Re: [PATCH v2] nvmem: add QTI SDAM driver
From: sthella
Date: Tue Jan 14 2020 - 23:56:05 EST
On 2019-12-23 16:22, Shyam Kumar Thella wrote:
From: Anirudh Ghayal <aghayal@xxxxxxxxxxxxxx>
QTI SDAM driver allows PMIC peripherals to access the shared memory
that is available on QTI PMICs.
Use subsys_initcall as PMIC SDAM NV memory is accessed by multiple PMIC
drivers (charger, fuel guage) to store/restore data across reboots
required during their initialization.
Signed-off-by: Shyam Kumar Thella <sthella@xxxxxxxxxxxxxx>
---
drivers/nvmem/Kconfig | 8 ++
drivers/nvmem/Makefile | 1 +
drivers/nvmem/qcom-spmi-sdam.c | 189
+++++++++++++++++++++++++++++++++++++++++
3 files changed, 198 insertions(+)
create mode 100644 drivers/nvmem/qcom-spmi-sdam.c
diff --git a/drivers/nvmem/Kconfig b/drivers/nvmem/Kconfig
index 73567e9..35efab1 100644
--- a/drivers/nvmem/Kconfig
+++ b/drivers/nvmem/Kconfig
@@ -109,6 +109,14 @@ config QCOM_QFPROM
This driver can also be built as a module. If so, the module
will be called nvmem_qfprom.
+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 ROCKCHIP_EFUSE
tristate "Rockchip eFuse Support"
depends on ARCH_ROCKCHIP || COMPILE_TEST
diff --git a/drivers/nvmem/Makefile b/drivers/nvmem/Makefile
index 9e66782..877a0b0 100644
--- a/drivers/nvmem/Makefile
+++ b/drivers/nvmem/Makefile
@@ -28,6 +28,7 @@ obj-$(CONFIG_MTK_EFUSE) += nvmem_mtk-efuse.o
nvmem_mtk-efuse-y := mtk-efuse.o
obj-$(CONFIG_QCOM_QFPROM) += nvmem_qfprom.o
nvmem_qfprom-y := qfprom.o
+obj-$(CONFIG_NVMEM_SPMI_SDAM) += qcom-spmi-sdam.o
obj-$(CONFIG_ROCKCHIP_EFUSE) += nvmem_rockchip_efuse.o
nvmem_rockchip_efuse-y := rockchip-efuse.o
obj-$(CONFIG_ROCKCHIP_OTP) += nvmem-rockchip-otp.o
diff --git a/drivers/nvmem/qcom-spmi-sdam.c
b/drivers/nvmem/qcom-spmi-sdam.c
new file mode 100644
index 0000000..e11228e
--- /dev/null
+++ b/drivers/nvmem/qcom-spmi-sdam.c
@@ -0,0 +1,189 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2017 The Linux Foundation. All rights reserved.
+ */
+
+#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;
+ struct nvmem_config sdam_config;
+ unsigned int base;
+ unsigned int size;
+};
+
+/* read only register offsets */
+static const u8 sdam_ro_map[] = {
+ REGISTER_MAP_ID,
+ REGISTER_MAP_VERSION,
+ SDAM_SIZE
+};
+
+static bool sdam_is_valid(struct sdam_chip *sdam, unsigned int offset,
+ size_t len)
+{
+ unsigned 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 sdam_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;
+ struct device *dev = &sdam->pdev->dev;
+ int rc;
+
+ if (!sdam_is_valid(sdam, offset, bytes)) {
+ dev_err(dev, "Invalid SDAM offset %#x len=%zd\n", offset, bytes);
+ return -EINVAL;
+ }
+
+ rc = regmap_bulk_read(sdam->regmap, sdam->base + offset, val, bytes);
+ if (rc < 0)
+ dev_err(dev, "Failed to read SDAM offset %#x 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;
+ struct device *dev = &sdam->pdev->dev;
+ int rc;
+
+ if (!sdam_is_valid(sdam, offset, bytes)) {
+ dev_err(dev, "Invalid SDAM offset %#x len=%zd\n", offset, bytes);
+ return -EINVAL;
+ }
+
+ if (sdam_is_ro(offset, bytes)) {
+ dev_err(dev, "Invalid write offset %#x len=%zd\n", offset, bytes);
+ return -EINVAL;
+ }
+
+ rc = regmap_bulk_write(sdam->regmap, sdam->base + offset, val,
bytes);
+ if (rc < 0)
+ dev_err(dev, "Failed to write SDAM offset %#x 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;
+ unsigned int val;
+ int rc;
+
+ sdam = devm_kzalloc(&pdev->dev, sizeof(*sdam), GFP_KERNEL);
+ if (!sdam)
+ return -ENOMEM;
+
+ sdam->regmap = dev_get_regmap(pdev->dev.parent, NULL);
+ if (!sdam->regmap) {
+ dev_err(&pdev->dev, "Failed to get regmap handle\n");
+ return -ENXIO;
+ }
+
+ rc = of_property_read_u32(pdev->dev.of_node, "reg", &sdam->base);
+ if (rc < 0) {
+ dev_err(&pdev->dev, "Failed to get SDAM base, rc=%d\n", rc);
+ return -EINVAL;
+ }
+
+ rc = regmap_read(sdam->regmap, sdam->base + SDAM_SIZE, &val);
+ if (rc < 0) {
+ dev_err(&pdev->dev, "Failed to read SDAM_SIZE rc=%d\n", rc);
+ return -EINVAL;
+ }
+ sdam->size = val * 32;
+
+ sdam->sdam_config.dev = &pdev->dev;
+ sdam->sdam_config.name = "spmi_sdam";
+ sdam->sdam_config.id = pdev->id;
+ sdam->sdam_config.owner = THIS_MODULE,
+ sdam->sdam_config.stride = 1;
+ sdam->sdam_config.word_size = 1;
+ sdam->sdam_config.reg_read = sdam_read;
+ sdam->sdam_config.reg_write = sdam_write;
+ sdam->sdam_config.priv = sdam;
+
+ nvmem = devm_nvmem_register(&pdev->dev, &sdam->sdam_config);
+ if (IS_ERR(nvmem)) {
+ dev_err(&pdev->dev,
+ "Failed to register SDAM nvmem device rc=%ld\n",
+ PTR_ERR(nvmem));
+ return -ENXIO;
+ }
+ dev_dbg(&pdev->dev,
+ "SDAM base=%#x size=%u registered successfully\n",
+ sdam->base, sdam->size);
+
+ return 0;
+}
+
+static const struct of_device_id sdam_match_table[] = {
+ { .compatible = "qcom,spmi-sdam" },
+ {},
+};
+
+static struct platform_driver sdam_driver = {
+ .driver = {
+ .name = "qcom,spmi-sdam",
+ .of_match_table = sdam_match_table,
+ },
+ .probe = sdam_probe,
+};
+
+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");
DT bindings for this driver is available at
https://lkml.org/lkml/2020/1/14/51
Regards,
Shyam