct i2c_client *i2c_client;
+
+	/* Client devices */
+	struct rpisense_js joystick;
+	struct rpisense_fb framebuffer;
+};
+
+struct rpisense *rpisense_get_dev(void);
+s32 rpisense_reg_read(struct rpisense *rpisense, int reg);
+int rpisense_reg_write(struct rpisense *rpisense, int reg, u16 val);
+int rpisense_block_write(struct rpisense *rpisense, const char *buf, int count);
+
+#endif
-- 
2.27.0


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^ permalink raw reply related	[flat|nested] 4+ messages in thread

* Re: [RFC PATCH] drivers: Raspbery Pi Sense Hat
  2021-04-08  0:03 [RFC PATCH] drivers: Raspbery Pi Sense Hat Joel Savitz
@ 2021-04-08  9:21 ` Peter Robinson
  2021-04-08 16:16 ` Nicolas Saenz Julienne
  2021-04-08 19:29 ` Stefan Wahren
  2 siblings, 0 replies; 4+ messages in thread
From: Peter Robinson @ 2021-04-08  9:21 UTC (permalink / raw)
  To: Joel Savitz
  Cc: linux-rpi-kernel, fedora-rpi, serge, bcm-kernel-feedback-list,
	Joel Savitz, linux-arm-kernel

 " Hi Joel,

> This is a forward port of the Rapsberry Pi Sense Hat driver from the
> downstream Raspberry Pi kernel tree.

Please copy/reference the original author of the driver that is being
forward ported if it's not you.

> I have slightly consolidated things and done some quick testing of this
> driver on Fedora (which comes with the device tree blobs), and I want to
> do a bit more testing before submiting the driver for inclusion in
> mainline Linux.
>
> I would like to get some feedback from the community on what may need to
> be improved, fixed, or changed as early as possible, so this is a request
> for comments.

Without reviewing the actual drivers I would suggest:
1) split each driver out into a separate patch with a cover letter for
the series
2) Each of the drivers will also need to have their subsystem mailing
lists copied. Something like "./scripts/get_maintainer.pl -f
drivers/input/Kconfig" should give you this information
3) I suspect each of the drivers will also need a DT bindings added to
Documentation/devicetree/bindings/ as a separate patch

