iio: proximity: hx9023s: Added firmware file parsing functionality

Configuration information is now prioritized from the firmware file.
If the firmware file is missing or fails to parse, the driver falls
back to using the default configuration list for writing the settings.

Signed-off-by: Yasin Lee <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Jonathan Cameron <[e-mail]>

drivers/iio/proximity/hx9023s.c

···
 #include <linux/cleanup.h>
 #include <linux/device.h>
 #include <linux/errno.h>
+#include <linux/firmware.h>
 #include <linux/i2c.h>
 #include <linux/interrupt.h>
 #include <linux/irqreturn.h>
···
 #define HX9023S_DATA_LOCK_MASK BIT(4)
 #define HX9023S_INTERRUPT_MASK GENMASK(9, 0)
 #define HX9023S_PROX_DEBOUNCE_MASK GENMASK(3, 0)
+
+#define FW_VER_OFFSET 2
+#define FW_REG_CNT_OFFSET 3
+#define FW_DATA_OFFSET 16
+
+struct hx9023s_bin {
+	u16 reg_count;
+	u16 fw_size;
+	u8 fw_ver;
+	u8 data[] __counted_by(fw_size);
+};
 
 struct hx9023s_ch_data {
 	s16 raw; /* Raw Data*/
···
 	return 0;
 }
 
+static int hx9023s_bin_load(struct hx9023s_data *data, struct hx9023s_bin *bin)
+{
+	u8 *cfg_start = bin->data + FW_DATA_OFFSET;
+	u8 addr, val;
+	u16 i;
+	int ret;
+
+	for (i = 0; i < bin->reg_count; i++) {
+		addr = cfg_start[i * 2];
+		val = cfg_start[i * 2 + 1];
+		ret = regmap_write(data->regmap, addr, val);
+		if (ret < 0)
+			return ret;
+	}
+
+	return 0;
+}
+
+static int hx9023s_send_cfg(const struct firmware *fw, struct hx9023s_data *data)
+{
+	struct hx9023s_bin *bin __free(kfree) =
+		kzalloc(fw->size + sizeof(*bin), GFP_KERNEL);
+	if (!bin)
+		return -ENOMEM;
+
+	memcpy(bin->data, fw->data, fw->size);
+	release_firmware(fw);
+
+	bin->fw_size = fw->size;
+	bin->fw_ver = bin->data[FW_VER_OFFSET];
+	bin->reg_count = get_unaligned_le16(bin->data + FW_REG_CNT_OFFSET);
+
+	return hx9023s_bin_load(data, bin);
+}
+
+static void hx9023s_cfg_update(const struct firmware *fw, void *context)
+{
+	struct hx9023s_data *data = context;
+	struct device *dev = regmap_get_device(data->regmap);
+	int ret;
+
+	if (!fw || !fw->data) {
+		dev_warn(dev, "No firmware\n");
+		goto no_fw;
+	}
+
+	ret = hx9023s_send_cfg(fw, data);
+	if (ret) {
+		dev_warn(dev, "Firmware update failed: %d\n", ret);
+		goto no_fw;
+	}
+
+	ret = regcache_sync(data->regmap);
+	if (ret)
+		dev_err(dev, "regcache sync failed\n");
+
+	return;
+
+no_fw:
+	ret = regmap_multi_reg_write(data->regmap, hx9023s_reg_init_list,
+				     ARRAY_SIZE(hx9023s_reg_init_list));
+	if (ret) {
+		dev_err(dev, "Error loading default configuration\n");
+		return;
+	}
+
+	ret = regcache_sync(data->regmap);
+	if (ret)
+		dev_err(dev, "regcache sync failed\n");
+}
+
 static int hx9023s_probe(struct i2c_client *client)
 {
 	struct device *dev = &client->dev;
···
 	indio_dev->modes = INDIO_DIRECT_MODE;
 	i2c_set_clientdata(client, indio_dev);
 
-	ret = regmap_multi_reg_write(data->regmap, hx9023s_reg_init_list,
-				     ARRAY_SIZE(hx9023s_reg_init_list));
-	if (ret)
-		return dev_err_probe(dev, ret, "device init failed\n");
-
 	ret = hx9023s_ch_cfg(data);
 	if (ret)
 		return dev_err_probe(dev, ret, "channel config failed\n");
 
-	ret = regcache_sync(data->regmap);
+	ret = request_firmware_nowait(THIS_MODULE, true, "hx9023s.bin", dev,
+				      GFP_KERNEL, data, hx9023s_cfg_update);
 	if (ret)
-		return dev_err_probe(dev, ret, "regcache sync failed\n");
+		return dev_err_probe(dev, ret, "reg config failed\n");
 
 	if (client->irq) {
 		ret = devm_request_threaded_irq(dev, client->irq,