Merge "nvmem: qcom-spmi-sdam: Add support for SPMI SDAM"

Documentation/devicetree/bindings/nvmem/qcom-spmi-sdam.txt

@@ -0,0 +1,49 @@
+Qualcomm Technologies, Inc. Shared Direct Access Memory (SDAM)
+
+The SDAM provides scratch register space for the PMIC clients.
+This memory can be used by software to store information or communicate
+to/from the PBUS.
+
+Below are the DT bindings for this module
+
+Supported properties:
+
+- compatible
+  Usage:	required
+  Value type:	<string>
+  Definition:	Should be "qcom,spmi-sdam"
+
+- reg
+  Usage:	required
+  Value type:	<prop-encoded-array>
+  Definition:	The base address and size of the sdam peripheral.
+
+- Data cells
+  Usage:	required
+  Value type:	Subnodes with bindings described in bindings/nvmem/nvmem.txt.
+  Definition:	Cells defining the shared memory usage and configuration.
+
+Example:
+
+	sdam_1: sdam@b000 {
+		compatible = "qcom,spmi-sdam";
+		reg = <0xb000 0x100>;
+
+		....
+		/* Data cells */
+		restart_reason: restart@50 {
+			reg = <0x50 0x1>;
+			bits = <7 2>;
+		};
+	};
+
+= Data consumers =
+Are device nodes which consume nvmem data cells.
+
+Example:
+
+	{
+		...
+		nvmem-cells = <&restart_reason>;
+		nvmem-cell-names = "pmic_restart_reason";
+	};

drivers/nvmem/Kconfig

@@ -113,6 +113,14 @@ config NVMEM_BCM_OCOTP
 	  This driver can also be built as a module. If so, the module
 	  will be called nvmem-bcm-ocotp.
 
+config NVMEM_SPMI_SDAM
+	tristate "SPMI SDAM Support"
+	depends on SPMI
+	help
+	  This driver supports the Shared Direct Access Memory Module on
+	  Qualcomm Technologies, Inc. PMICs. It provides the clients
+	  an interface to read/write to the SDAM module's shared memory.
+
 config NVMEM_SUNXI_SID
 	tristate "Allwinner SoCs SID support"
 	depends on ARCH_SUNXI

drivers/nvmem/Makefile

@@ -25,6 +25,7 @@ obj-$(CONFIG_QCOM_QFPROM)	+= nvmem_qfprom.o
 nvmem_qfprom-y			:= qfprom.o
 obj-$(CONFIG_ROCKCHIP_EFUSE)	+= nvmem_rockchip_efuse.o
 nvmem_rockchip_efuse-y		:= rockchip-efuse.o
+obj-$(CONFIG_NVMEM_SPMI_SDAM)	+= qcom-spmi-sdam.o
 obj-$(CONFIG_NVMEM_SUNXI_SID)	+= nvmem_sunxi_sid.o
 nvmem_sunxi_sid-y		:= sunxi_sid.o
 obj-$(CONFIG_NVMEM_VF610_OCOTP)	+= nvmem-vf610-ocotp.o

