mfd: qcom-spmi-pmic: expose the PMIC revid information to clients

Some PMIC functions such as the RRADC need to be aware of the PMIC
chip revision information to implement errata or otherwise adjust
behaviour, export the PMIC information to enable this.

This is specifically required to enable the RRADC to adjust
coefficients based on which chip fab the PMIC was produced in,
this can vary per unique device and therefore has to be read at
runtime.

Signed-off-by: Caleb Connolly <caleb.connolly@linaro.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Tested-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Acked-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20220429220904.137297-3-caleb.connolly@linaro.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

1 files changed, 175 insertions, 90 deletions

diff --git a/drivers/mfd/qcom-spmi-pmic.c b/drivers/mfd/qcom-spmi-pmic.c
index 1cacc00aa6c9..0f1f60e4daf7 100644
--- a/drivers/mfd/qcom-spmi-pmic.c
+++ b/drivers/mfd/qcom-spmi-pmic.c
@@ -3,11 +3,16 @@
  * Copyright (c) 2014, The Linux Foundation. All rights reserved.
  */
 
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/gfp.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/spmi.h>
+#include <linux/types.h>
 #include <linux/regmap.h>
 #include <linux/of_platform.h>
+#include <soc/qcom/qcom-spmi-pmic.h>
 
 #define PMIC_REV2		0x101
 #define PMIC_REV3		0x102
@@ -17,106 +22,140 @@
 
 #define PMIC_TYPE_VALUE		0x51
 
-#define COMMON_SUBTYPE		0x00
-#define PM8941_SUBTYPE		0x01
-#define PM8841_SUBTYPE		0x02
-#define PM8019_SUBTYPE		0x03
-#define PM8226_SUBTYPE		0x04
-#define PM8110_SUBTYPE		0x05
-#define PMA8084_SUBTYPE		0x06
-#define PMI8962_SUBTYPE		0x07
-#define PMD9635_SUBTYPE		0x08
-#define PM8994_SUBTYPE		0x09
-#define PMI8994_SUBTYPE		0x0a
-#define PM8916_SUBTYPE		0x0b
-#define PM8004_SUBTYPE		0x0c
-#define PM8909_SUBTYPE		0x0d
-#define PM8028_SUBTYPE		0x0e
-#define PM8901_SUBTYPE		0x0f
-#define PM8950_SUBTYPE		0x10
-#define PMI8950_SUBTYPE		0x11
-#define PM8998_SUBTYPE		0x14
-#define PMI8998_SUBTYPE		0x15
-#define PM8005_SUBTYPE		0x18
-#define PM660L_SUBTYPE		0x1A
-#define PM660_SUBTYPE		0x1B
-#define PM8150_SUBTYPE		0x1E
-#define PM8150L_SUBTYPE		0x1f
-#define PM8150B_SUBTYPE		0x20
-#define PMK8002_SUBTYPE		0x21
-#define PM8009_SUBTYPE		0x24
-#define PM8150C_SUBTYPE		0x26
-#define SMB2351_SUBTYPE		0x29
+#define PMIC_REV4_V2		0x02
+
+struct qcom_spmi_dev {
+	int num_usids;
+	struct qcom_spmi_pmic pmic;
+};
+
+#define N_USIDS(n)		((void *)n)
 