Peter

> Signed-off-by: Joel Savitz <joelsavitz@gmail.com>
> ---
>  drivers/input/joystick/Kconfig       |   8 +
>  drivers/input/joystick/Makefile      |   1 +
>  drivers/input/joystick/rpisense-js.c | 147 ++++++++++++++
>  drivers/mfd/Kconfig                  |   8 +
>  drivers/mfd/Makefile                 |   1 +
>  drivers/mfd/rpisense-core.c          | 162 +++++++++++++++
>  drivers/video/fbdev/Kconfig          |  13 ++
>  drivers/video/fbdev/Makefile         |   1 +
>  drivers/video/fbdev/rpisense-fb.c    | 291 +++++++++++++++++++++++++++
>  include/linux/mfd/rpisense.h         |  66 ++++++
>  10 files changed, 698 insertions(+)
>  create mode 100644 drivers/input/joystick/rpisense-js.c
>  create mode 100644 drivers/mfd/rpisense-core.c
>  create mode 100644 drivers/video/fbdev/rpisense-fb.c
>  create mode 100644 include/linux/mfd/rpisense.h
>
> diff --git a/drivers/input/joystick/Kconfig b/drivers/input/joystick/Kconfig
> index 5e38899058c1..1c0025c22bf4 100644
> --- a/drivers/input/joystick/Kconfig
> +++ b/drivers/input/joystick/Kconfig
> @@ -389,4 +389,12 @@ config JOYSTICK_N64
>           Say Y here if you want enable support for the four
>           built-in controller ports on the Nintendo 64 console.
>
> +config JOYSTICK_RPISENSE
> +       tristate "Raspberry Pi Sense HAT joystick"
> +       depends on GPIOLIB && INPUT
> +       select MFD_RPISENSE_CORE
> +
> +       help
> +         This is the joystick driver for the Raspberry Pi Sense HAT
> +
>  endif
> diff --git a/drivers/input/joystick/Makefile b/drivers/input/joystick/Makefile
> index 31d720c9e493..b227e98cd179 100644
> --- a/drivers/input/joystick/Makefile
> +++ b/drivers/input/joystick/Makefile
> @@ -27,6 +27,7 @@ obj-$(CONFIG_JOYSTICK_MAPLE)          += maplecontrol.o
>  obj-$(CONFIG_JOYSTICK_N64)             += n64joy.o
>  obj-$(CONFIG_JOYSTICK_PSXPAD_SPI)      += psxpad-spi.o
>  obj-$(CONFIG_JOYSTICK_PXRC)            += pxrc.o
> +obj-$(CONFIG_JOYSTICK_RPISENSE)         += rpisense-js.o
>  obj-$(CONFIG_JOYSTICK_SIDEWINDER)      += sidewinder.o
>  obj-$(CONFIG_JOYSTICK_SPACEBALL)       += spaceball.o
>  obj-$(CONFIG_JOYSTICK_SPACEORB)                += spaceorb.o
> diff --git a/drivers/input/joystick/rpisense-js.c b/drivers/input/joystick/rpisense-js.c
> new file mode 100644
> index 000000000000..41d4bd1fed46
> --- /dev/null
> +++ b/drivers/input/joystick/rpisense-js.c
> @@ -0,0 +1,147 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Raspberry Pi Sense HAT joystick driver
> + * http://raspberrypi.org
> + *
> + * Copyright (C) 2015 Raspberry Pi
> + *
> + * Author: Serge Schneider
> + * Adapted for mainline Linux by: Joel Savitz
> + */
> +
> +#include <linux/module.h>
> +#include <linux/mfd/rpisense.h>
> +
> +static struct rpisense *rpisense;
> +static unsigned char keymap[5] = {KEY_DOWN, KEY_RIGHT, KEY_UP, KEY_ENTER, KEY_LEFT,};
> +
> +static void keys_work_fn(struct work_struct *work)
> +{
> +       int i;
> +       static s32 prev_keys;
> +       struct rpisense_js *rpisense_js = &rpisense->joystick;
> +       s32 keys = rpisense_reg_read(rpisense, RPISENSE_KEYS);
> +       s32 changes = keys ^ prev_keys;
> +
> +       prev_keys = keys;
> +       for (i = 0; i < 5; i++) {
> +               if (changes & 1) {
> +                       input_report_key(rpisense_js->keys_dev,
> +                                        keymap[i], keys & 1);
> +               }
> +               changes >>= 1;
> +               keys >>= 1;
> +       }
> +       input_sync(rpisense_js->keys_dev);
> +}
> +
> +static irqreturn_t keys_irq_handler(int irq, void *pdev)
> +{
> +       struct rpisense_js *rpisense_js = &rpisense->joystick;
> +
> +       schedule_work(&rpisense_js->keys_work_s);
> +       return IRQ_HANDLED;
> +}
> +
> +static int rpisense_js_probe(struct platform_device *pdev)
> +{
> +       int ret;
> +       int i;
> +       struct rpisense_js *rpisense_js;
> +
> +       rpisense = rpisense_get_dev();
> +       rpisense_js = &rpisense->joystick;
> +
> +       INIT_WORK(&rpisense_js->keys_work_s, keys_work_fn);
> +
> +       rpisense_js->keys_dev = input_allocate_device();
> +       if (!rpisense_js->keys_dev) {
> +               dev_err(&pdev->dev, "Could not allocate input device.\n");
> +               return -ENOMEM;
> +       }
> +
> +       rpisense_js->keys_dev->evbit[0] = BIT_MASK(EV_KEY);
> +       for (i = 0; i < ARRAY_SIZE(keymap); i++) {
> +               set_bit(keymap[i],
> +                       rpisense_js->keys_dev->keybit);
> +       }
> +
> +       rpisense_js->keys_dev->name = "Raspberry Pi Sense HAT Joystick";
> +       rpisense_js->keys_dev->phys = "rpi-sense-joy/input0";
> +       rpisense_js->keys_dev->id.bustype = BUS_I2C;
> +       rpisense_js->keys_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REP);
> +       rpisense_js->keys_dev->keycode = keymap;
> +       rpisense_js->keys_dev->keycodesize = sizeof(unsigned char);
> +       rpisense_js->keys_dev->keycodemax = ARRAY_SIZE(keymap);
> +
> +       ret = input_register_device(rpisense_js->keys_dev);
> +       if (ret) {
> +               dev_err(&pdev->dev, "Could not register input device.\n");
> +               goto err_keys_alloc;
> +       }
> +
> +       ret = gpiod_direction_input(rpisense_js->keys_desc);
> +       if (ret) {
> +               dev_err(&pdev->dev, "Could not set keys-int direction.\n");
> +               goto err_keys_reg;
> +       }
> +
> +       rpisense_js->keys_irq = gpiod_to_irq(rpisense_js->keys_desc);
> +       if (rpisense_js->keys_irq < 0) {
> +               dev_err(&pdev->dev, "Could not determine keys-int IRQ.\n");
> +               ret = rpisense_js->keys_irq;
> +               goto err_keys_reg;
> +       }
> +
> +       ret = devm_request_irq(&pdev->dev, rpisense_js->keys_irq,
> +                              keys_irq_handler, IRQF_TRIGGER_RISING,
> +                              "keys", &pdev->dev);
> +       if (ret) {
> +               dev_err(&pdev->dev, "IRQ request failed.\n");
> +               goto err_keys_reg;
> +       }
> +       return 0;
> +err_keys_reg:
> +       input_unregister_device(rpisense_js->keys_dev);
> +err_keys_alloc:
> +       input_free_device(rpisense_js->keys_dev);
> +       return ret;
> +}
> +
> +static int rpisense_js_remove(struct platform_device *pdev)
> +{
> +       struct rpisense_js *rpisense_js = &rpisense->joystick;
> +
> +       input_unregister_device(rpisense_js->keys_dev);
> +       input_free_device(rpisense_js->keys_dev);
> +       return 0;
> +}
> +
> +#ifdef CONFIG_OF
> +static const struct of_device_id rpisense_js_id[] = {
> +       { .compatible = "raspberrypi,rpi-sense-js" },
> +       { },
> +};
> +MODULE_DEVICE_TABLE(of, rpisense_js_id);
> +#endif
> +
> +static struct platform_device_id rpisense_js_device_id[] = {
> +       { .name = "rpi-sense-js" },
> +       { },
> +};
> +MODULE_DEVICE_TABLE(platform, rpisense_js_device_id);
> +
> +static struct platform_driver rpisense_js_driver = {
