drivers/i2c: sx9310: Replace register map with descriptive names

The current driver is using chip registers map to configure the SAR
sensor, which is opaque, especially when the datasheet is not published
widely.

Use more descriptive names, as defined in Linux kernel documentation at
https://www.kernel.org/doc/Documentation/devicetree/bindings/iio/proximity/semtech%2Csx9310.yaml

BUG=b:173341604
BRANCH=volteer
TEST=Dump all tables, check semtech property:
for i in $(find  /sys/firmware/acpi/tables/ -type f) ; do
 f=$(basename $i);  cat $i > /tmp/$f.dat ; iasl -d /tmp/$f.dat
done
In SSDT.dsl, we have:
Package (0x06)
 {
     Package (0x02)
     {
         "semtech,cs0-ground",
         Zero
     },
     Package (0x02)
     {
         "semtech,startup-sensor",
         Zero
     },
     Package (0x02)
     {
         "semtech,proxraw-strength",
         Zero
     },
     Package (0x02)
     {
         "semtech,avg-pos-strength",
         0x0200
     },
     Package (0x02)
     {
         "semtech,combined-sensors",
         Package (0x03)
         {
             Zero,
             One,
             0x02
         }
     },
     Package (0x02)
     {
         "semtech,resolution",
         "finest"
     }
 }

Change-Id: I8d1c81b56eaeef1dbb0f73c1d74c3a20e8b2fd7b
Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/50210
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>

3 files changed, 79 insertions, 40 deletions

diff --git a/src/drivers/i2c/sx9310/chip.h b/src/drivers/i2c/sx9310/chip.h
index 96690e32b4..3dcbcc4c15 100644
--- a/src/drivers/i2c/sx9310/chip.h
+++ b/src/drivers/i2c/sx9310/chip.h
@@ -6,7 +6,18 @@
 #include <acpi/acpi_device.h>
 #include <device/i2c_simple.h>
 
-#define REGISTER(NAME) uint8_t NAME
+#define MAX_COMBINED_SENSORS_ENTRIES 4
+
+enum sx9310_resolution {
+	SX9310_COARSEST = 1,
+	SX9310_VERY_COARSE,
+	SX9310_COARSE,
+	SX9310_MEDIUM_COARSE,
+	SX9310_MEDIUM,
+	SX9310_FINE,
+	SX9310_VERY_FINE,
+	SX9310_FINEST,
+};
 
 struct drivers_i2c_sx9310_config {
 	/* Device Description */
@@ -23,9 +34,34 @@ struct drivers_i2c_sx9310_config {
 
 	/* IO-APIC interrupt */
 	struct acpi_irq irq;
-#include "registers.h"
-};
 
-#undef REGISTER
+	/*
+	 * Registers definition in the kernel source tree at:
+	 * Documentation/devicetree/bindings/iio/proximity/semtech,sx9310.yaml
+	 */
+
+	/* When true, cs0 is the ground. 0 [default] is false. */
+	uint32_t cs0_ground;
+
+	/* Sensor used for start-up proximity detection: Default 0. */
+	uint32_t startup_sensor;
+
+	/* Raw Proximity filter strength: When not set, disabled. */
+	uint32_t proxraw_strength;
+
+	/* Average Proximity filter strength: When not set, disabled. */
+	uint32_t avg_pos_strength;
+
+	/*
+	 * List of which sensors are combined and represented by CS3.
+	 * Could be standalone (3) or combination of 0, 1, 2, 3.
+	 * Driver default: CS0 + CS1.
+	 */
+	uint32_t combined_sensors_count;
+	uint32_t combined_sensors[MAX_COMBINED_SENSORS_ENTRIES];
+
+	/* Capacitance measure resolution. Driver default: "finest". */
+	enum sx9310_resolution resolution;
+};
 