 static const struct of_device_id pmic_spmi_id_table[] = {
-	{ .compatible = "qcom,pm660",     .data = (void *)PM660_SUBTYPE },
-	{ .compatible = "qcom,pm660l",    .data = (void *)PM660L_SUBTYPE },
-	{ .compatible = "qcom,pm8004",    .data = (void *)PM8004_SUBTYPE },
-	{ .compatible = "qcom,pm8005",    .data = (void *)PM8005_SUBTYPE },
-	{ .compatible = "qcom,pm8019",    .data = (void *)PM8019_SUBTYPE },
-	{ .compatible = "qcom,pm8028",    .data = (void *)PM8028_SUBTYPE },
-	{ .compatible = "qcom,pm8110",    .data = (void *)PM8110_SUBTYPE },
-	{ .compatible = "qcom,pm8150",    .data = (void *)PM8150_SUBTYPE },
-	{ .compatible = "qcom,pm8150b",   .data = (void *)PM8150B_SUBTYPE },
-	{ .compatible = "qcom,pm8150c",   .data = (void *)PM8150C_SUBTYPE },
-	{ .compatible = "qcom,pm8150l",   .data = (void *)PM8150L_SUBTYPE },
-	{ .compatible = "qcom,pm8226",    .data = (void *)PM8226_SUBTYPE },
-	{ .compatible = "qcom,pm8841",    .data = (void *)PM8841_SUBTYPE },
-	{ .compatible = "qcom,pm8901",    .data = (void *)PM8901_SUBTYPE },
-	{ .compatible = "qcom,pm8909",    .data = (void *)PM8909_SUBTYPE },
-	{ .compatible = "qcom,pm8916",    .data = (void *)PM8916_SUBTYPE },
-	{ .compatible = "qcom,pm8941",    .data = (void *)PM8941_SUBTYPE },
-	{ .compatible = "qcom,pm8950",    .data = (void *)PM8950_SUBTYPE },
-	{ .compatible = "qcom,pm8994",    .data = (void *)PM8994_SUBTYPE },
-	{ .compatible = "qcom,pm8998",    .data = (void *)PM8998_SUBTYPE },
-	{ .compatible = "qcom,pma8084",   .data = (void *)PMA8084_SUBTYPE },
-	{ .compatible = "qcom,pmd9635",   .data = (void *)PMD9635_SUBTYPE },
-	{ .compatible = "qcom,pmi8950",   .data = (void *)PMI8950_SUBTYPE },
-	{ .compatible = "qcom,pmi8962",   .data = (void *)PMI8962_SUBTYPE },
-	{ .compatible = "qcom,pmi8994",   .data = (void *)PMI8994_SUBTYPE },
-	{ .compatible = "qcom,pmi8998",   .data = (void *)PMI8998_SUBTYPE },
-	{ .compatible = "qcom,pmk8002",   .data = (void *)PMK8002_SUBTYPE },
-	{ .compatible = "qcom,smb2351",   .data = (void *)SMB2351_SUBTYPE },
-	{ .compatible = "qcom,spmi-pmic", .data = (void *)COMMON_SUBTYPE },
+	{ .compatible = "qcom,pm660", .data = N_USIDS(2) },
+	{ .compatible = "qcom,pm660l", .data = N_USIDS(2) },
+	{ .compatible = "qcom,pm8004", .data = N_USIDS(2) },
+	{ .compatible = "qcom,pm8005", .data = N_USIDS(2) },
+	{ .compatible = "qcom,pm8019", .data = N_USIDS(2) },
+	{ .compatible = "qcom,pm8028", .data = N_USIDS(2) },
+	{ .compatible = "qcom,pm8110", .data = N_USIDS(2) },
+	{ .compatible = "qcom,pm8150", .data = N_USIDS(2) },
+	{ .compatible = "qcom,pm8150b", .data = N_USIDS(2) },
+	{ .compatible = "qcom,pm8150c", .data = N_USIDS(2) },
+	{ .compatible = "qcom,pm8150l", .data = N_USIDS(2) },
+	{ .compatible = "qcom,pm8226", .data = N_USIDS(2) },
+	{ .compatible = "qcom,pm8841", .data = N_USIDS(2) },
+	{ .compatible = "qcom,pm8901", .data = N_USIDS(2) },
+	{ .compatible = "qcom,pm8909", .data = N_USIDS(2) },
+	{ .compatible = "qcom,pm8916", .data = N_USIDS(2) },
+	{ .compatible = "qcom,pm8941", .data = N_USIDS(2) },
+	{ .compatible = "qcom,pm8950", .data = N_USIDS(2) },
+	{ .compatible = "qcom,pm8994", .data = N_USIDS(2) },
+	{ .compatible = "qcom,pm8998", .data = N_USIDS(2) },
+	{ .compatible = "qcom,pma8084", .data = N_USIDS(2) },
+	{ .compatible = "qcom,pmd9635", .data = N_USIDS(2) },
+	{ .compatible = "qcom,pmi8950", .data = N_USIDS(2) },
+	{ .compatible = "qcom,pmi8962", .data = N_USIDS(2) },
+	{ .compatible = "qcom,pmi8994", .data = N_USIDS(2) },
+	{ .compatible = "qcom,pmi8998", .data = N_USIDS(2) },
+	{ .compatible = "qcom,pmk8002", .data = N_USIDS(2) },
+	{ .compatible = "qcom,smb2351", .data = N_USIDS(2) },
+	{ .compatible = "qcom,spmi-pmic", .data = N_USIDS(1) },
 	{ }
 };
 