> +       .probe = rpisense_js_probe,
> +       .remove = rpisense_js_remove,
> +       .driver = {
> +               .name = "rpi-sense-js",
> +               .owner = THIS_MODULE,
> +       },
> +};
> +
> +module_platform_driver(rpisense_js_driver);
> +
> +MODULE_DESCRIPTION("Raspberry Pi Sense HAT joystick driver");
> +MODULE_AUTHOR("Serge Schneider <serge@raspberrypi.org>");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> index b74efa469e90..8c309e389359 100644
> --- a/drivers/mfd/Kconfig
> +++ b/drivers/mfd/Kconfig
> @@ -11,6 +11,14 @@ config MFD_CORE
>         select IRQ_DOMAIN
>         default n
>
> +config MFD_RPISENSE_CORE
> +       tristate "Raspberry Pi Sense HAT core functions"
> +       depends on I2C
> +       select MFD_CORE
> +       help
> +         This is the core driver for the Raspberry Pi Sense HAT. This provides
> +         the necessary functions to communicate with the hardware.
> +
>  config MFD_CS5535
>         tristate "AMD CS5535 and CS5536 southbridge core functions"
>         select MFD_CORE
> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
> index 834f5463af28..7140a8fc36ee 100644
> --- a/drivers/mfd/Makefile
> +++ b/drivers/mfd/Makefile
> @@ -263,6 +263,7 @@ obj-$(CONFIG_MFD_ROHM_BD71828)      += rohm-bd71828.o
>  obj-$(CONFIG_MFD_ROHM_BD718XX) += rohm-bd718x7.o
>  obj-$(CONFIG_MFD_STMFX)        += stmfx.o
>  obj-$(CONFIG_MFD_KHADAS_MCU)   += khadas-mcu.o
> +obj-$(CONFIG_MFD_RPISENSE_CORE) += rpisense-core.o
>  obj-$(CONFIG_MFD_ACER_A500_EC) += acer-ec-a500.o
>
>  obj-$(CONFIG_SGI_MFD_IOC3)     += ioc3.o
> diff --git a/drivers/mfd/rpisense-core.c b/drivers/mfd/rpisense-core.c
> new file mode 100644
> index 000000000000..aa2c394c5e67
> --- /dev/null
> +++ b/drivers/mfd/rpisense-core.c
> @@ -0,0 +1,162 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Raspberry Pi Sense HAT core driver
> + * http://raspberrypi.org
> + *
> + * Copyright (C) 2015 Raspberry Pi
> + *
> + * Author: Serge Schneider
> + * Adapted for mainline Linux by: Joel Savitz
> + *
> + *  This driver is based on wm8350 implementation.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/moduleparam.h>
> +#include <linux/err.h>
> +#include <linux/init.h>
> +#include <linux/i2c.h>
> +#include <linux/slab.h>
> +
> +#include <linux/mfd/rpisense.h>
> +
> +static struct rpisense *rpisense;
> +
> +static void rpisense_client_dev_register(struct rpisense *rpisense,
> +                                        const char *name,
> +                                        struct platform_device **pdev)
> +{
> +       int ret;
> +
> +       *pdev = platform_device_alloc(name, -1);
> +       if (*pdev == NULL) {
> +               dev_err(rpisense->dev, "Failed to allocate %s\n", name);
> +               return;
> +       }
> +
> +       (*pdev)->dev.parent = rpisense->dev;
> +       platform_set_drvdata(*pdev, rpisense);
> +       ret = platform_device_add(*pdev);
> +       if (ret != 0) {
> +               dev_err(rpisense->dev, "Failed to register %s: %d\n",
> +                       name, ret);
> +               platform_device_put(*pdev);
> +               *pdev = NULL;
> +       }
> +}
> +
> +static int rpisense_probe(struct i2c_client *i2c,
> +                              const struct i2c_device_id *id)
> +{
> +       int ret;
> +       struct rpisense_js *rpisense_js;
> +
> +       rpisense = devm_kzalloc(&i2c->dev, sizeof(struct rpisense), GFP_KERNEL);
> +       if (rpisense == NULL)
> +               return -ENOMEM;
> +
> +       i2c_set_clientdata(i2c, rpisense);
> +       rpisense->dev = &i2c->dev;
> +       rpisense->i2c_client = i2c;
> +
> +       ret = rpisense_reg_read(rpisense, RPISENSE_WAI);
> +       if (ret > 0) {
> +               if (ret != 's')
> +                       return -EINVAL;
> +       } else {
> +               return ret;
> +       }
> +       ret = rpisense_reg_read(rpisense, RPISENSE_VER);
> +       if (ret < 0)
> +               return ret;
> +
> +       dev_info(rpisense->dev,
> +                "Raspberry Pi Sense HAT firmware version %i\n", ret);
> +
> +       rpisense_js = &rpisense->joystick;
> +       rpisense_js->keys_desc = devm_gpiod_get(&i2c->dev,
> +                                               "keys-int", GPIOD_IN);
> +       if (IS_ERR(rpisense_js->keys_desc)) {
> +               dev_warn(&i2c->dev, "Failed to get keys-int descriptor.\n");
> +               rpisense_js->keys_desc = gpio_to_desc(23);
> +               if (rpisense_js->keys_desc == NULL) {
> +                       dev_err(&i2c->dev, "GPIO23 fallback failed.\n");
> +                       return PTR_ERR(rpisense_js->keys_desc);
> +               }
> +       }
> +       rpisense_client_dev_register(rpisense, "rpi-sense-js",
> +                                    &(rpisense->joystick.pdev));
> +       rpisense_client_dev_register(rpisense, "rpi-sense-fb",
> +                                    &(rpisense->framebuffer.pdev));
> +
> +       return 0;
> +}
> +
> +static int rpisense_remove(struct i2c_client *i2c)
> +{
> +       struct rpisense *rpisense = i2c_get_clientdata(i2c);
> +
> +       platform_device_unregister(rpisense->joystick.pdev);
> +       return 0;
> +}
> +
> +struct rpisense *rpisense_get_dev(void)
> +{
> +       return rpisense;
> +}
> +EXPORT_SYMBOL_GPL(rpisense_get_dev);
> +
> +s32 rpisense_reg_read(struct rpisense *rpisense, int reg)
> +{
> +       int ret = i2c_smbus_read_byte_data(rpisense->i2c_client, reg);
> +
> +       if (ret < 0)
> +               dev_err(rpisense->dev, "Read from reg %d failed\n", reg);
> +       /* Due to the BCM270x I2C clock stretching bug, some values
> +        * may have MSB set. Clear it to avoid incorrect values.
> +        */
> +       return ret & 0x7F;
> +}
> +EXPORT_SYMBOL_GPL(rpisense_reg_read);
> +
> +int rpisense_block_write(struct rpisense *rpisense, const char *buf, int count)
> +{
> +       int ret = i2c_master_send(rpisense->i2c_client, buf, count);
> +
> +       if (ret < 0)
> +               dev_err(rpisense->dev, "Block write failed\n");
> +       return ret;
> +}
> +EXPORT_SYMBOL_GPL(rpisense_block_write);
> +
> +static const struct i2c_device_id rpisense_i2c_id[] = {
> +       { "rpi-sense", 0 },
> +       { }
> +};
> +MODULE_DEVICE_TABLE(i2c, rpisense_i2c_id);
> +
> +#ifdef CONFIG_OF
> +static const struct of_device_id rpisense_core_id[] = {
> +       { .compatible = "raspberrypi,rpi-sense" },
> +       { },
> +};
> +MODULE_DEVICE_TABLE(of, rpisense_core_id);
> +#endif
> +
> +
> +static struct i2c_driver rpisense_driver = {
> +       .driver = {
> +                  .name = "rpi-sense",
> +                  .owner = THIS_MODULE,
> +       },
> +       .probe = rpisense_probe,
> +       .remove = rpisense_remove,
> +       .id_table = rpisense_i2c_id,
> +};
> +
> +module_i2c_driver(rpisense_driver);
> +
> +MODULE_DESCRIPTION("Raspberry Pi Sense HAT core driver");
> +MODULE_AUTHOR("Serge Schneider <serge@raspberrypi.org>");
> +MODULE_LICENSE("GPL");
> +
