power: rpi-poe: Add option of being created by MFD or FW

The firmware can only use I2C0 if the kernel isn't, therefore
with libcamera and DRM using it the PoE HAT fan control needs
to move to the kernel.

Add the option for the driver to be created by the PoE HAT core
MFD driver, and use the I2C regmap that provides to control fan
functions.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>

diff --git a/drivers/power/supply/rpi_poe_power.c b/drivers/power/supply/rpi_poe_power.c
index 7cf1014..e96f98c 100644 (file)
--- a/drivers/power/supply/rpi_poe_power.c
+++ b/drivers/power/supply/rpi_poe_power.c
@@ -12,10 +12,13 @@
 #include <linux/of.h>
 #include <linux/platform_device.h>
 #include <linux/power_supply.h>
+#include <linux/regmap.h>
 #include <soc/bcm2835/raspberrypi-firmware.h>
 
-#define RPI_POE_ADC_REG                        0x2
-#define RPI_POE_FLAG_REG               0x4
+#define RPI_POE_FW_BASE_REG            0x2
+
+#define RPI_POE_ADC_REG                        0x0
+#define RPI_POE_FLAG_REG               0x2
 
 #define RPI_POE_FLAG_AT                        BIT(0)
 #define RPI_POE_FLAG_OC                        BIT(1)
@@ -26,8 +29,12 @@
 #define DRVNAME "rpi-poe-power-supply"
 
 struct rpi_poe_power_supply_ctx {
-       struct power_supply *supply;
        struct rpi_firmware *fw;
+
+       struct regmap *regmap;
+       u32 offset;
+
+       struct power_supply *supply;
 };
 
 struct fw_tag_data_s {
@@ -36,40 +43,51 @@ struct fw_tag_data_s {
        u32 ret;
 };
 
-static int write_reg(struct rpi_firmware *fw, u32 reg, u32 *val)
+static int write_reg(struct rpi_poe_power_supply_ctx *ctx, u32 reg, u32 *val)
 {
        struct fw_tag_data_s fw_tag_data = {
-               .reg = reg,
+               .reg = reg + RPI_POE_FW_BASE_REG,
                .val = *val
        };
        int ret;
 
-       ret = rpi_firmware_property(fw, RPI_FIRMWARE_SET_POE_HAT_VAL,
-                                   &fw_tag_data, sizeof(fw_tag_data));
-       if (ret)
-               return ret;
-       else if (fw_tag_data.ret)
-               return -EIO;
-       return 0;
+       if (ctx->fw) {
+               ret = rpi_firmware_property(ctx->fw, RPI_FIRMWARE_SET_POE_HAT_VAL,
+                                           &fw_tag_data, sizeof(fw_tag_data));
+               if (!ret && fw_tag_data.ret)
+                       ret = -EIO;
+       } else {
+               ret = regmap_write(ctx->regmap, ctx->offset + reg, *val);
+       }
+
+       return ret;
 }
 
-static int read_reg(struct rpi_firmware *fw, u32 reg, u32 *val)
+static int read_reg(struct rpi_poe_power_supply_ctx *ctx, u32 reg, u32 *val)
 {
        struct fw_tag_data_s fw_tag_data = {
-               .reg = reg,
+               .reg = reg + RPI_POE_FW_BASE_REG,
                .val = *val
        };
+       u32 value;
        int ret;
 
-       ret = rpi_firmware_property(fw, RPI_FIRMWARE_GET_POE_HAT_VAL,
-                                   &fw_tag_data, sizeof(fw_tag_data));
-       if (ret)
-               return ret;
-       else if (fw_tag_data.ret)
-               return -EIO;
+       if (ctx->fw) {
+               ret = rpi_firmware_property(ctx->fw, RPI_FIRMWARE_GET_POE_HAT_VAL,
+                                           &fw_tag_data, sizeof(fw_tag_data));
+               if (!ret && fw_tag_data.ret)
+                       ret = -EIO;
+               *val = fw_tag_data.val;
+       } else {
+               ret = regmap_read(ctx->regmap, ctx->offset + reg, &value);
+               if (!ret) {
+                       *val = value;
+                       ret = regmap_read(ctx->regmap, ctx->offset + reg + 1, &value);
+                       *val |= value << 8;
+               }
+       }
 