 #endif /* __DRIVERS_I2C_SX9310_CHIP_H__ */
diff --git a/src/drivers/i2c/sx9310/registers.h b/src/drivers/i2c/sx9310/registers.h
deleted file mode 100644
index 4744ae4c67..0000000000
--- a/src/drivers/i2c/sx9310/registers.h
+++ /dev/null
@@ -1,29 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-only */
-
-#ifndef REGISTER
-#error "define REGISTER(NAME) before including this file"
-#endif
-
-REGISTER(reg_prox_ctrl0);
-REGISTER(reg_prox_ctrl1);
-REGISTER(reg_prox_ctrl2);
-REGISTER(reg_prox_ctrl3);
-REGISTER(reg_prox_ctrl4);
-REGISTER(reg_prox_ctrl5);
-REGISTER(reg_prox_ctrl6);
-REGISTER(reg_prox_ctrl7);
-REGISTER(reg_prox_ctrl8);
-REGISTER(reg_prox_ctrl9);
-REGISTER(reg_prox_ctrl10);
-REGISTER(reg_prox_ctrl11);
-REGISTER(reg_prox_ctrl12);
-REGISTER(reg_prox_ctrl13);
-REGISTER(reg_prox_ctrl14);
-REGISTER(reg_prox_ctrl15);
-REGISTER(reg_prox_ctrl16);
-REGISTER(reg_prox_ctrl17);
-REGISTER(reg_prox_ctrl18);
-REGISTER(reg_prox_ctrl19);
-REGISTER(reg_sar_ctrl0);
-REGISTER(reg_sar_ctrl1);
-REGISTER(reg_sar_ctrl2);
diff --git a/src/drivers/i2c/sx9310/sx9310.c b/src/drivers/i2c/sx9310/sx9310.c
index 8dc57a2d98..d9e5a14c5b 100644
--- a/src/drivers/i2c/sx9310/sx9310.c
+++ b/src/drivers/i2c/sx9310/sx9310.c
@@ -12,9 +12,16 @@
 #define I2C_SX9310_ACPI_ID	"STH9310"
 #define I2C_SX9310_ACPI_NAME	"Semtech SX9310"
 
-#define REGISTER(NAME) acpi_dp_add_integer(dsd, \
-					I2C_SX9310_ACPI_ID "," #NAME, \
-					config->NAME)
+static const char * const i2c_sx9310_resolution[] = {
+	[SX9310_COARSEST] = "coarsest",
+	[SX9310_VERY_COARSE] = "very-coarse",
+	[SX9310_COARSE] = "coarse",
+	[SX9310_MEDIUM_COARSE] = "medium-coarse",
+	[SX9310_MEDIUM] = "medium",
+	[SX9310_FINE] = "fine",
+	[SX9310_VERY_FINE] = "very-fine",
+	[SX9310_FINEST] = "finest",
+};
 
 static void i2c_sx9310_fill_ssdt(const struct device *dev)
 {
@@ -27,6 +34,7 @@ static void i2c_sx9310_fill_ssdt(const struct device *dev)
 		.resource = scope,
 	};
 	struct acpi_dp *dsd;
+	struct acpi_dp *combined_sensors;
 
 	if (!scope || !config)
 		return;
@@ -56,9 +64,35 @@ static void i2c_sx9310_fill_ssdt(const struct device *dev)
 
 	/* DSD */
 	dsd = acpi_dp_new_table("_DSD");
-#include "registers.h"
-	acpi_dp_write(dsd);
 
+	/*
+	 * Format describe in linux kernel documentation. See
+	 * https://www.kernel.org/doc/Documentation/devicetree/bindings/iio/proximity/semtech%2Csx9310.yaml
+	 */
+	acpi_dp_add_integer(dsd, "semtech,cs0-ground", config->cs0_ground);
+	acpi_dp_add_integer(dsd, "semtech,startup-sensor",
+			config->startup_sensor);
+	acpi_dp_add_integer(dsd, "semtech,proxraw-strength",
+			config->proxraw_strength);
+	acpi_dp_add_integer(dsd, "semtech,avg-pos-strength",
+			config->avg_pos_strength);
+
+	/* Add combined_sensors package */
+	if (config->combined_sensors_count > 0) {
+		combined_sensors = acpi_dp_new_table("semtech,combined-sensors");
+		for (int i = 0;
+				i < config->combined_sensors_count &&
+				i < MAX_COMBINED_SENSORS_ENTRIES; ++i) {
+			acpi_dp_add_integer(combined_sensors, NULL,
+					    config->combined_sensors[i]);
+		}
+		acpi_dp_add_array(dsd, combined_sensors);
+	}
+	if (config->resolution && config->resolution < ARRAY_SIZE(i2c_sx9310_resolution))
+		acpi_dp_add_string(dsd, "semtech,resolution",
+				   i2c_sx9310_resolution[config->resolution]);
+
+	acpi_dp_write(dsd);
 	acpigen_pop_len(); /* Device */
 	acpigen_pop_len(); /* Scope */
 
@@ -66,8 +100,6 @@ static void i2c_sx9310_fill_ssdt(const struct device *dev)
 	       config->desc ? : dev->chip_ops->name, dev_path(dev));
 }
 
-#undef REGISTER
-
 static const char *i2c_sx9310_acpi_name(const struct device *dev)
 {
 	static char name[5];