> diff --git a/drivers/video/fbdev/Kconfig b/drivers/video/fbdev/Kconfig
> index 4f02db65dede..2238e36e71e4 100644
> --- a/drivers/video/fbdev/Kconfig
> +++ b/drivers/video/fbdev/Kconfig
> @@ -2236,6 +2236,19 @@ config FB_SM712
>           called sm712fb. If you want to compile it as a module, say M
>           here and read <file:Documentation/kbuild/modules.rst>.
>
> +config FB_RPISENSE
> +        tristate "Raspberry Pi Sense HAT framebuffer"
> +        depends on FB
> +        select MFD_RPISENSE_CORE
> +        select FB_SYS_FOPS
> +        select FB_SYS_FILLRECT
> +        select FB_SYS_COPYAREA
> +        select FB_SYS_IMAGEBLIT
> +        select FB_DEFERRED_IO
> +
> +        help
> +          This is the framebuffer driver for the Raspberry Pi Sense HAT
> +
>  source "drivers/video/fbdev/omap/Kconfig"
>  source "drivers/video/fbdev/omap2/Kconfig"
>  source "drivers/video/fbdev/mmp/Kconfig"
> diff --git a/drivers/video/fbdev/Makefile b/drivers/video/fbdev/Makefile
> index 477b9624b703..5b17203b7e43 100644
> --- a/drivers/video/fbdev/Makefile
> +++ b/drivers/video/fbdev/Makefile
> @@ -129,6 +129,7 @@ obj-$(CONFIG_FB_MX3)                  += mx3fb.o
>  obj-$(CONFIG_FB_DA8XX)           += da8xx-fb.o
>  obj-$(CONFIG_FB_SSD1307)         += ssd1307fb.o
>  obj-$(CONFIG_FB_SIMPLE)           += simplefb.o
> +obj-$(CONFIG_FB_RPISENSE)         += rpisense-fb.o
>
>  # the test framebuffer is last
>  obj-$(CONFIG_FB_VIRTUAL)          += vfb.o
> diff --git a/drivers/video/fbdev/rpisense-fb.c b/drivers/video/fbdev/rpisense-fb.c
> new file mode 100644
> index 000000000000..a90a5ec51fd7
> --- /dev/null
> +++ b/drivers/video/fbdev/rpisense-fb.c
> @@ -0,0 +1,291 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Raspberry Pi Sense HAT framebuffer driver
> + * http://raspberrypi.org
> + *
> + * Copyright (C) 2015 Raspberry Pi
> + *
> + * Author: Serge Schneider
> + * Adapted for mainline Linux by: Joel Savitz
> + */
> +
> +#include <linux/module.h>
> +#include <linux/kernel.h>
> +#include <linux/errno.h>
> +#include <linux/string.h>
> +#include <linux/mm.h>
> +#include <linux/slab.h>
> +#include <linux/uaccess.h>
> +#include <linux/delay.h>
> +#include <linux/fb.h>
> +#include <linux/init.h>
> +
> +#include <linux/mfd/rpisense.h>
> +
> +static bool lowlight;
> +module_param(lowlight, bool, 0);
> +MODULE_PARM_DESC(lowlight, "Reduce LED matrix brightness to one third");
> +
> +static struct rpisense *rpisense;
> +
> +struct rpisense_fb_param {
> +       char __iomem *vmem;
> +       u8 *vmem_work;
> +       u32 vmemsize;
> +       u8 *gamma;
> +};
> +
> +static u8 gamma_default[32] = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x01,
> +                              0x02, 0x02, 0x03, 0x03, 0x04, 0x05, 0x06, 0x07,
> +                              0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0E, 0x0F, 0x11,
> +                              0x12, 0x14, 0x15, 0x17, 0x19, 0x1B, 0x1D, 0x1F,};
> +
> +static u8 gamma_low[32] = {0x00, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
> +                          0x01, 0x01, 0x01, 0x01, 0x01, 0x02, 0x02, 0x02,
> +                          0x03, 0x03, 0x03, 0x04, 0x04, 0x05, 0x05, 0x06,
> +                          0x06, 0x07, 0x07, 0x08, 0x08, 0x09, 0x0A, 0x0A,};
> +
> +static u8 gamma_user[32];
> +
> +static u32 pseudo_palette[16];
> +
> +static struct rpisense_fb_param rpisense_fb_param = {
> +       .vmem = NULL,
> +       .vmemsize = 128,
> +       .gamma = gamma_default,
> +};
> +
> +static struct fb_deferred_io rpisense_fb_defio;
> +
> +static struct fb_fix_screeninfo rpisense_fb_fix = {
> +       .id =           "RPi-Sense FB",
> +       .type =         FB_TYPE_PACKED_PIXELS,
> +       .visual =       FB_VISUAL_TRUECOLOR,
> +       .xpanstep =     0,
> +       .ypanstep =     0,
> +       .ywrapstep =    0,
> +       .accel =        FB_ACCEL_NONE,
> +       .line_length =  16,
> +};
> +
> +static struct fb_var_screeninfo rpisense_fb_var = {
> +       .xres           = 8,
> +       .yres           = 8,
> +       .xres_virtual   = 8,
> +       .yres_virtual   = 8,
> +       .bits_per_pixel = 16,
> +       .red            = {11, 5, 0},
> +       .green          = {5, 6, 0},
> +       .blue           = {0, 5, 0},
> +};
> +
> +static ssize_t rpisense_fb_write(struct fb_info *info,
> +                                const char __user *buf, size_t count,
> +                                loff_t *ppos)
> +{
> +       ssize_t res = fb_sys_write(info, buf, count, ppos);
> +
> +       schedule_delayed_work(&info->deferred_work, rpisense_fb_defio.delay);
> +       return res;
> +}
> +
> +static void rpisense_fb_fillrect(struct fb_info *info,
> +                                const struct fb_fillrect *rect)
> +{
> +       sys_fillrect(info, rect);
> +       schedule_delayed_work(&info->deferred_work, rpisense_fb_defio.delay);
> +}
> +
> +static void rpisense_fb_copyarea(struct fb_info *info,
> +                                const struct fb_copyarea *area)
> +{
> +       sys_copyarea(info, area);
> +       schedule_delayed_work(&info->deferred_work, rpisense_fb_defio.delay);
> +}
> +
> +static void rpisense_fb_imageblit(struct fb_info *info,
> +                                 const struct fb_image *image)
> +{
> +       sys_imageblit(info, image);
> +       schedule_delayed_work(&info->deferred_work, rpisense_fb_defio.delay);
> +}
> +
> +static void rpisense_fb_deferred_io(struct fb_info *info,
> +                               struct list_head *pagelist)
> +{
> +       int i;
> +       int j;
> +       u8 *vmem_work = rpisense_fb_param.vmem_work;
> +       u16 *mem = (u16 *)rpisense_fb_param.vmem;
> +       u8 *gamma = rpisense_fb_param.gamma;
> +
> +       vmem_work[0] = 0;
> +       for (j = 0; j < 8; j++) {
> +               for (i = 0; i < 8; i++) {
> +                       vmem_work[(j * 24) + i + 1] =
> +                               gamma[(mem[(j * 8) + i] >> 11) & 0x1F];
> +                       vmem_work[(j * 24) + (i + 8) + 1] =
> +                               gamma[(mem[(j * 8) + i] >> 6) & 0x1F];
> +                       vmem_work[(j * 24) + (i + 16) + 1] =
> +                               gamma[(mem[(j * 8) + i]) & 0x1F];
> +               }
> +       }
> +       rpisense_block_write(rpisense, vmem_work, 193);
> +}
> +
> +static struct fb_deferred_io rpisense_fb_defio = {
> +       .delay          = HZ/100,
> +       .deferred_io    = rpisense_fb_deferred_io,
> +};
> +
> +static int rpisense_fb_ioctl(struct fb_info *info, unsigned int cmd,
> +                            unsigned long arg)
> +{
> +       switch (cmd) {
> +       case SENSEFB_FBIOGET_GAMMA:
> +               if (copy_to_user((void __user *) arg, rpisense_fb_param.gamma,
> +                                sizeof(u8[32])))
> +                       return -EFAULT;
> +               return 0;
> +       case SENSEFB_FBIOSET_GAMMA:
> +               if (copy_from_user(gamma_user, (void __user *)arg,
> +                                  sizeof(u8[32])))