-       *val = fw_tag_data.val;
-       return 0;
+       return ret;
 }
 
 static int rpi_poe_power_supply_get_property(struct power_supply *psy,
@@ -82,14 +100,14 @@ static int rpi_poe_power_supply_get_property(struct power_supply *psy,
 
        switch (psp) {
        case POWER_SUPPLY_PROP_HEALTH:
-               ret = read_reg(ctx->fw, RPI_POE_FLAG_REG, &val);
+               ret = read_reg(ctx, RPI_POE_FLAG_REG, &val);
                if (ret)
                        return ret;
 
                if (val & RPI_POE_FLAG_OC) {
                        r_val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
                        val = RPI_POE_FLAG_OC;
-                       ret = write_reg(ctx->fw, RPI_POE_FLAG_REG, &val);
+                       ret = write_reg(ctx, RPI_POE_FLAG_REG, &val);
                        if (ret)
                                return ret;
                        return 0;
@@ -99,7 +117,7 @@ static int rpi_poe_power_supply_get_property(struct power_supply *psy,
                return 0;
 
        case POWER_SUPPLY_PROP_ONLINE:
-               ret = read_reg(ctx->fw, RPI_POE_ADC_REG, &val);
+               ret = read_reg(ctx, RPI_POE_ADC_REG, &val);
                if (ret)
                        return ret;
 
@@ -107,7 +125,7 @@ static int rpi_poe_power_supply_get_property(struct power_supply *psy,
                return 0;
 
        case POWER_SUPPLY_PROP_CURRENT_NOW:
-               ret = read_reg(ctx->fw, RPI_POE_ADC_REG, &val);
+               ret = read_reg(ctx, RPI_POE_ADC_REG, &val);
                if (ret)
                        return ret;
                val = (val * 3300)/9821;
@@ -115,15 +133,14 @@ static int rpi_poe_power_supply_get_property(struct power_supply *psy,
                return 0;
 
        case POWER_SUPPLY_PROP_CURRENT_MAX:
-               ret = read_reg(ctx->fw, RPI_POE_FLAG_REG, &val);
+               ret = read_reg(ctx, RPI_POE_FLAG_REG, &val);
                if (ret)
                        return ret;
 
-               if (val & RPI_POE_FLAG_AT) {
+               if (val & RPI_POE_FLAG_AT)
                        r_val->intval = RPI_POE_CURRENT_AT_MAX;
-                       return 0;
-               }
-               r_val->intval = RPI_POE_CURRENT_AF_MAX;
+               else
+                       r_val->intval = RPI_POE_CURRENT_AF_MAX;
                return 0;
 
        default:
@@ -158,29 +175,38 @@ static int rpi_poe_power_supply_probe(struct platform_device *pdev)
        if (!of_device_is_available(pdev->dev.of_node))
                return -ENODEV;
 
-       fw_node = of_parse_phandle(pdev->dev.of_node, "firmware", 0);
-       if (!fw_node) {
-               dev_err(&pdev->dev, "Missing firmware node\n");
-               return -ENOENT;
-       }
-
        ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL);
        if (!ctx)
                return -ENOMEM;
 
-       ctx->fw = rpi_firmware_get(fw_node);
-       if (!ctx->fw)
-               return -EPROBE_DEFER;
-       if (rpi_firmware_property(ctx->fw,
-                       RPI_FIRMWARE_GET_FIRMWARE_REVISION,
-                       &revision, sizeof(revision))) {
-               dev_err(&pdev->dev, "Failed to get firmware revision\n");
-               return -ENOENT;
-       }
-       if (revision < 0x60af72e8) {
-               dev_err(&pdev->dev, "Unsupported firmware\n");
-               return -ENOENT;
+       if (pdev->dev.parent)
+               ctx->regmap = dev_get_regmap(pdev->dev.parent, NULL);
+
+       if (ctx->regmap) {
+               if (device_property_read_u32(&pdev->dev, "reg", &ctx->offset))
+                       return -EINVAL;
+       } else {
+               fw_node = of_parse_phandle(pdev->dev.of_node, "firmware", 0);
+               if (!fw_node) {
+                       dev_err(&pdev->dev, "Missing firmware node\n");
+                       return -ENOENT;
+               }
+
+               ctx->fw = rpi_firmware_get(fw_node);
+               if (!ctx->fw)
+                       return -EPROBE_DEFER;
+               if (rpi_firmware_property(ctx->fw,
+                                         RPI_FIRMWARE_GET_FIRMWARE_REVISION,
+                                         &revision, sizeof(revision))) {
+                       dev_err(&pdev->dev, "Failed to get firmware revision\n");
+                       return -ENOENT;
+               }
+               if (revision < 0x60af72e8) {
+                       dev_err(&pdev->dev, "Unsupported firmware\n");
+                       return -ENOENT;
+               }
        }
+
        platform_set_drvdata(pdev, ctx);
 
        psy_cfg.of_node = pdev->dev.of_node;