Allwinnner A13 / A23 / A33 based Q8 tablets are popular cheap 7" tablets
of which a new batch is produced every few weeks. Each batch uses a
different mix of touchscreen, accelerometer and wifi peripherals.
Given that each batch is different creating a devicetree for each variant
is not desirable. This commit adds a Q8 tablet hardware manager which
auto-detects the touchscreen and accelerometer so that a single generic
dts can be used for these tablets.
The wifi is connected to a discoverable bus (sdio or usb) and will be
autodetected by the mmc resp. usb subsystems.
Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
---
drivers/misc/Kconfig | 11 +
drivers/misc/Makefile | 1 +
drivers/misc/q8-hardwaremgr.c | 581 ++++++++++++++++++++++++++++++++++++++++++
3 files changed, 593 insertions(+)
create mode 100644 drivers/misc/q8-hardwaremgr.c
diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index d002528..d6c1529 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -794,6 +794,17 @@ config PANEL_BOOT_MESSAGE
An empty message will only clear the display at driver init time. Any other
printf()-formatted message is valid with newline and escape codes.
+config Q8_HARDWAREMGR
+ bool "Allwinner Q8 tablet hardware manager"
+ depends on I2C
+ depends on (ARCH_SUNXI && GPIOLIB && OF && OF_DYNAMIC) || COMPILE_TEST
+ default n
+ help
+ This option enables support for autodetecting the touchscreen
+ on Allwinner Q8 tablets.
+
+ If unsure, say N.
+
source "drivers/misc/c2port/Kconfig"
source "drivers/misc/eeprom/Kconfig"
source "drivers/misc/cb710/Kconfig"
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index fb32516..1a0ebb0 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -56,6 +56,7 @@ obj-$(CONFIG_ECHO) += echo/
obj-$(CONFIG_VEXPRESS_SYSCFG) += vexpress-syscfg.o
obj-$(CONFIG_CXL_BASE) += cxl/
obj-$(CONFIG_PANEL) += panel.o
+obj-$(CONFIG_Q8_HARDWAREMGR) += q8-hardwaremgr.o
lkdtm-$(CONFIG_LKDTM) += lkdtm_core.o
lkdtm-$(CONFIG_LKDTM) += lkdtm_bugs.o
diff --git a/drivers/misc/q8-hardwaremgr.c b/drivers/misc/q8-hardwaremgr.c
new file mode 100644
index 0000000..346102d
--- /dev/null
+++ b/drivers/misc/q8-hardwaremgr.c
@@ -0,0 +1,581 @@
+/*
+ * Allwinner q8 formfactor tablet hardware manager
+ *
+ * Copyright (C) 2016 Hans de Goede <hdegoede@xxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <asm/unaligned.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
+#include <linux/slab.h>
+
+/*
+ * We can detect which touchscreen controller is used automatically,
+ * but some controllers can be wired up differently depending on the
+ * q8 PCB variant used, so they need different firmware files / settings.
+ *
+ * We allow the user to specify a firmware_variant to select a config
+ * from a list of known configs. We also allow overriding each setting
+ * individually.
+ */
+
+static int touchscreen_variant = -1;
+module_param(touchscreen_variant, int, 0444);
+MODULE_PARM_DESC(touchscreen_variant, "Touchscreen variant 0-x, -1 for auto");
+
+static int touchscreen_width = -1;
+module_param(touchscreen_width, int, 0444);
+MODULE_PARM_DESC(touchscreen_width, "Touchscreen width, -1 for auto");
+
+static int touchscreen_height = -1;
+module_param(touchscreen_height, int, 0444);
+MODULE_PARM_DESC(touchscreen_height, "Touchscreen height, -1 for auto");
+
+static int touchscreen_invert_x = -1;
+module_param(touchscreen_invert_x, int, 0444);
+MODULE_PARM_DESC(touchscreen_invert_x, "Touchscreen invert x, -1 for auto");
+