> +                       return -EFAULT;
> +               rpisense_fb_param.gamma = gamma_user;
> +               schedule_delayed_work(&info->deferred_work,
> +                                     rpisense_fb_defio.delay);
> +               return 0;
> +       case SENSEFB_FBIORESET_GAMMA:
> +               switch (arg) {
> +               case 0:
> +                       rpisense_fb_param.gamma = gamma_default;
> +                       break;
> +               case 1:
> +                       rpisense_fb_param.gamma = gamma_low;
> +                       break;
> +               case 2:
> +                       rpisense_fb_param.gamma = gamma_user;
> +                       break;
> +               default:
> +                       return -EINVAL;
> +               }
> +               schedule_delayed_work(&info->deferred_work,
> +                                     rpisense_fb_defio.delay);
> +               break;
> +       default:
> +               return -EINVAL;
> +       }
> +       return 0;
> +}
> +
> +static struct fb_ops rpisense_fb_ops = {
> +       .owner          = THIS_MODULE,
> +       .fb_read        = fb_sys_read,
> +       .fb_write       = rpisense_fb_write,
> +       .fb_fillrect    = rpisense_fb_fillrect,
> +       .fb_copyarea    = rpisense_fb_copyarea,
> +       .fb_imageblit   = rpisense_fb_imageblit,
> +       .fb_ioctl       = rpisense_fb_ioctl,
> +};
> +
> +static int rpisense_fb_probe(struct platform_device *pdev)
> +{
> +       struct fb_info *info;
> +       int ret = -ENOMEM;
> +       struct rpisense_fb *rpisense_fb;
> +
> +       rpisense = rpisense_get_dev();
> +       rpisense_fb = &rpisense->framebuffer;
> +
> +       rpisense_fb_param.vmem = vzalloc(rpisense_fb_param.vmemsize);
> +       if (!rpisense_fb_param.vmem)
> +               return ret;
> +
> +       rpisense_fb_param.vmem_work = devm_kmalloc(&pdev->dev, 193, GFP_KERNEL);
> +       if (!rpisense_fb_param.vmem_work)
> +               goto err_malloc;
> +
> +       info = framebuffer_alloc(0, &pdev->dev);
> +       if (!info) {
> +               dev_err(&pdev->dev, "Could not allocate framebuffer.\n");
> +               goto err_malloc;
> +       }
> +       rpisense_fb->info = info;
> +
> +       rpisense_fb_fix.smem_start = (unsigned long)rpisense_fb_param.vmem;
> +       rpisense_fb_fix.smem_len = rpisense_fb_param.vmemsize;
> +
> +       info->fbops = &rpisense_fb_ops;
> +       info->fix = rpisense_fb_fix;
> +       info->var = rpisense_fb_var;
> +       info->fbdefio = &rpisense_fb_defio;
> +       info->flags = FBINFO_FLAG_DEFAULT | FBINFO_VIRTFB;
> +       info->screen_base = rpisense_fb_param.vmem;
> +       info->screen_size = rpisense_fb_param.vmemsize;
> +       info->pseudo_palette = pseudo_palette;
> +
> +       if (lowlight)
> +               rpisense_fb_param.gamma = gamma_low;
> +
> +       fb_deferred_io_init(info);
> +
> +       ret = register_framebuffer(info);
> +       if (ret < 0) {
> +               dev_err(&pdev->dev, "Could not register framebuffer.\n");
> +               goto err_fballoc;
> +       }
> +
> +       fb_info(info, "%s frame buffer device\n", info->fix.id);
> +       schedule_delayed_work(&info->deferred_work, rpisense_fb_defio.delay);
> +       return 0;
> +err_fballoc:
> +       framebuffer_release(info);
> +err_malloc:
> +       vfree(rpisense_fb_param.vmem);
> +       return ret;
> +}
> +
> +static int rpisense_fb_remove(struct platform_device *pdev)
> +{
> +       struct rpisense_fb *rpisense_fb = &rpisense->framebuffer;
> +       struct fb_info *info = rpisense_fb->info;
> +
> +       if (info) {
> +               unregister_framebuffer(info);
> +               fb_deferred_io_cleanup(info);
> +               framebuffer_release(info);
> +               vfree(rpisense_fb_param.vmem);
> +       }
> +
> +       return 0;
> +}
> +
> +#ifdef CONFIG_OF
> +static const struct of_device_id rpisense_fb_id[] = {
> +       { .compatible = "raspberrypi,rpi-sense-fb" },
> +       { },
> +};
> +MODULE_DEVICE_TABLE(of, rpisense_fb_id);
> +#endif
> +
> +static struct platform_device_id rpisense_fb_device_id[] = {
> +       { .name = "rpi-sense-fb" },
> +       { },
> +};
> +MODULE_DEVICE_TABLE(platform, rpisense_fb_device_id);
> +
> +static struct platform_driver rpisense_fb_driver = {
> +       .probe = rpisense_fb_probe,
> +       .remove = rpisense_fb_remove,
> +       .driver = {
> +               .name = "rpi-sense-fb",
> +               .owner = THIS_MODULE,
> +       },
> +};
> +
> +module_platform_driver(rpisense_fb_driver);
> +
> +MODULE_DESCRIPTION("Raspberry Pi Sense HAT framebuffer driver");
> +MODULE_AUTHOR("Serge Schneider <serge@raspberrypi.org>");
> +MODULE_LICENSE("GPL");
> +
> diff --git a/include/linux/mfd/rpisense.h b/include/linux/mfd/rpisense.h
> new file mode 100644
> index 000000000000..0718b6f0eddb
> --- /dev/null
> +++ b/include/linux/mfd/rpisense.h
> @@ -0,0 +1,66 @@
> +/* SPDX-License-Identifier: GPL-2.0-or-later */
> +/*
> + * Raspberry Pi Sense HAT core driver
> + * http://raspberrypi.org
> + *
> + * Copyright (C) 2015 Raspberry Pi
> + *
> + * Author: Serge Schneider
> + * Adapted for mainline Linux by: Joel Savitz
> + */
> +
> +#ifndef __LINUX_MFD_RPISENSE_CORE_H_
> +#define __LINUX_MFD_RPISENSE_CORE_H_
> +
> +#include <linux/input.h>
> +#include <linux/interrupt.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/platform_device.h>
> +
> +/*
> + * Register values.
> + */
> +#define RPISENSE_FB                    0x00
> +#define RPISENSE_WAI                   0xF0
> +#define RPISENSE_VER                   0xF1
> +#define RPISENSE_KEYS                  0xF2
> +#define RPISENSE_EE_WP                 0xF3
> +
> +#define RPISENSE_ID                    's'
> +
> +#define SENSEFB_FBIO_IOC_MAGIC 0xF1
> +
> +#define SENSEFB_FBIOGET_GAMMA _IO(SENSEFB_FBIO_IOC_MAGIC, 0)
> +#define SENSEFB_FBIOSET_GAMMA _IO(SENSEFB_FBIO_IOC_MAGIC, 1)
> +#define SENSEFB_FBIORESET_GAMMA _IO(SENSEFB_FBIO_IOC_MAGIC, 2)
> +
> +struct rpisense_fb {
> +       struct platform_device *pdev;
> +       struct fb_info *info;
> +};
> +
> +
> +struct rpisense_js {
> +       struct platform_device *pdev;
> +       struct input_dev *keys_dev;
> +       struct gpio_desc *keys_desc;
> +       struct work_struct keys_work_s;
> +       int keys_irq;
> +};
> +
> +
> +struct rpisense {
> +       struct device *dev;
> +       struct i2c_client *i2c_client;
> +
> +       /* Client devices */
> +       struct rpisense_js joystick;
> +       struct rpisense_fb framebuffer;
> +};
> +
> +struct rpisense *rpisense_get_dev(void);
> +s32 rpisense_reg_read(struct rpisense *rpisense, int reg);
> +int rpisense_reg_write(struct rpisense *rpisense, int reg, u16 val);
> +int rpisense_block_write(struct rpisense *rpisense, const char *buf, int count);
> +
> +#endif
> --
> 2.27.0
>
>
> _______________________________________________
> linux-rpi-kernel mailing list
> linux-rpi-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-rpi-kernel