-static void pmic_spmi_show_revid(struct regmap *map, struct device *dev)
+/*
+ * A PMIC can be represented by multiple SPMI devices, but
+ * only the base PMIC device will contain a reference to
+ * the revision information.
+ *
+ * This function takes a pointer to a pmic device and
+ * returns a pointer to the base PMIC device.
+ *
+ * This only supports PMICs with 1 or 2 USIDs.
+ */
+static struct spmi_device *qcom_pmic_get_base_usid(struct device *dev)
 {
-	unsigned int rev2, minor, major, type, subtype;
-	const char *name = "unknown";
-	int ret, i;
+	struct spmi_device *sdev;
+	struct qcom_spmi_dev *ctx;
+	struct device_node *spmi_bus;
+	struct device_node *other_usid = NULL;
+	int function_parent_usid, ret;
+	u32 pmic_addr;
 
-	ret = regmap_read(map, PMIC_TYPE, &type);
-	if (ret < 0)
-		return;
+	sdev = to_spmi_device(dev);
+	ctx = dev_get_drvdata(&sdev->dev);
+
+	/*
+	 * Quick return if the function device is already in the base
+	 * USID. This will always be hit for PMICs with only 1 USID.
+	 */
+	if (sdev->usid % ctx->num_usids == 0)
+		return sdev;
 
-	if (type != PMIC_TYPE_VALUE)
-		return;
+	function_parent_usid = sdev->usid;
+
+	/*
+	 * Walk through the list of PMICs until we find the sibling USID.
+	 * The goal is to find the first USID which is less than the
+	 * number of USIDs in the PMIC array, e.g. for a PMIC with 2 USIDs
+	 * where the function device is under USID 3, we want to find the
+	 * device for USID 2.
+	 */
+	spmi_bus = of_get_parent(sdev->dev.of_node);
+	do {
+		other_usid = of_get_next_child(spmi_bus, other_usid);
+
+		ret = of_property_read_u32_index(other_usid, "reg", 0, &pmic_addr);
+		if (ret)
+			return ERR_PTR(ret);
+
+		sdev = spmi_device_from_of(other_usid);
+		if (pmic_addr == function_parent_usid - (ctx->num_usids - 1)) {
+			if (!sdev)
+				/*
+				 * If the base USID for this PMIC hasn't probed yet
+				 * but the secondary USID has, then we need to defer
+				 * the function driver so that it will attempt to
+				 * probe again when the base USID is ready.
+				 */
+				return ERR_PTR(-EPROBE_DEFER);
+			return sdev;
+		}
+	} while (other_usid->sibling);
+
+	return ERR_PTR(-ENODATA);
+}
+
+static int pmic_spmi_load_revid(struct regmap *map, struct device *dev,
+				 struct qcom_spmi_pmic *pmic)
+{
+	int ret;
 
-	ret = regmap_read(map, PMIC_SUBTYPE, &subtype);
+	ret = regmap_read(map, PMIC_TYPE, &pmic->type);
 	if (ret < 0)
-		return;
+		return ret;
 
-	for (i = 0; i < ARRAY_SIZE(pmic_spmi_id_table); i++) {
-		if (subtype == (unsigned long)pmic_spmi_id_table[i].data)
-			break;
-	}
+	if (pmic->type != PMIC_TYPE_VALUE)
+		return ret;
+
+	ret = regmap_read(map, PMIC_SUBTYPE, &pmic->subtype);
+	if (ret < 0)
+		return ret;
 
-	if (i != ARRAY_SIZE(pmic_spmi_id_table))
-		name = pmic_spmi_id_table[i].compatible;
+	pmic->name = of_match_device(pmic_spmi_id_table, dev)->compatible;
 
