5" Display For Raspberry Pi Pi2 Model B+ A+ used for OragePi 2

Jacaranda · Published in 2015-10-19 11:26:22

Edited by Jacaranda at 2015-10-19 18:53

You need compile ADS7846 touchscreen as a module.

fex:

[spi0]
spi_used = 1
spi_cs_bitmap = 1
spi_mosi = port:PC00<3><default><default><default>
spi_miso = port:PC01<3><default><default><default>
spi_sclk = port:PC02<3><default><default><default>
spi_cs0 = port:PA21<1><1><default><default>
[spi_devices]
spi_dev_num = 1
[spi_board0]
modalias = "ads7846"
max_speed_hz = 1500000
bus_num = 0
chip_select = 0
mode = 0
full_duplex = 1
manual_cs = 0

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drivers/input/touchscreen/ads7846.c:

diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads
index f02028e..0a3f610 100644
--- a/drivers/input/touchscreen/ads7846.c
+++ b/drivers/input/touchscreen/ads7846.c
@@ -59,6 +59,22 @@
#define TS_POLL_DELAY 1 /* ms delay before the first sample */
#define TS_POLL_PERIOD 5 /* ms delay between samples */
+
+static struct ads7846_platform_data ads7846_chip_info =
+{
+ .gpio_pendown = 2,
+ .pressure_max = 255,
+ .x_plate_ohms = 180,
+ .x_min = 176,
+ .x_max = 3913,
+ .y_min = 300,
+ .y_max = 3947,
+ .debounce_max = 10,
+ .debounce_tol = 3,
+ .debounce_rep = 1,
+ .keep_vref_on = 1
+};
+
/* this driver doesn't aim at the peak continuous sample rate */
#define SAMPLE_BITS (8 /*cmd*/ + 16 /*sample*/ + 2 /* before, after
@@ -970,6 +986,7 @@ static int __devinit ads7846_setup_pendown(struct spi_device
ts->get_pendown_state = pdata->get_pendown_state;
} else if (gpio_is_valid(pdata->gpio_pendown)) {
+ // try to get gpio for pendown
err = gpio_request_one(pdata->gpio_pendown, GPIOF_IN,
"ads7846_pendown");
if (err) {
@@ -1197,17 +1214,27 @@ static int __devinit ads7846_probe(struct spi_device *sp
struct ads7846 *ts;
struct ads7846_packet *packet;
struct input_dev *input_dev;
+
+ if (!spi->dev.platform_data) {
+ spi->dev.platform_data = &ads7846_chip_info;
+ }
+
struct ads7846_platform_data *pdata = spi->dev.platform_data;
unsigned long irq_flags;
int err;
- if (!spi->irq) {
- dev_dbg(&spi->dev, "no IRQ?\n");
+ if (!pdata) {
+ dev_dbg(&spi->dev, "no platform data?\n");
return -ENODEV;
}
- if (!pdata) {
- dev_dbg(&spi->dev, "no platform data?\n");
+ // try to grab irq for pendown
+ if (pdata->gpio_pendown) {
+ spi->irq = gpio_to_irq(pdata->gpio_pendown);
+ }
+
+ if (!spi->irq) {
+ dev_dbg(&spi->dev, "no IRQ?\n");
return -ENODEV;
}

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worked with PA21 - CS0 and PA02 - IRQ pendown.
Need some trics with platform_data, touch worked but no so cool.

Jacaranda · Published in 2015-10-19 11:51:49

platform_data in ads7846 driver module it's not true way. If any body know how made it right, please correct me. Thanks

Jacaranda · Published in 2015-10-19 16:59:30

Edited by Jacaranda at 2015-10-19 18:47

PA21 - is CS0 and PA02 - is IRQ for pendown You need turn off uart2 used PA02

[uart2]
uart_used = 0
uart_port = 2
uart_type = 4
uart_tx = port:PA00<2><1><default><default>
uart_rx = port:PA01<2><1><default><default>
uart_rts = port:PA02<2><1><default><default>
uart_cts = port:PA03<2><1><default><default>

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loboris · Published in 2015-10-19 20:02:09

Jacaranda replied at 2015-10-19 04:06
Wow thank you very much, can you share timig changes ?) thanks. Later i give driver code changes and ...

Thank you for sharing the code.
My display has USB touchscreen, but I would like to test the spi driver too.
You can get my sources at GitHub.

Jacaranda · Published in 2015-10-21 16:43:16

loboris replied at 2015-10-19 20:02
Thank you for sharing the code.
My display has USB touchscreen, but I would like to test the spi d ...

Thanks for sources all work perfect.

Maxikose · Published in 2015-12-18 21:18:55

Any idea how to get this display work with Android maybe Beelink_X2-SC_V1.1-Custom_ROM ? Its seems to be forced to use 1280x720 resolution...

igzero · Published in 2016-1-27 15:24:06

loboris replied at 2015-10-19 20:02
Thank you for sharing the code.
My display has USB touchscreen, but I would like to test the spi d ...

Hi!"Orange PI PC" will work with this display ( http://www.aliexpress.com/item/I ... MI/32583337754.html ) if I use your drivers?

zgoda · Published in 2016-2-4 04:35:50

This is HDMI connection interface for generic LCD display. For less than $30 I would try my luck.

leonidy-85 · Published in 2016-2-5 20:06:36

Jacaranda replied at 2015-10-19 07:51
platform_data in ads7846 driver module it's not true way. If any body know how made it right, please ...

Lay out please, the script.bin and ads7846.ko

tom1986 · Published in 2016-5-26 20:55:33

Hi, has anybody get this touchscreen working?