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^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [RFC PATCH] drivers: Raspbery Pi Sense Hat
  2021-04-08  0:03 [RFC PATCH] drivers: Raspbery Pi Sense Hat Joel Savitz
  2021-04-08  9:21 ` Peter Robinson
@ 2021-04-08 16:16 ` Nicolas Saenz Julienne
  2021-04-08 19:29 ` Stefan Wahren
  2 siblings, 0 replies; 4+ messages in thread
From: Nicolas Saenz Julienne @ 2021-04-08 16:16 UTC (permalink / raw)
  To: Joel Savitz, linux-rpi-kernel
  Cc: Joel Savitz, bcm-kernel-feedback-list, linux-arm-kernel,
	fedora-rpi, serge


[-- Attachment #1.1: Type: text/plain, Size: 1495 bytes --]

Hi Joel, thanks for having a look at this.

On Wed, 2021-04-07 at 20:03 -0400, Joel Savitz wrote:
> From: Joel Savitz <joelsavitz@gmail.com>
> 
> This is a forward port of the Rapsberry Pi Sense Hat driver from the
> downstream Raspberry Pi kernel tree.
> 
> I have slightly consolidated things and done some quick testing of this
> driver on Fedora (which comes with the device tree blobs), and I want to
> do a bit more testing before submiting the driver for inclusion in
> mainline Linux.
> 
> I would like to get some feedback from the community on what may need to
> be improved, fixed, or changed as early as possible, so this is a request
> for comments.
> 
> Signed-off-by: Joel Savitz <joelsavitz@gmail.com>
> ---

Some random comments:

 - Can you share more info on the HW, is this a uC on the other side? etc...
 - A driver that depends on DT should have bindings.
 - Please have a look at a modern MFD device handles things. New APIs appeared.
   See for example the 'atc260x' driver available in linux-next.
 - Try to use regmap so as not having to export functions across modules.
 - No need to explicitly schedule the interrupt in the joystick driver. New IRQ
   APIs can handle that. See devm_request_threaded_irq().
 - I don't think adding new FB drivers is possible, the whole subsystem is in
   the process of being deprecated. I believe there is an equivalent framework
   in DRM to cater for these simple FB devices.

Regards,
Nicolas


[-- Attachment #1.2: This is a digitally signed message part --]
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^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [RFC PATCH] drivers: Raspbery Pi Sense Hat
  2021-04-08  0:03 [RFC PATCH] drivers: Raspbery Pi Sense Hat Joel Savitz
  2021-04-08  9:21 ` Peter Robinson
  2021-04-08 16:16 ` Nicolas Saenz Julienne
@ 2021-04-08 19:29 ` Stefan Wahren
  2 siblings, 0 replies; 4+ messages in thread
From: Stefan Wahren @ 2021-04-08 19:29 UTC (permalink / raw)
  To: Joel Savitz, linux-rpi-kernel
  Cc: Joel Savitz, Nicolas Saenz Julienne, bcm-kernel-feedback-list,
	linux-arm-kernel, fedora-rpi, serge

Hi Joel,

Am 08.04.21 um 02:03 schrieb Joel Savitz:
> From: Joel Savitz <joelsavitz@gmail.com>
>
> This is a forward port of the Rapsberry Pi Sense Hat driver from the
> downstream Raspberry Pi kernel tree.
>
> I have slightly consolidated things and done some quick testing of this
> driver on Fedora (which comes with the device tree blobs), and I want to
> do a bit more testing before submiting the driver for inclusion in
> mainline Linux.

at first some general comments:

- keep in mind that the drivers shouldn't make any assumption of the
target platform
- always run scripts/checkpatch.pl before submission

