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// SPDX-License-Identifier: GPL-2.0
/*
* Raspberry Pi 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/of.h>
#include <linux/slab.h>
#include <linux/device.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/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 */
#define RPI_TS_NPOINTS_REG_INVALIDATE 99
struct rpi_ts {
struct platform_device *pdev;
struct input_dev *input;
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];
};
static void rpi_ts_poll(struct input_dev *input)
{
struct rpi_ts *ts = input_get_drvdata(input);
struct rpi_ts_regs regs;
int modified_ids = 0;
long released_ids;
int event_type;
int touchid;
int x, y;
int i;
memcpy_fromio(®s, ts->fw_regs_va, sizeof(regs));
/*
* 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)
*/
iowrite8(RPI_TS_NPOINTS_REG_INVALIDATE,
ts->fw_regs_va + offsetof(struct rpi_ts_regs, num_points));
if (regs.num_points == RPI_TS_NPOINTS_REG_INVALIDATE ||
(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;
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_dev *input;
struct device_node *fw_node;
struct rpi_firmware *fw;
struct rpi_ts *ts;
u32 touchbuf;
int error;
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)
return -ENOMEM;
ts->pdev = pdev;
ts->fw_regs_va = dma_alloc_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;
}
error = devm_add_action_or_reset(dev, rpi_ts_dma_cleanup, ts);
if (error) {
dev_err(dev, "failed to devm_add_action_or_reset, %d\n", error);
return error;
}
touchbuf = (u32)ts->fw_regs_phys;
error = rpi_firmware_property(fw, RPI_FIRMWARE_FRAMEBUFFER_SET_TOUCHBUF,
&touchbuf, sizeof(touchbuf));
if (error || touchbuf != 0) {
dev_warn(dev, "Failed to set touchbuf, %d\n", error);
return error;
}
input = devm_input_allocate_device(dev);
if (!input) {
dev_err(dev, "Failed to allocate input device\n");
return -ENOMEM;
}
ts->input = input;
input_set_drvdata(input, ts);
input->name = "raspberrypi-ts";
input->id.bustype = BUS_HOST;
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);
error = input_mt_init_slots(input, RPI_TS_MAX_SUPPORTED_POINTS,
INPUT_MT_DIRECT);
if (error) {
dev_err(dev, "could not init mt slots, %d\n", error);
return error;
}
error = input_setup_polling(input, rpi_ts_poll);
if (error) {
dev_err(dev, "could not set up polling mode, %d\n", error);
return error;
}
input_set_poll_interval(input, RPI_TS_POLL_INTERVAL);
error = input_register_device(input);
if (error) {
dev_err(dev, "could not register input device, %d\n", error);
return error;
}
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 firmware based touchscreen driver");
MODULE_LICENSE("GPL v2");
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