Input: goodix - add support for controllers without flash

Some Goodix touchscreen controllers, such as for example the GT912,
don't have flash-storage for their firmware.

These models require the OS to load the firmware at runtime, as well as
some other special handling. Add support for this to the goodix driver.

This patch was developed and tested on a Glavey TM800A550L tablet.

Note the "goodix,main-clk" and "firmware-name" device-properties used
by the new code are *not* documented in the
Documentation/devicetree/bindings/input/touchscreen/goodix.yaml
device-tree bindings for now.

Not documenting these is intentional. This is done because this code has
only been tested on x86/ACPI so far, where devicetree is not used.
Instead these properties are set through a software-fwnode attached to the
device by the drivers/platform/x86/touchscreen_dmi.c code. This means that
the use of this properties for now is purely a kernel-internal thing and
the name/working of the properties may still be changed for now.
Reviewed-by: Bastien Nocera <hadess@hadess.net>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20210920150643.155872-7-hdegoede@redhat.comSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/touchscreen/Makefile

@@ -6,6 +6,7 @@
 # Each configuration option enables a list of files.
 
 wm97xx-ts-y := wm97xx-core.o
+goodix_ts-y := goodix.o goodix_fwupload.o
 
 obj-$(CONFIG_TOUCHSCREEN_88PM860X)	+= 88pm860x-ts.o
 obj-$(CONFIG_TOUCHSCREEN_AD7877)	+= ad7877.o
@@ -44,7 +45,7 @@ obj-$(CONFIG_TOUCHSCREEN_EGALAX)	+= egalax_ts.o
 obj-$(CONFIG_TOUCHSCREEN_EGALAX_SERIAL)	+= egalax_ts_serial.o
 obj-$(CONFIG_TOUCHSCREEN_EXC3000)	+= exc3000.o
 obj-$(CONFIG_TOUCHSCREEN_FUJITSU)	+= fujitsu_ts.o
-obj-$(CONFIG_TOUCHSCREEN_GOODIX)	+= goodix.o
+obj-$(CONFIG_TOUCHSCREEN_GOODIX)	+= goodix_ts.o
 obj-$(CONFIG_TOUCHSCREEN_HIDEEP)	+= hideep.o
 obj-$(CONFIG_TOUCHSCREEN_ILI210X)	+= ili210x.o
 obj-$(CONFIG_TOUCHSCREEN_ILITEK)	+= ilitek_ts_i2c.o

drivers/input/touchscreen/goodix.c

@@ -326,6 +326,11 @@ static int goodix_ts_read_input_report(struct goodix_ts_data *ts, u8 *data)
 			return touch_num;
 		}
 
+		if (data[0] == 0 && ts->firmware_name) {
+			if (goodix_handle_fw_request(ts))
+				return 0;
+		}
+
 		usleep_range(1000, 2000); /* Poll every 1 - 2 ms */
 	} while (time_before(jiffies, max_timeout));
 
@@ -940,12 +945,19 @@ static void goodix_read_config(struct goodix_ts_data *ts)
 	int x_max, y_max;
 	int error;
 
-	error = goodix_i2c_read(ts->client, ts->chip->config_addr,
-				ts->config, ts->chip->config_len);
-	if (error) {
-		ts->int_trigger_type = GOODIX_INT_TRIGGER;
-		ts->max_touch_num = GOODIX_MAX_CONTACTS;
-		return;
+	/*
+	 * On controllers where we need to upload the firmware
+	 * (controllers without flash) ts->config already has the config
+	 * at this point and the controller itself does not have it yet!
+	 */
+	if (!ts->firmware_name) {
+		error = goodix_i2c_read(ts->client, ts->chip->config_addr,
+					ts->config, ts->chip->config_len);
+		if (error) {
+			ts->int_trigger_type = GOODIX_INT_TRIGGER;
+			ts->max_touch_num = GOODIX_MAX_CONTACTS;
+			return;
+		}
 	}
 
 	ts->int_trigger_type = ts->config[TRIGGER_LOC] & 0x03;
@@ -1139,7 +1151,16 @@ static void goodix_config_cb(const struct firmware *cfg, void *ctx)
 	struct goodix_ts_data *ts = ctx;
 	int error;
 
-	if (cfg) {
+	if (ts->firmware_name) {
+		if (!cfg)
+			goto err_release_cfg;
+
+		error = goodix_check_cfg(ts, cfg->data, cfg->size);
+		if (error)
+			goto err_release_cfg;
+
+		memcpy(ts->config, cfg->data, cfg->size);
+	} else if (cfg) {
 		/* send device configuration to the firmware */
 		error = goodix_send_cfg(ts, cfg->data, cfg->size);
 		if (error)
@@ -1231,6 +1252,10 @@ static int goodix_ts_probe(struct i2c_client *client,
 		return error;
 	}
 