>
> I would like to get some feedback from the community on what may need to
> be improved, fixed, or changed as early as possible, so this is a request
> for comments.
>
> Signed-off-by: Joel Savitz <joelsavitz@gmail.com>
> ---
>  drivers/input/joystick/Kconfig       |   8 +
>  drivers/input/joystick/Makefile      |   1 +
>  drivers/input/joystick/rpisense-js.c | 147 ++++++++++++++
>  drivers/mfd/Kconfig                  |   8 +
>  drivers/mfd/Makefile                 |   1 +
>  drivers/mfd/rpisense-core.c          | 162 +++++++++++++++
>  drivers/video/fbdev/Kconfig          |  13 ++
>  drivers/video/fbdev/Makefile         |   1 +
>  drivers/video/fbdev/rpisense-fb.c    | 291 +++++++++++++++++++++++++++
>  include/linux/mfd/rpisense.h         |  66 ++++++
>  10 files changed, 698 insertions(+)
>  create mode 100644 drivers/input/joystick/rpisense-js.c
>  create mode 100644 drivers/mfd/rpisense-core.c
>  create mode 100644 drivers/video/fbdev/rpisense-fb.c
>  create mode 100644 include/linux/mfd/rpisense.h
>
> diff --git a/drivers/input/joystick/Kconfig b/drivers/input/joystick/Kconfig
> index 5e38899058c1..1c0025c22bf4 100644
> --- a/drivers/input/joystick/Kconfig
> +++ b/drivers/input/joystick/Kconfig
> @@ -389,4 +389,12 @@ config JOYSTICK_N64
>  	  Say Y here if you want enable support for the four
>  	  built-in controller ports on the Nintendo 64 console.
>  
> +config JOYSTICK_RPISENSE
> +	tristate "Raspberry Pi Sense HAT joystick"
> +	depends on GPIOLIB && INPUT
> +	select MFD_RPISENSE_CORE
> +
> +	help
> +	  This is the joystick driver for the Raspberry Pi Sense HAT
> +
>  endif
> diff --git a/drivers/input/joystick/Makefile b/drivers/input/joystick/Makefile
> index 31d720c9e493..b227e98cd179 100644
> --- a/drivers/input/joystick/Makefile
> +++ b/drivers/input/joystick/Makefile
> @@ -27,6 +27,7 @@ obj-$(CONFIG_JOYSTICK_MAPLE)		+= maplecontrol.o
>  obj-$(CONFIG_JOYSTICK_N64)		+= n64joy.o
>  obj-$(CONFIG_JOYSTICK_PSXPAD_SPI)	+= psxpad-spi.o
>  obj-$(CONFIG_JOYSTICK_PXRC)		+= pxrc.o
> +obj-$(CONFIG_JOYSTICK_RPISENSE)         += rpisense-js.o
>  obj-$(CONFIG_JOYSTICK_SIDEWINDER)	+= sidewinder.o
>  obj-$(CONFIG_JOYSTICK_SPACEBALL)	+= spaceball.o
>  obj-$(CONFIG_JOYSTICK_SPACEORB)		+= spaceorb.o
> diff --git a/drivers/input/joystick/rpisense-js.c b/drivers/input/joystick/rpisense-js.c
> new file mode 100644
> index 000000000000..41d4bd1fed46
> --- /dev/null
> +++ b/drivers/input/joystick/rpisense-js.c
> @@ -0,0 +1,147 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Raspberry Pi Sense HAT joystick driver
> + * http://raspberrypi.org
> + *
> + * Copyright (C) 2015 Raspberry Pi
> + *
> + * Author: Serge Schneider
> + * Adapted for mainline Linux by: Joel Savitz
> + */
> +
> +#include <linux/module.h>
> +#include <linux/mfd/rpisense.h>
> +
> +static struct rpisense *rpisense;
please try to avoid such limitation. It's preferred to allow multiple
instances of input drivers.
> +static unsigned char keymap[5] = {KEY_DOWN, KEY_RIGHT, KEY_UP, KEY_ENTER, KEY_LEFT,};
please try to avoid magic numbers
> +
> +static void keys_work_fn(struct work_struct *work)
> +{
> +	int i;
> +	static s32 prev_keys;
> +	struct rpisense_js *rpisense_js = &rpisense->joystick;
> +	s32 keys = rpisense_reg_read(rpisense, RPISENSE_KEYS);
> +	s32 changes = keys ^ prev_keys;
> +
> +	prev_keys = keys;
> +	for (i = 0; i < 5; i++) {
> +		if (changes & 1) {
> +			input_report_key(rpisense_js->keys_dev,
> +					 keymap[i], keys & 1);
> +		}
> +		changes >>= 1;
> +		keys >>= 1;
> +	}
> +	input_sync(rpisense_js->keys_dev);
> +}
> +
> +static irqreturn_t keys_irq_handler(int irq, void *pdev)
> +{
> +	struct rpisense_js *rpisense_js = &rpisense->joystick;
> +
> +	schedule_work(&rpisense_js->keys_work_s);
> +	return IRQ_HANDLED;
> +}
> +
> +static int rpisense_js_probe(struct platform_device *pdev)
> +{
> +	int ret;
> +	int i;
> +	struct rpisense_js *rpisense_js;
> +
> +	rpisense = rpisense_get_dev();
> +	rpisense_js = &rpisense->joystick;
> +
> +	INIT_WORK(&rpisense_js->keys_work_s, keys_work_fn);
> +
> +	rpisense_js->keys_dev = input_allocate_device();
> +	if (!rpisense_js->keys_dev) {
> +		dev_err(&pdev->dev, "Could not allocate input device.\n");
> +		return -ENOMEM;
> +	}
> +
> +	rpisense_js->keys_dev->evbit[0] = BIT_MASK(EV_KEY);
> +	for (i = 0; i < ARRAY_SIZE(keymap); i++) {
> +		set_bit(keymap[i],
> +			rpisense_js->keys_dev->keybit);
> +	}
> +
> +	rpisense_js->keys_dev->name = "Raspberry Pi Sense HAT Joystick";
> +	rpisense_js->keys_dev->phys = "rpi-sense-joy/input0";
> +	rpisense_js->keys_dev->id.bustype = BUS_I2C;
> +	rpisense_js->keys_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REP);
> +	rpisense_js->keys_dev->keycode = keymap;
> +	rpisense_js->keys_dev->keycodesize = sizeof(unsigned char);
> +	rpisense_js->keys_dev->keycodemax = ARRAY_SIZE(keymap);
> +
> +	ret = input_register_device(rpisense_js->keys_dev);
> +	if (ret) {
> +		dev_err(&pdev->dev, "Could not register input device.\n");
> +		goto err_keys_alloc;
> +	}
> +
> +	ret = gpiod_direction_input(rpisense_js->keys_desc);
> +	if (ret) {
> +		dev_err(&pdev->dev, "Could not set keys-int direction.\n");
> +		goto err_keys_reg;
> +	}
> +
> +	rpisense_js->keys_irq = gpiod_to_irq(rpisense_js->keys_desc);
> +	if (rpisense_js->keys_irq < 0) {
> +		dev_err(&pdev->dev, "Could not determine keys-int IRQ.\n");
> +		ret = rpisense_js->keys_irq;
> +		goto err_keys_reg;
> +	}
> +
> +	ret = devm_request_irq(&pdev->dev, rpisense_js->keys_irq,
> +			       keys_irq_handler, IRQF_TRIGGER_RISING,
> +			       "keys", &pdev->dev);
> +	if (ret) {
> +		dev_err(&pdev->dev, "IRQ request failed.\n");
> +		goto err_keys_reg;
> +	}
> +	return 0;
> +err_keys_reg:
> +	input_unregister_device(rpisense_js->keys_dev);
> +err_keys_alloc:
> +	input_free_device(rpisense_js->keys_dev);
> +	return ret;
> +}
> +
> +static int rpisense_js_remove(struct platform_device *pdev)
> +{
> +	struct rpisense_js *rpisense_js = &rpisense->joystick;
> +
> +	input_unregister_device(rpisense_js->keys_dev);
> +	input_free_device(rpisense_js->keys_dev);
> +	return 0;
> +}
> +
> +#ifdef CONFIG_OF
> +static const struct of_device_id rpisense_js_id[] = {
> +	{ .compatible = "raspberrypi,rpi-sense-js" },
> +	{ },
> +};
> +MODULE_DEVICE_TABLE(of, rpisense_js_id);
> +#endif
> +
> +static struct platform_device_id rpisense_js_device_id[] = {
> +	{ .name = "rpi-sense-js" },
> +	{ },
> +};
> +MODULE_DEVICE_TABLE(platform, rpisense_js_device_id);
> +