+static int touchscreen_invert_y = -1;
+module_param(touchscreen_invert_y, int, 0444);
+MODULE_PARM_DESC(touchscreen_invert_y, "Touchscreen invert y, -1 for auto");
+
+static int touchscreen_swap_x_y = -1;
+module_param(touchscreen_swap_x_y, int, 0444);
+MODULE_PARM_DESC(touchscreen_swap_x_y, "Touchscreen swap x y, -1 for auto");
+
+static char *touchscreen_fw_name;
+module_param(touchscreen_fw_name, charp, 0444);
+MODULE_PARM_DESC(touchscreen_fw_name, "Touchscreen firmware filename");
+
+enum soc {
+ a13,
+ a23,
+ a33,
+};
+
+#define TOUCHSCREEN_POWER_ON_DELAY 20
+#define SILEAD_REG_ID 0xFC
+#define EKTF2127_RESPONSE 0x52
+#define EKTF2127_REQUEST 0x53
+#define EKTF2127_WIDTH 0x63
+
+enum {
+ touchscreen_unknown,
+ gsl1680_a082,
+ gsl1680_b482,
+ ektf2127,
+ zet6251,
+};
+
+struct q8_hardwaremgr_device {
+ int model;
+ int addr;
+ const char *compatible;
+ bool delete_regulator;
+};
+
+struct q8_hardwaremgr_data {
+ struct device *dev;
+ enum soc soc;
+ struct q8_hardwaremgr_device touchscreen;
+ int touchscreen_variant;
+ int touchscreen_width;
+ int touchscreen_height;
+ int touchscreen_invert_x;
+ int touchscreen_invert_y;
+ int touchscreen_swap_x_y;
+ const char *touchscreen_fw_name;
+};
+
+typedef int (*bus_probe_func)(struct q8_hardwaremgr_data *data,
+ struct i2c_adapter *adap);
+typedef int (*client_probe_func)(struct q8_hardwaremgr_data *data,
+ struct i2c_client *client);
+
+static struct device_node *q8_hardware_mgr_apply_common(
+ struct q8_hardwaremgr_device *dev, struct of_changeset *cset,
+ const char *prefix)
+{
+ struct device_node *np;
+
+ np = of_find_node_by_name(of_root, prefix);
+ /* Never happens already checked in q8_hardwaremgr_do_probe() */
+ if (WARN_ON(!np))
+ return NULL;
+
+ of_changeset_init(cset);
+ of_changeset_add_property_u32(cset, np, "reg", dev->addr);
+ of_changeset_add_property_string(cset, np, "compatible",
+ dev->compatible);
+ of_changeset_update_property_string(cset, np, "status", "okay");
+
+ if (dev->delete_regulator) {
+ struct property *p;
+
+ p = of_find_property(np, "vddio-supply", NULL);
+ /* Never happens already checked in q8_hardwaremgr_do_probe() */
+ if (WARN_ON(!p))
+ return np;
+
+ of_changeset_remove_property(cset, np, p);
+ }
+
+ return np; /* Allow the caller to make further changes */
+}
+
+static int q8_hardwaremgr_probe_client(struct q8_hardwaremgr_data *data,
+ struct q8_hardwaremgr_device *dev,
+ struct i2c_adapter *adap, u16 addr,
+ client_probe_func client_probe)
+{
+ struct i2c_client *client;
+ int ret;
+
+ client = i2c_new_dummy(adap, addr);
+ if (!client)
+ return -ENOMEM;
+
+ /* ret will be one of 0: Success, -ETIMEDOUT: Bus stuck or -ENODEV */
+ ret = client_probe(data, client);
+ if (ret == 0)
+ dev->addr = addr;
+
+ i2c_unregister_device(client);
+
+ return ret;
+}
+
+#define PROBE_CLIENT(dev, addr, probe) \
+{ \
+ int ret = q8_hardwaremgr_probe_client(data, dev, adap, addr, probe); \
+ if (ret != -ENODEV) \
+ return ret; \
+}
+
+static int q8_hardwaremgr_probe_silead(struct q8_hardwaremgr_data *data,
+ struct i2c_client *client)
+{
+ __le32 chip_id;
+ int ret;
+
+ ret = i2c_smbus_read_i2c_block_data(client, SILEAD_REG_ID,
+ sizeof(chip_id), (u8 *)&chip_id);
+ if (ret != sizeof(chip_id))
+ return ret == -ETIMEDOUT ? -ETIMEDOUT : -ENODEV;
+
+ switch (le32_to_cpu(chip_id)) {
+ case 0xa0820000:
+ data->touchscreen.compatible = "silead,gsl1680";
+ data->touchscreen.model = gsl1680_a082;
+ dev_info(data->dev, "Silead touchscreen ID: 0xa0820000\n");