-	ret = regmap_read(map, PMIC_REV2, &rev2);
+	ret = regmap_read(map, PMIC_REV2, &pmic->rev2);
 	if (ret < 0)
-		return;
+		return ret;
 
-	ret = regmap_read(map, PMIC_REV3, &minor);
+	ret = regmap_read(map, PMIC_REV3, &pmic->minor);
 	if (ret < 0)
-		return;
+		return ret;
 
-	ret = regmap_read(map, PMIC_REV4, &major);
+	ret = regmap_read(map, PMIC_REV4, &pmic->major);
 	if (ret < 0)
-		return;
+		return ret;
 
 	/*
 	 * In early versions of PM8941 and PM8226, the major revision number
@@ -124,15 +163,49 @@ static void pmic_spmi_show_revid(struct regmap *map, struct device *dev)
 	 * Increment the major revision number here if the chip is an early
 	 * version of PM8941 or PM8226.
 	 */
-	if ((subtype == PM8941_SUBTYPE || subtype == PM8226_SUBTYPE) &&
-	    major < 0x02)
-		major++;
+	if ((pmic->subtype == PM8941_SUBTYPE || pmic->subtype == PM8226_SUBTYPE) &&
+	    pmic->major < PMIC_REV4_V2)
+		pmic->major++;
+
+	if (pmic->subtype == PM8110_SUBTYPE)
+		pmic->minor = pmic->rev2;
+
+	dev_dbg(dev, "%x: %s v%d.%d\n",
+		pmic->subtype, pmic->name, pmic->major, pmic->minor);
+
+	return 0;
+}
+
+/**
+ * qcom_pmic_get() - Get a pointer to the base PMIC device
+ *
+ * This function takes a struct device for a driver which is a child of a PMIC.
+ * And locates the PMIC revision information for it.
+ *
+ * @dev: the pmic function device
+ * @return: the struct qcom_spmi_pmic* pointer associated with the function device
+ */
+const struct qcom_spmi_pmic *qcom_pmic_get(struct device *dev)
+{
+	struct spmi_device *sdev;
+	struct qcom_spmi_dev *spmi;
+
+	/*
+	 * Make sure the device is actually a child of a PMIC
+	 */
+	if (!of_match_device(pmic_spmi_id_table, dev->parent))
+		return ERR_PTR(-EINVAL);
+
+	sdev = qcom_pmic_get_base_usid(dev->parent);
 
-	if (subtype == PM8110_SUBTYPE)
-		minor = rev2;
+	if (IS_ERR(sdev))
+		return ERR_CAST(sdev);
 
-	dev_dbg(dev, "%x: %s v%d.%d\n", subtype, name, major, minor);
+	spmi = dev_get_drvdata(&sdev->dev);
+
+	return &spmi->pmic;
 }
+EXPORT_SYMBOL(qcom_pmic_get);
 
 static const struct regmap_config spmi_regmap_config = {
 	.reg_bits	= 16,
@@ -144,14 +217,26 @@ static const struct regmap_config spmi_regmap_config = {
 static int pmic_spmi_probe(struct spmi_device *sdev)
 {
 	struct regmap *regmap;
+	struct qcom_spmi_dev *ctx;
+	int ret;
 
 	regmap = devm_regmap_init_spmi_ext(sdev, &spmi_regmap_config);
 	if (IS_ERR(regmap))
 		return PTR_ERR(regmap);
 
+	ctx = devm_kzalloc(&sdev->dev, sizeof(*ctx), GFP_KERNEL);
+	if (!ctx)
+		return -ENOMEM;
+
+	ctx->num_usids = (uintptr_t)of_device_get_match_data(&sdev->dev);
+
 	/* Only the first slave id for a PMIC contains this information */
-	if (sdev->usid % 2 == 0)
-		pmic_spmi_show_revid(regmap, &sdev->dev);
+	if (sdev->usid % ctx->num_usids == 0) {
+		ret = pmic_spmi_load_revid(regmap, &sdev->dev, &ctx->pmic);
+		if (ret < 0)
+			return ret;
+	}
+	spmi_device_set_drvdata(sdev, ctx);
 
 	return devm_of_platform_populate(&sdev->dev);
 }