+	error = goodix_firmware_check(ts);
+	if (error)
+		return error;
+
 	error = goodix_read_version(ts);
 	if (error)
 		return error;
@@ -1297,6 +1322,9 @@ static int __maybe_unused goodix_suspend(struct device *dev)
 	/* Free IRQ as IRQ pin is used as output in the suspend sequence */
 	goodix_free_irq(ts);
 
+	/* Save reference (calibration) info if necessary */
+	goodix_save_bak_ref(ts);
+
 	/* Output LOW on the INT pin for 5 ms */
 	error = goodix_irq_direction_output(ts, 0);
 	if (error) {

drivers/input/touchscreen/goodix.h

@@ -10,13 +10,48 @@
 #include <linux/regulator/consumer.h>
 
 /* Register defines */
+#define GOODIX_REG_MISCTL_DSP_CTL		0x4010
+#define GOODIX_REG_MISCTL_SRAM_BANK		0x4048
+#define GOODIX_REG_MISCTL_MEM_CD_EN		0x4049
+#define GOODIX_REG_MISCTL_CACHE_EN		0x404B
+#define GOODIX_REG_MISCTL_TMR0_EN		0x40B0
+#define GOODIX_REG_MISCTL_SWRST			0x4180
+#define GOODIX_REG_MISCTL_CPU_SWRST_PULSE	0x4184
+#define GOODIX_REG_MISCTL_BOOTCTL		0x4190
+#define GOODIX_REG_MISCTL_BOOT_OPT		0x4218
+#define GOODIX_REG_MISCTL_BOOT_CTL		0x5094
+
+#define GOODIX_REG_FW_SIG			0x8000
+#define GOODIX_FW_SIG_LEN			10
+
+#define GOODIX_REG_MAIN_CLK			0x8020
+#define GOODIX_MAIN_CLK_LEN			6
+
 #define GOODIX_REG_COMMAND			0x8040
 #define GOODIX_CMD_SCREEN_OFF			0x05
 
+#define GOODIX_REG_SW_WDT			0x8041
+
+#define GOODIX_REG_REQUEST			0x8043
+#define GOODIX_RQST_RESPONDED			0x00
+#define GOODIX_RQST_CONFIG			0x01
+#define GOODIX_RQST_BAK_REF			0x02
+#define GOODIX_RQST_RESET			0x03
+#define GOODIX_RQST_MAIN_CLOCK			0x04
+/*
+ * Unknown request which gets send by the controller aprox.
+ * every 34 seconds once it is up and running.
+ */
+#define GOODIX_RQST_UNKNOWN			0x06
+#define GOODIX_RQST_IDLE			0xFF
+
+#define GOODIX_REG_STATUS			0x8044
+
 #define GOODIX_GT1X_REG_CONFIG_DATA		0x8050
 #define GOODIX_GT9X_REG_CONFIG_DATA		0x8047
 #define GOODIX_REG_ID				0x8140
 #define GOODIX_READ_COOR_ADDR			0x814E
+#define GOODIX_REG_BAK_REF			0x99D0
 
 #define GOODIX_ID_MAX_LEN			4
 #define GOODIX_CONFIG_MAX_LENGTH		240
@@ -42,6 +77,7 @@ struct goodix_ts_data {
 	struct i2c_client *client;
 	struct input_dev *input_dev;
 	const struct goodix_chip_data *chip;
+	const char *firmware_name;
 	struct touchscreen_properties prop;
 	unsigned int max_touch_num;
 	unsigned int int_trigger_type;
@@ -62,6 +98,9 @@ struct goodix_ts_data {
 	unsigned int contact_size;
 	u8 config[GOODIX_CONFIG_MAX_LENGTH];
 	unsigned short keymap[GOODIX_MAX_KEYS];
+	u8 main_clk[GOODIX_MAIN_CLK_LEN];
+	int bak_ref_len;
+	u8 *bak_ref;
 };
 
 int goodix_i2c_read(struct i2c_client *client, u16 reg, u8 *buf, int len);
@@ -71,4 +110,8 @@ int goodix_send_cfg(struct goodix_ts_data *ts, const u8 *cfg, int len);
 int goodix_int_sync(struct goodix_ts_data *ts);
 int goodix_reset_no_int_sync(struct goodix_ts_data *ts);
 
+int goodix_firmware_check(struct goodix_ts_data *ts);
+bool goodix_handle_fw_request(struct goodix_ts_data *ts);
+void goodix_save_bak_ref(struct goodix_ts_data *ts);
+
 #endif