+ return 0;
+ case 0xb4820000:
+ data->touchscreen.compatible = "silead,gsl1680";
+ data->touchscreen.model = gsl1680_b482;
+ dev_info(data->dev, "Silead touchscreen ID: 0xb4820000\n");
+ return 0;
+ default:
+ dev_warn(data->dev, "Silead? touchscreen with unknown ID: 0x%08x\n",
+ le32_to_cpu(chip_id));
+ }
+
+ return -ENODEV;
+}
+
+static int q8_hardwaremgr_probe_ektf2127(struct q8_hardwaremgr_data *data,
+ struct i2c_client *client)
+{
+ unsigned char buff[4];
+ int ret;
+
+ /* Read hello, ignore data, depends on initial power state */
+ ret = i2c_master_recv(client, buff, 4);
+ if (ret != 4)
+ return ret == -ETIMEDOUT ? -ETIMEDOUT : -ENODEV;
+
+ /* Request width */
+ buff[0] = EKTF2127_REQUEST;
+ buff[1] = EKTF2127_WIDTH;
+ buff[2] = 0x00;
+ buff[3] = 0x00;
+ ret = i2c_master_send(client, buff, 4);
+ if (ret != 4)
+ return ret == -ETIMEDOUT ? -ETIMEDOUT : -ENODEV;
+
+ msleep(20);
+
+ /* Read response */
+ ret = i2c_master_recv(client, buff, 4);
+ if (ret != 4)
+ return ret == -ETIMEDOUT ? -ETIMEDOUT : -ENODEV;
+
+ if (buff[0] == EKTF2127_RESPONSE && buff[1] == EKTF2127_WIDTH) {
+ data->touchscreen.compatible = "elan,ektf2127";
+ data->touchscreen.model = ektf2127;
+ return 0;
+ }
+
+ return -ENODEV;
+}
+
+static int q8_hardwaremgr_probe_zet6251(struct q8_hardwaremgr_data *data,
+ struct i2c_client *client)
+{
+ unsigned char buff[4];
+ int ret;
+
+ /*
+ * We only do a simple read finger data packet test, because some
+ * versions require firmware to be loaded. If no firmware is loaded
+ * the buffer will be filed with 0xff, so we ignore the contents.
+ */
+ ret = i2c_master_recv(client, buff, 24);
+ if (ret != 24)
+ return ret == -ETIMEDOUT ? -ETIMEDOUT : -ENODEV;
+
+ data->touchscreen.compatible = "zeitec,zet6251";
+ data->touchscreen.model = zet6251;
+ return 0;
+}
+
+static int q8_hardwaremgr_probe_touchscreen(struct q8_hardwaremgr_data *data,
+ struct i2c_adapter *adap)
+{
+ msleep(TOUCHSCREEN_POWER_ON_DELAY);
+
+ PROBE_CLIENT(&data->touchscreen, 0x40, q8_hardwaremgr_probe_silead);
+ PROBE_CLIENT(&data->touchscreen, 0x15, q8_hardwaremgr_probe_ektf2127);
+ PROBE_CLIENT(&data->touchscreen, 0x76, q8_hardwaremgr_probe_zet6251);
+
+ return -ENODEV;
+}
+
+static void q8_hardwaremgr_apply_gsl1680_a082_variant(
+ struct q8_hardwaremgr_data *data)
+{
+ if (touchscreen_variant != -1)
+ data->touchscreen_variant = touchscreen_variant;
+
+ switch (data->touchscreen_variant) {
+ default:
+ dev_warn(data->dev, "Error unknown touchscreen_variant %d using 0\n",
+ touchscreen_variant);
+ /* Fall through */
+ case 0:
+ data->touchscreen_width = 1024;
+ data->touchscreen_height = 600;
+ data->touchscreen_fw_name = "gsl1680-a082-q8-700.fw";
+ break;
+ case 1:
+ data->touchscreen_width = 480;
+ data->touchscreen_height = 800;
+ data->touchscreen_swap_x_y = 1;
+ data->touchscreen_fw_name = "gsl1680-a082-q8-a70.fw";
+ break;
+ }
+}
+
+static void q8_hardwaremgr_apply_gsl1680_b482_variant(
+ struct q8_hardwaremgr_data *data)
+{
+ if (touchscreen_variant != -1)
+ data->touchscreen_variant = touchscreen_variant;
+
+ switch (data->touchscreen_variant) {
+ default:
+ dev_warn(data->dev, "Error unknown touchscreen_variant %d using 0\n",
+ touchscreen_variant);
+ /* Fall through */
+ case 0:
+ data->touchscreen_width = 960;
+ data->touchscreen_height = 640;
+ data->touchscreen_fw_name = "gsl1680-b482-q8-d702.fw";
+ break;
+ case 1:
+ data->touchscreen_width = 960;
+ data->touchscreen_height = 640;