> +static struct platform_driver rpisense_js_driver = {
> +	.probe = rpisense_js_probe,
> +	.remove = rpisense_js_remove,
> +	.driver = {
> +		.name = "rpi-sense-js",
> +		.owner = THIS_MODULE,
please drop this line
> +	},
> +};
> +
> +module_platform_driver(rpisense_js_driver);
> +
> +MODULE_DESCRIPTION("Raspberry Pi Sense HAT joystick driver");
> +MODULE_AUTHOR("Serge Schneider <serge@raspberrypi.org>");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> index b74efa469e90..8c309e389359 100644
> --- a/drivers/mfd/Kconfig
> +++ b/drivers/mfd/Kconfig
> @@ -11,6 +11,14 @@ config MFD_CORE
>  	select IRQ_DOMAIN
>  	default n
>  
> +config MFD_RPISENSE_CORE
> +	tristate "Raspberry Pi Sense HAT core functions"
> +	depends on I2C
> +	select MFD_CORE
> +	help
> +	  This is the core driver for the Raspberry Pi Sense HAT. This provides
> +	  the necessary functions to communicate with the hardware.
> +
>  config MFD_CS5535
>  	tristate "AMD CS5535 and CS5536 southbridge core functions"
>  	select MFD_CORE
> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
> index 834f5463af28..7140a8fc36ee 100644
> --- a/drivers/mfd/Makefile
> +++ b/drivers/mfd/Makefile
> @@ -263,6 +263,7 @@ obj-$(CONFIG_MFD_ROHM_BD71828)	+= rohm-bd71828.o
>  obj-$(CONFIG_MFD_ROHM_BD718XX)	+= rohm-bd718x7.o
>  obj-$(CONFIG_MFD_STMFX) 	+= stmfx.o
>  obj-$(CONFIG_MFD_KHADAS_MCU) 	+= khadas-mcu.o
> +obj-$(CONFIG_MFD_RPISENSE_CORE) += rpisense-core.o
>  obj-$(CONFIG_MFD_ACER_A500_EC)	+= acer-ec-a500.o
>  
>  obj-$(CONFIG_SGI_MFD_IOC3)	+= ioc3.o
> diff --git a/drivers/mfd/rpisense-core.c b/drivers/mfd/rpisense-core.c
> new file mode 100644
> index 000000000000..aa2c394c5e67
> --- /dev/null
> +++ b/drivers/mfd/rpisense-core.c
> @@ -0,0 +1,162 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Raspberry Pi Sense HAT core driver
> + * http://raspberrypi.org
> + *
> + * Copyright (C) 2015 Raspberry Pi
> + *
> + * Author: Serge Schneider
> + * Adapted for mainline Linux by: Joel Savitz
> + *
> + *  This driver is based on wm8350 implementation.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/moduleparam.h>
> +#include <linux/err.h>
> +#include <linux/init.h>
> +#include <linux/i2c.h>
> +#include <linux/slab.h>
> +
> +#include <linux/mfd/rpisense.h>
> +
> +static struct rpisense *rpisense;
> +
> +static void rpisense_client_dev_register(struct rpisense *rpisense,
> +					 const char *name,
> +					 struct platform_device **pdev)
> +{
> +	int ret;
> +
> +	*pdev = platform_device_alloc(name, -1);
> +	if (*pdev == NULL) {
> +		dev_err(rpisense->dev, "Failed to allocate %s\n", name);
> +		return;
> +	}
> +
> +	(*pdev)->dev.parent = rpisense->dev;
> +	platform_set_drvdata(*pdev, rpisense);
> +	ret = platform_device_add(*pdev);
> +	if (ret != 0) {
> +		dev_err(rpisense->dev, "Failed to register %s: %d\n",
> +			name, ret);
> +		platform_device_put(*pdev);
> +		*pdev = NULL;
> +	}
> +}
> +
> +static int rpisense_probe(struct i2c_client *i2c,
> +			       const struct i2c_device_id *id)
> +{
> +	int ret;
> +	struct rpisense_js *rpisense_js;
> +
> +	rpisense = devm_kzalloc(&i2c->dev, sizeof(struct rpisense), GFP_KERNEL);
> +	if (rpisense == NULL)
> +		return -ENOMEM;
> +
> +	i2c_set_clientdata(i2c, rpisense);
> +	rpisense->dev = &i2c->dev;
> +	rpisense->i2c_client = i2c;
> +
> +	ret = rpisense_reg_read(rpisense, RPISENSE_WAI);
> +	if (ret > 0) {
> +		if (ret != 's')
> +			return -EINVAL;
this would be a good place for a error message like "Unable to detect
Raspberry Pi Sense HAT"
> +	} else {
> +		return ret;
> +	}
> +	ret = rpisense_reg_read(rpisense, RPISENSE_VER);
> +	if (ret < 0)
> +		return ret;
> +
> +	dev_info(rpisense->dev,
> +		 "Raspberry Pi Sense HAT firmware version %i\n", ret);
> +
> +	rpisense_js = &rpisense->joystick;
> +	rpisense_js->keys_desc = devm_gpiod_get(&i2c->dev,
> +						"keys-int", GPIOD_IN);
> +	if (IS_ERR(rpisense_js->keys_desc)) {
> +		dev_warn(&i2c->dev, "Failed to get keys-int descriptor.\n");
> +		rpisense_js->keys_desc = gpio_to_desc(23);
Unfortunately we cannot keep this fallback, because it's platform dependent.
> +		if (rpisense_js->keys_desc == NULL) {
> +			dev_err(&i2c->dev, "GPIO23 fallback failed.\n");
> +			return PTR_ERR(rpisense_js->keys_desc);
> +		}
> +	}
> +	rpisense_client_dev_register(rpisense, "rpi-sense-js",
> +				     &(rpisense->joystick.pdev));
> +	rpisense_client_dev_register(rpisense, "rpi-sense-fb",
> +				     &(rpisense->framebuffer.pdev));
> +
> +	return 0;
> +}
> +
> +static int rpisense_remove(struct i2c_client *i2c)
> +{
> +	struct rpisense *rpisense = i2c_get_clientdata(i2c);
> +
> +	platform_device_unregister(rpisense->joystick.pdev);
> +	return 0;
> +}
> +
> +struct rpisense *rpisense_get_dev(void)
> +{
> +	return rpisense;
> +}
> +EXPORT_SYMBOL_GPL(rpisense_get_dev);
> +
> +s32 rpisense_reg_read(struct rpisense *rpisense, int reg)
> +{
> +	int ret = i2c_smbus_read_byte_data(rpisense->i2c_client, reg);
> +
> +	if (ret < 0)
> +		dev_err(rpisense->dev, "Read from reg %d failed\n", reg);
> +	/* Due to the BCM270x I2C clock stretching bug, some values
In upstream BCM283x is the more common naming for the SoC
> +	 * may have MSB set. Clear it to avoid incorrect values.
> +	 */
> +	return ret & 0x7F;
> +}
> +EXPORT_SYMBOL_GPL(rpisense_reg_read);
> +
> +int rpisense_block_write(struct rpisense *rpisense, const char *buf, int count)
> +{
> +	int ret = i2c_master_send(rpisense->i2c_client, buf, count);
> +
> +	if (ret < 0)
> +		dev_err(rpisense->dev, "Block write failed\n");
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(rpisense_block_write);
> +
> +static const struct i2c_device_id rpisense_i2c_id[] = {
> +	{ "rpi-sense", 0 },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(i2c, rpisense_i2c_id);
> +
> +#ifdef CONFIG_OF
> +static const struct of_device_id rpisense_core_id[] = {
> +	{ .compatible = "raspberrypi,rpi-sense" },
> +	{ },
> +};
> +MODULE_DEVICE_TABLE(of, rpisense_core_id);
> +#endif
> +
> +
> +static struct i2c_driver rpisense_driver = {
> +	.driver = {
> +		   .name = "rpi-sense",
> +		   .owner = THIS_MODULE,
please drop this line


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^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2021-04-08 19:31 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-04-08  0:03 [RFC PATCH] drivers: Raspbery Pi Sense Hat Joel Savitz
2021-04-08  9:21 ` Peter Robinson
2021-04-08 16:16 ` Nicolas Saenz Julienne
2021-04-08 19:29 ` Stefan Wahren

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