kernel_5.10 no rt

hc

2023-12-11 6778948f9de86c3cfaf36725a7c87dcff9ba247f

 u-boot/drivers/input/spl_adc_key.c
..
..
@@ -6,28 +6,46 @@
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6
 
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 #include <common.h>
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 #include <adc.h>
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+#include <div64.h>
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 #include <fdtdec.h>
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+#include <dm/uclass.h>
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12
 
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 DECLARE_GLOBAL_DATA_PTR;
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+
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+static int adc_raw_to_mV(struct udevice *dev, unsigned int raw, int *mV)
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+{
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+	unsigned int data_mask;
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+	int ret, vref = 1800000;
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+	u64 raw64 = raw;
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+
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+	ret = adc_data_mask(dev, &data_mask);
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+	if (ret)
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+		return ret;
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+
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+	raw64 *= vref;
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+	do_div(raw64, data_mask);
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+	*mV = raw64;
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+
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+	return 0;
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+}
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 int key_read(int code)
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 {
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 	const void *fdt_blob = gd->fdt_blob;
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+	struct udevice *dev;
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 	int adc_node, offset;
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-	int cd, channel, adc;
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-	int ret, vref, mv;
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+	int t, down_threshold = -1, up_threshold;
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+	int ret, num = 0, volt_margin = 150000;	/* will be div 2 */
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+	int mV, cd, voltage = -1;
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 	int min, max;
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-	int margin;
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-	int range;
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-	uint val;
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-	u32 chn[2];
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-#ifdef CONFIG_SARADC_ROCKCHIP_V2
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-	range = 4096;	/* 12-bit adc */
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-	margin = 120;
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-#else
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-	range = 1024;	/* 10-bit adc */
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-	margin = 30;
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-#endif
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+	u32 chn[2], adc;
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+
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+	ret = uclass_get_device_by_name(UCLASS_ADC, "saradc", &dev);
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+	if (ret) {
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+		debug("No saradc device, ret=%d\n", ret);
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+		return 0;
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+	}
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+
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 	adc_node = fdt_node_offset_by_compatible(fdt_blob, 0, "adc-keys");
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 	if (adc_node < 0) {
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 		debug("No 'adc-keys' node, ret=%d\n", adc_node);
..
..
@@ -41,40 +59,87 @@
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 		return 0;
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 	}
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61
 
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-	vref = fdtdec_get_int(fdt_blob, adc_node,
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-			      "keyup-threshold-microvolt", -1);
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-	if (vref < 0) {
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+	up_threshold = fdtdec_get_int(fdt_blob, adc_node,
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+				      "keyup-threshold-microvolt", -ENODATA);
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+	if (up_threshold < 0) {
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 		debug("Can't read 'keyup-threshold-microvolt'\n");
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 		return 0;
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 	}
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68
 
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-	channel = chn[1];
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+	/* find the expected key-code */
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+	for (offset = fdt_first_subnode(fdt_blob, adc_node);
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+	     offset >= 0;
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+	     offset = fdt_next_subnode(fdt_blob, offset)) {
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+		cd = fdtdec_get_int(fdt_blob, offset, "linux,code", -ENODATA);
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+		if (cd < 0) {
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+			debug("Can't read 'linux,code', ret=%d\n", cd);
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+			return 0;
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+		}
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+
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+		if (cd == code) {
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+			voltage = fdtdec_get_int(fdt_blob, offset,
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+					"press-threshold-microvolt", -ENODATA);
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+			if (voltage < 0) {
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+				debug("Can't read 'press-threshold-microvolt'\n");
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+				return 0;
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+			}
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+			break;
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+		}
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+	}
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+
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+	if (voltage < 0)
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+		return 0;
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 	for (offset = fdt_first_subnode(fdt_blob, adc_node);
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 	     offset >= 0;
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 	     offset = fdt_next_subnode(fdt_blob, offset)) {
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-		cd = fdtdec_get_int(fdt_blob, offset, "linux,code", -1);
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-		if (cd == code) {
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-			mv = fdtdec_get_int(fdt_blob, offset,
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-					    "press-threshold-microvolt", -1);
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-			if (mv < 0) {
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-				debug("Can't read 'press-threshold-microvolt'\n");
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-				return 0;
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-			}
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-
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-			adc = mv / (vref / range);
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-			max = adc + margin;
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-			min = adc > margin ? adc - margin : 0;
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-			ret = adc_channel_single_shot("saradc", channel, &val);
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-			if (ret) {
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-				debug("Failed to read adc%d, ret=%d\n",
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-				      channel, ret);
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-				return 0;
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-			}
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-
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-			return (val >= min && val <= max);
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+		t = fdtdec_get_int(fdt_blob, offset,
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+				   "press-threshold-microvolt", -ENODATA);
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+		if (t < 0) {
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+			debug("Can't read 'press-threshold-microvolt'\n");
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+			return 0;
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 		}
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+
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+		if (t > voltage && t < up_threshold)
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+			up_threshold = t;
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+		else if (t < voltage && t > down_threshold)
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+			down_threshold = t;
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+		num++;
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 	}
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-	return 0;
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+	/* although one node only, it doesn't mean only one key on hardware */
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+	if (num == 1) {
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+		down_threshold = voltage - volt_margin;
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+		up_threshold = voltage + volt_margin;
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+	}
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+
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+	/*
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+	 * Define the voltage range such that the button is only pressed
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+	 * when the voltage is closest to its own press-threshold-microvolt
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+	 */
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+	if (down_threshold < 0)
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+		min = 0;
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+	else
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+		min = down_threshold + (voltage - down_threshold) / 2;
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+
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+	max = voltage + (up_threshold - voltage) / 2;
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+
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+	/* now, read key status */
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+	ret = adc_channel_single_shot("saradc", chn[1], &adc);
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+	if (ret) {
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+		debug("Failed to read adc%d, ret=%d\n", chn[1], ret);
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+		return 0;
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+	}
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+
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+	ret = adc_raw_to_mV(dev, adc, &mV);
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+	if (ret) {
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+		debug("Failed to convert adc to mV, ret=%d\n", ret);
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+		return 0;
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+	}
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+
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+	debug("key[%d] <%d, %d, %d>: adc=%d -> mV=%d\n",
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+	      code, min, voltage, max, adc, mV);
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+
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+	return (mV <= max && mV >= min);
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 }
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+