+ data->touchscreen_fw_name = "gsl1680-b482-q8-a70.fw";
+ break;
+ }
+}
+
+static void q8_hardwaremgr_issue_gsl1680_warning(
+ struct q8_hardwaremgr_data *data)
+{
+ dev_warn(data->dev, "gsl1680 touchscreen may require kernel cmdline parameters to function properly\n");
+ dev_warn(data->dev, "Try q8_hardwaremgr.touchscreen_invert_x=%d if x coordinates are inverted\n",
+ !data->touchscreen_invert_x);
+ dev_warn(data->dev, "Try q8_hardwaremgr.touchscreen_variant=%d if coordinates are all over the place\n",
+ !data->touchscreen_variant);
+
+#define show(x) \
+ dev_info(data->dev, #x " %d (%s)\n", data->x, \
+ (x == -1) ? "auto" : "user supplied")
+
+ show(touchscreen_variant);
+ show(touchscreen_width);
+ show(touchscreen_height);
+ show(touchscreen_invert_x);
+ show(touchscreen_invert_y);
+ show(touchscreen_swap_x_y);
+ dev_info(data->dev, "touchscreen_fw_name %s (%s)\n",
+ data->touchscreen_fw_name,
+ (touchscreen_fw_name == NULL) ? "auto" : "user supplied");
+#undef show
+}
+
+static void q8_hardwaremgr_apply_touchscreen(struct q8_hardwaremgr_data *data)
+{
+ struct of_changeset cset;
+ struct device_node *np;
+
+ switch (data->touchscreen.model) {
+ case touchscreen_unknown:
+ return;
+ case gsl1680_a082:
+ q8_hardwaremgr_apply_gsl1680_a082_variant(data);
+ break;
+ case gsl1680_b482:
+ q8_hardwaremgr_apply_gsl1680_b482_variant(data);
+ break;
+ case ektf2127:
+ case zet6251:
+ /* These have only 1 variant */
+ break;
+ }
+
+ if (touchscreen_width != -1)
+ data->touchscreen_width = touchscreen_width;
+
+ if (touchscreen_height != -1)
+ data->touchscreen_height = touchscreen_height;
+
+ if (touchscreen_invert_x != -1)
+ data->touchscreen_invert_x = touchscreen_invert_x;
+
+ if (touchscreen_invert_y != -1)
+ data->touchscreen_invert_y = touchscreen_invert_y;
+
+ if (touchscreen_swap_x_y != -1)
+ data->touchscreen_swap_x_y = touchscreen_swap_x_y;
+
+ if (touchscreen_fw_name)
+ data->touchscreen_fw_name = touchscreen_fw_name;
+
+ if (data->touchscreen.model == gsl1680_a082 ||
+ data->touchscreen.model == gsl1680_b482)
+ q8_hardwaremgr_issue_gsl1680_warning(data);
+
+ np = q8_hardware_mgr_apply_common(&data->touchscreen, &cset,
+ "touchscreen");
+ if (!np)
+ return;
+
+ if (data->touchscreen_width)
+ of_changeset_add_property_u32(&cset, np, "touchscreen-size-x",
+ data->touchscreen_width);
+ if (data->touchscreen_height)
+ of_changeset_add_property_u32(&cset, np, "touchscreen-size-y",
+ data->touchscreen_height);
+ if (data->touchscreen_invert_x)
+ of_changeset_add_property_bool(&cset, np,
+ "touchscreen-inverted-x");
+ if (data->touchscreen_invert_y)
+ of_changeset_add_property_bool(&cset, np,
+ "touchscreen-inverted-y");
+ if (data->touchscreen_swap_x_y)
+ of_changeset_add_property_bool(&cset, np,
+ "touchscreen-swapped-x-y");
+ if (data->touchscreen_fw_name)
+ of_changeset_add_property_string(&cset, np, "firmware-name",
+ data->touchscreen_fw_name);
+
+ of_changeset_apply(&cset);
+
+ of_node_put(np);
+}
+
+static int q8_hardwaremgr_do_probe(struct q8_hardwaremgr_data *data,
+ struct q8_hardwaremgr_device *dev,
+ const char *prefix, bus_probe_func func)
+{
+ struct device_node *np;
+ struct i2c_adapter *adap;
+ struct regulator *reg;
+ struct gpio_desc *gpio;
+ int ret = 0;
+
+ np = of_find_node_by_name(of_root, prefix);
+ if (!np) {
+ dev_err(data->dev, "Error %s node is missing\n", prefix);
+ return -EINVAL;
+ }
+
+ /*
+ * Patch the dt_node into our device since there is no device for
+ * the probed hw yet (status = disabled) .
