David Brownell :
[..]
Thanks! I'll be glad to see fewer versions of this driver floating around.
And to see the next version of the ads7843 patches ... :)
Hi,
Here is the ads7843 support for the ads7846 touchscreen driver. It is
very little and takes great advantage of the previous rework.
Tested on Atmel at91sam926[13]ek board with atmel_spi underlying driver.
I also put a use case based on the at91sam9263ek init code. This code is
just sent as an example, I will send those init patches trough AT91
maintainer.
Index: linux-2.6.20-at91/drivers/input/touchscreen/ads7846.c
===================================================================
--- linux-2.6.20-at91.orig/drivers/input/touchscreen/ads7846.c
+++ linux-2.6.20-at91/drivers/input/touchscreen/ads7846.c
@@ -39,7 +39,8 @@
/*
* This code has been heavily tested on a Nokia 770, and lightly
* tested on other ads7846 devices (OSK/Mistral, Lubbock).
- * Support for ads7843 and ads7845 has only been stubbed in.
+ * Support for ads7843 tested on Atmel at91sam926x-EK.
+ * Support for ads7845 has only been stubbed in.
*
* IRQ handling needs a workaround because of a shortcoming in handling
* edge triggered IRQs on some platforms like the OMAP1/2. These
@@ -246,18 +247,15 @@ static int ads7846_read12_ser(struct dev
/* REVISIT: take a few more samples, and compare ... */
- /* maybe off internal vREF */
- if (use_internal) {
- req->ref_off = REF_OFF;
- req->xfer[4].tx_buf = &req->ref_off;
- req->xfer[4].len = 1;
- spi_message_add_tail(&req->xfer[4], &req->msg);
-
- req->xfer[5].rx_buf = &req->scratch;
- req->xfer[5].len = 2;
- CS_CHANGE(req->xfer[5]);
- spi_message_add_tail(&req->xfer[5], &req->msg);
- }
+ req->ref_off = REF_OFF;
+ req->xfer[4].tx_buf = &req->ref_off;
+ req->xfer[4].len = 1;
+ spi_message_add_tail(&req->xfer[4], &req->msg);
+
+ req->xfer[5].rx_buf = &req->scratch;
+ req->xfer[5].len = 2;
+ CS_CHANGE(req->xfer[5]);
+ spi_message_add_tail(&req->xfer[5], &req->msg);
ts->irq_disabled = 1;
disable_irq(spi->irq);
@@ -536,6 +534,10 @@ static void ads7846_rx(void *ads)
} else
Rt = 0;
+ if (ts->model == 7843)
+ Rt = ts->pressure_max / 2;
+
+
/* Sample found inconsistent by debouncing or pressure is beyond
* the maximum. Don't report it to user space, repeat at least
* once more the measurement
Index: linux-2.6.20-at91/arch/arm/mach-at91rm9200/board-sam9263ek.c
===================================================================
--- linux-2.6.20-at91.orig/arch/arm/mach-at91rm9200/board-sam9263ek.c
+++ linux-2.6.20-at91/arch/arm/mach-at91rm9200/board-sam9263ek.c
@@ -25,6 +25,7 @@
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/spi/spi.h>
+#include <linux/spi/ads7846.h>
#include <asm/hardware.h>
#include <asm/setup.h>
@@ -84,6 +85,40 @@ static struct at91_udc_data __initdata e
.pullup_pin = 0, /* pull-up driven by UDC */
};
+/*
+ * Touchscreen ads7843
+ */
+#if defined(CONFIG_TOUCHSCREEN_ADS7846) ||
defined(CONFIG_TOUCHSCREEN_ADS7846_MODULE)
+
+int ads7843_pendown_state(void)
+{
+ return !at91_get_gpio_value(AT91_PIN_PA15);
+}
+
+static struct ads7846_platform_data ads_info = {
+ .model = 7843,
+ .x_min = 150, .x_max = 3830,
+ .y_min = 190, .y_max = 3830,
+ .vref_delay_usecs = 100,
+ .x_plate_ohms = 450,
+ .y_plate_ohms = 250,
+ .pressure_max = 15000,
+ .debounce_max = 1,
+ .debounce_rep = 0,
+ .debounce_tol = (~0),
+ .get_pendown_state = ads7843_pendown_state,
+};
+
+void __init at91_add_device_ts(void)
+{
+ /* Configure Interrupt 1 as external IRQ, with pullup */
+ at91_set_B_periph(AT91_PIN_PA15, 1); /* IRQ1 */
+ /* ts busy */
+ at91_set_gpio_input(AT91_PIN_PA31, 1);
+}
+#else
+void __init at91_add_device_ts(void) {}
+#endif
/*
* SPI devices.
@@ -97,6 +132,17 @@ static struct spi_board_info ek_spi_devi
.bus_num = 0,
},
#endif
+#if defined(CONFIG_TOUCHSCREEN_ADS7846) ||
defined(CONFIG_TOUCHSCREEN_ADS7846_MODULE)
+ {
+ .modalias = "ads7846",
+ .chip_select = 3,
+ .max_speed_hz = 125000 /* max sample rate at 3V */
+ * 26, /* command + data + overhead */
+ .bus_num = 0,
+ .platform_data = &ads_info,
+ .irq = AT91SAM9263_ID_IRQ1,
+ },
+#endif
};
@@ -164,6 +210,8 @@ static void __init ek_board_init(void)
at91_add_device_mmc(1, &ek_mmc_data);
/* NAND */
at91_add_device_nand(&ek_nand_data);
+ /* Touchscreen */
+ at91_add_device_ts();
}
MACHINE_START(AT91SAM9263EK, "Atmel AT91SAM9263-EK")
-
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