drivers/nvmem/qcom-spmi-sdam.c

@@ -0,0 +1,205 @@
+/* Copyright (c) 2017 The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/nvmem-provider.h>
+#include <linux/regmap.h>
+
+#define SDAM_MEM_START			0x40
+#define REGISTER_MAP_ID			0x40
+#define REGISTER_MAP_VERSION		0x41
+#define SDAM_SIZE			0x44
+#define SDAM_PBS_TRIG_SET		0xE5
+#define SDAM_PBS_TRIG_CLR		0xE6
+
+struct sdam_chip {
+	struct platform_device		*pdev;
+	struct regmap			*regmap;
+	int				base;
+	int				size;
+};
+
+/* read only register offsets */
+static const u8 sdam_ro_map[] = {
+	REGISTER_MAP_ID,
+	REGISTER_MAP_VERSION,
+	SDAM_SIZE
+};
+
+static bool is_valid(struct sdam_chip *sdam, unsigned int offset, size_t len)
+{
+	int sdam_mem_end = SDAM_MEM_START + sdam->size - 1;
+
+	if (!len)
+		return false;
+
+	if (offset >= SDAM_MEM_START && offset <= sdam_mem_end
+				&& (offset + len - 1) <= sdam_mem_end)
+		return true;
+	else if ((offset == SDAM_PBS_TRIG_SET || offset == SDAM_PBS_TRIG_CLR)
+				&& (len == 1))
+		return true;
+
+	return false;
+}
+
+static bool is_ro(unsigned int offset, size_t len)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(sdam_ro_map); i++)
+		if (offset <= sdam_ro_map[i] && (offset + len) > sdam_ro_map[i])
+			return true;
+
+	return false;
+}
+
+static int sdam_read(void *priv, unsigned int offset, void *val, size_t bytes)
+{
+	struct sdam_chip *sdam = priv;
+	int rc;
+
+	if (!is_valid(sdam, offset, bytes)) {
+		pr_err("Invalid SDAM offset 0x%02x len=%zd\n", offset, bytes);
+		return -EINVAL;
+	}
+
+	rc = regmap_bulk_read(sdam->regmap, sdam->base + offset, val, bytes);
+	if (rc < 0)
+		pr_err("Failed to read SDAM offset 0x%02x len=%zd, rc=%d\n",
+						offset, bytes, rc);
+
+	return rc;
+}
+
+static int sdam_write(void *priv, unsigned int offset, void *val, size_t bytes)
+{
+	struct sdam_chip *sdam = priv;
+	int rc;
+
+	if (!is_valid(sdam, offset, bytes)) {
+		pr_err("Invalid SDAM offset 0x%02x len=%zd\n", offset, bytes);
+		return -EINVAL;
+	}
+
+	if (is_ro(offset, bytes)) {
+		pr_err("Invalid write offset 0x%02x len=%zd\n", offset, bytes);
+		return -EINVAL;
+	}
+
+	rc = regmap_bulk_write(sdam->regmap, sdam->base + offset, val, bytes);
+	if (rc < 0)
+		pr_err("Failed to write SDAM offset 0x%02x len=%zd, rc=%d\n",
+						offset, bytes, rc);
+
+	return rc;
+}
+
+static int sdam_probe(struct platform_device *pdev)
+{
+	struct sdam_chip *sdam;
+	struct nvmem_device *nvmem;
+	struct nvmem_config *sdam_config;
+	unsigned int val = 0;
+	int rc;
+
+	sdam = devm_kzalloc(&pdev->dev, sizeof(*sdam), GFP_KERNEL);
+	if (!sdam)
+		return -ENOMEM;
+
+	sdam_config = devm_kzalloc(&pdev->dev, sizeof(*sdam_config),
+							GFP_KERNEL);
+	if (!sdam_config)
+		return -ENOMEM;
+
+	sdam->regmap = dev_get_regmap(pdev->dev.parent, NULL);
+	if (!sdam->regmap) {
+		pr_err("Failed to get regmap handle\n");
+		return -ENXIO;
+	}
+
+	rc = of_property_read_u32(pdev->dev.of_node, "reg", &sdam->base);
+	if (rc < 0) {
+		pr_err("Failed to get SDAM base, rc=%d\n", rc);
+		return -EINVAL;
+	}
+
+	rc = regmap_read(sdam->regmap, sdam->base + SDAM_SIZE, &val);
+	if (rc < 0) {
+		pr_err("Failed to read SDAM_SIZE rc=%d\n", rc);
+		return -EINVAL;
+	}
+	sdam->size = val * 32;
+
+	sdam_config->dev = &pdev->dev;
+	sdam_config->name = "spmi_sdam";
+	sdam_config->id = pdev->id;
+	sdam_config->owner = THIS_MODULE,
+	sdam_config->stride = 1;
+	sdam_config->word_size = 1;
+	sdam_config->reg_read = sdam_read;
+	sdam_config->reg_write = sdam_write;
+	sdam_config->priv = sdam;
+
+	nvmem = nvmem_register(sdam_config);
+	if (IS_ERR(nvmem)) {
+		pr_err("Failed to register SDAM nvmem device rc=%ld\n",
+						PTR_ERR(nvmem));
+		return -ENXIO;
+	}
+	platform_set_drvdata(pdev, nvmem);
+
+	pr_info("SDAM base=0x%04x size=%d registered successfully\n",
+						sdam->base, sdam->size);
+
+	return 0;
+}
+
+static int sdam_remove(struct platform_device *pdev)
+{
+	struct nvmem_device *nvmem = platform_get_drvdata(pdev);
+
+	return nvmem_unregister(nvmem);
+}
+
+static const struct of_device_id sdam_match_table[] = {
+	{.compatible = "qcom,spmi-sdam"},
+	{},
+};
+
+static struct platform_driver sdam_driver = {
+	.driver = {
+		.name = "qcom,spmi-sdam",
+		.owner = THIS_MODULE,
+		.of_match_table = sdam_match_table,
+	},
+	.probe		= sdam_probe,
+	.remove		= sdam_remove,
+};
+
+static int __init sdam_init(void)
+{
+	return platform_driver_register(&sdam_driver);
+}
+subsys_initcall(sdam_init);
+
+static void __exit sdam_exit(void)
+{
+	return platform_driver_unregister(&sdam_driver);
+}
+module_exit(sdam_exit);
+
+MODULE_DESCRIPTION("QCOM SPMI SDAM driver");
+MODULE_LICENSE("GPL v2");