+ */
+ data->dev->of_node = np;
+
+ ret = pinctrl_bind_pins(data->dev);
+ if (ret)
+ goto put_node;
+
+ adap = of_get_i2c_adapter_by_node(np->parent);
+ if (!adap) {
+ ret = -EPROBE_DEFER;
+ goto put_pins;
+ }
+
+ reg = regulator_get_optional(data->dev, "vddio");
+ if (IS_ERR(reg)) {
+ ret = PTR_ERR(reg);
+ if (ret == -EPROBE_DEFER)
+ goto put_adapter;
+ reg = NULL;
+ }
+
+ gpio = fwnode_get_named_gpiod(&np->fwnode, "power-gpios");
+ if (IS_ERR(gpio)) {
+ ret = PTR_ERR(gpio);
+ if (ret == -EPROBE_DEFER)
+ goto put_reg;
+ gpio = NULL;
+ }
+
+ /* First try with only the power gpio driven high */
+ if (gpio) {
+ ret = gpiod_direction_output(gpio, 1);
+ if (ret)
+ goto put_gpio;
+ }
+
+ dev_info(data->dev, "Probing %s without a regulator\n", prefix);
+ ret = func(data, adap);
+ if (ret != 0 && reg) {
+ /* Second try, also enable the regulator */
+ ret = regulator_enable(reg);
+ if (ret)
+ goto restore_gpio;
+
+ dev_info(data->dev, "Probing %s with a regulator\n", prefix);
+ ret = func(data, adap);
+
+ regulator_disable(reg);
+ } else if (reg)
+ dev->delete_regulator = true; /* Regulator not needed */
+
+ if (ret == 0)
+ dev_info(data->dev, "Found %s at 0x%02x\n",
+ dev->compatible, dev->addr);
+ else
+ ret = 0; /* Not finding a device is not an error */
+
+restore_gpio:
+ if (gpio)
+ gpiod_direction_output(gpio, 0);
+put_gpio:
+ if (gpio)
+ gpiod_put(gpio);
+put_reg:
+ if (reg)
+ regulator_put(reg);
+put_adapter:
+ i2c_put_adapter(adap);
+
+put_pins:
+ /* Undo our manual pinctrl_bind_pins() */
+ if (data->dev->pins) {
+ devm_pinctrl_put(data->dev->pins->p);
+ devm_kfree(data->dev, data->dev->pins);
+ data->dev->pins = NULL;
+ }
+
+put_node:
+ data->dev->of_node = NULL;
+ of_node_put(np);
+
+ return ret;
+}
+
+static int q8_hardwaremgr_probe(struct platform_device *pdev)
+{
+ struct q8_hardwaremgr_data *data;
+ int ret = 0;
+
+ data = kzalloc(sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ data->dev = &pdev->dev;
+ data->soc = (long)pdev->dev.platform_data;
+
+ ret = q8_hardwaremgr_do_probe(data, &data->touchscreen, "touchscreen",
+ q8_hardwaremgr_probe_touchscreen);
+ if (ret)
+ goto error;
+
+ q8_hardwaremgr_apply_touchscreen(data);
+
+error:
+ kfree(data);
+
+ return ret;
+}
+
+static struct platform_driver q8_hardwaremgr_driver = {
+ .driver = {
+ .name = "q8-hwmgr",
+ },
+ .probe = q8_hardwaremgr_probe,
+};
+
+static int __init q8_hardwaremgr_init(void)
+{
+ struct platform_device *pdev;
+ enum soc soc;
+ int ret;
+
+ if (of_machine_is_compatible("allwinner,q8-a13"))
+ soc = a13;
+ else if (of_machine_is_compatible("allwinner,q8-a23"))
+ soc = a23;
+ else if (of_machine_is_compatible("allwinner,q8-a33"))
+ soc = a33;
+ else
+ return 0;
+
+ pdev = platform_device_alloc("q8-hwmgr", 0);
+ if (!pdev)
+ return -ENOMEM;
+
+ pdev->dev.platform_data = (void *)(long)soc;
+
+ ret = platform_device_add(pdev);
+ if (ret)
+ return ret;
+
+ return platform_driver_register(&q8_hardwaremgr_driver);
+}
+
+device_initcall(q8_hardwaremgr_init);
+
+MODULE_DESCRIPTION("Allwinner q8 formfactor tablet hardware manager");
+MODULE_AUTHOR("Hans de Goede <hdegoede@xxxxxxxxxx>");
+MODULE_LICENSE("GPL");
--
2.9.3
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