[PATCH] nvmem: add QTI SDAM driver

[PATCH] nvmem: add QTI SDAM driver

[Shyam Kumar Thella]

QTI SDAM driver allows PMIC peripherals to access the shared memory
that is available on QTI PMICs.

Change-Id: I40005646ab1fbba9e0e4aa68e0a61cfbc7b51ba6
Signed-off-by: Shyam Kumar Thella <sthella@codeaurora.org>
---
 drivers/nvmem/Kconfig          |   8 ++
 drivers/nvmem/Makefile         |   1 +
 drivers/nvmem/qcom-spmi-sdam.c | 197 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 206 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..e80a446
--- /dev/null
+++ b/drivers/nvmem/qcom-spmi-sdam.c
@@ -0,0 +1,197 @@
+// 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;
+	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",
+		.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");
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
 a Linux Foundation Collaborative Project

Re: [PATCH] nvmem: add QTI SDAM driver

[Bjorn Andersson]

On Tue 17 Dec 01:20 PST 2019, Shyam Kumar Thella wrote:

> QTI SDAM driver allows PMIC peripherals to access the shared memory
> that is available on QTI PMICs.
> 
> Change-Id: I40005646ab1fbba9e0e4aa68e0a61cfbc7b51ba6

No Change-Id upstream please.

> Signed-off-by: Shyam Kumar Thella <sthella@codeaurora.org>
[..]
> diff --git a/drivers/nvmem/qcom-spmi-sdam.c b/drivers/nvmem/qcom-spmi-sdam.c
> new file mode 100644
> index 0000000..e80a446
> --- /dev/null
> +++ b/drivers/nvmem/qcom-spmi-sdam.c
> @@ -0,0 +1,197 @@
> +// 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;

As written right now, pdev is unused. But if you stash struct device *
here instead you can replace your pr_err() with dev_err() using this,
for better error messages.

> +	struct regmap			*regmap;
> +	int				base;

This would look better as a unsigned int.

> +	int				size;

Ditto, or perhaps even size_t.

> +};
> +
> +/* 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)

Please do prefix this with "sdam_"

> +{
> +	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)

Ditto

> +{
> +	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);

Use %#x instead of 0x%02x

> +		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;

No need to initialize this.

> +	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);

Can't this be included in struct sdam_chip, for a single allocation?

> +	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");

dev_err(&pdev->dev, ...);

> +		return -ENXIO;
> +	}
> +
> +	rc = of_property_read_u32(pdev->dev.of_node, "reg", &sdam->base);

In other words, base must be u32.

> +	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);

Please don't print notifications in the kernel log. You can possibly use
dev_dbg(). Or just look for devices in
/sys/bus/platform/drivers/qcom,spmi-sdam/

> +
> +	return 0;
> +}
> +
> +static int sdam_remove(struct platform_device *pdev)

Instead of using nvmem_register(), use devm_nvmem_register() and just
omit the remote function completely - which also allows you to drop the
platform_set_drvdata() above.

> +{
> +	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"},

Please add a space after { and before }.

> +	{},
> +};
> +
> +static struct platform_driver sdam_driver = {
> +	.driver = {
> +		.name = "qcom,spmi-sdam",
> +		.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);

module_platform_driver(sdam_driver), unless you have some strong
arguments for why this needs to be subsys_initcall

Regards,
Bjorn

> +
> +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");
> -- 
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
>  a Linux Foundation Collaborative Project

Re: [PATCH] nvmem: add QTI SDAM driver

[sthella]

On 2019-12-18 11:44, Bjorn Andersson wrote:
> On Tue 17 Dec 01:20 PST 2019, Shyam Kumar Thella wrote:
> 
>> QTI SDAM driver allows PMIC peripherals to access the shared memory
>> that is available on QTI PMICs.
>> 
>> Change-Id: I40005646ab1fbba9e0e4aa68e0a61cfbc7b51ba6
> 
> No Change-Id upstream please.
OK. I will remove it in next patch set.
> 
>> Signed-off-by: Shyam Kumar Thella <sthella@codeaurora.org>
> [..]
>> diff --git a/drivers/nvmem/qcom-spmi-sdam.c 
>> b/drivers/nvmem/qcom-spmi-sdam.c
>> new file mode 100644
>> index 0000000..e80a446
>> --- /dev/null
>> +++ b/drivers/nvmem/qcom-spmi-sdam.c
>> @@ -0,0 +1,197 @@
>> +// 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;
> 
> As written right now, pdev is unused. But if you stash struct device *
> here instead you can replace your pr_err() with dev_err() using this,
> for better error messages.
> 
I will use dev_err messages in next patchset.
>> +	struct regmap			*regmap;
>> +	int				base;
> 
> This would look better as a unsigned int.
OK. I will do it in next patch set.
> 
>> +	int				size;
> 
> Ditto, or perhaps even size_t.
OK. I will do it.
> 
>> +};
>> +
>> +/* 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)
> 
> Please do prefix this with "sdam_"
OK. I will prefix is_valid and is_ro with "sdam_".
> 
>> +{
>> +	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)
> 
> Ditto
OK.
> 
>> +{
>> +	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);
> 
> Use %#x instead of 0x%02x
OK. Will do it in next patch set.
> 
>> +		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;
> 
> No need to initialize this.
OK. I will remove initialization in next patch set.
> 
>> +	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);
> 
> Can't this be included in struct sdam_chip, for a single allocation?
OK. I will make this a member in struct sdam_chip and eliminate need for 
dynamic allocation.
> 
>> +	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");
> 
> dev_err(&pdev->dev, ...);
OK. I will change all pr_err()... to dev_err().
> 
>> +		return -ENXIO;
>> +	}
>> +
>> +	rc = of_property_read_u32(pdev->dev.of_node, "reg", &sdam->base);
> 
> In other words, base must be u32.
OK. This will be changed to u32 in next patchs et.
> 
>> +	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);
> 
> Please don't print notifications in the kernel log. You can possibly 
> use
> dev_dbg(). Or just look for devices in
> /sys/bus/platform/drivers/qcom,spmi-sdam/
OK. I would usedev_dbg() to serve the purpose.
> 
>> +
>> +	return 0;
>> +}
>> +
>> +static int sdam_remove(struct platform_device *pdev)
> 
> Instead of using nvmem_register(), use devm_nvmem_register() and just
> omit the remote function completely - which also allows you to drop the
> platform_set_drvdata() above.
Yes. You are right. That will help omit remove and 
platform_set_drvdata().
> 
>> +{
>> +	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"},
> 
> Please add a space after { and before }.
OK. I will add spaces.
> 
>> +	{},
>> +};
>> +
>> +static struct platform_driver sdam_driver = {
>> +	.driver = {
>> +		.name = "qcom,spmi-sdam",
>> +		.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);
> 
> module_platform_driver(sdam_driver), unless you have some strong
> arguments for why this needs to be subsys_initcall
There are some critical sybsystems which depend on nvmem data. So I 
would prefer using subsys_initcall().
> 
> Regards,
> Bjorn
> 
>> +
>> +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");
>> --
>> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora 
>> Forum,
>>  a Linux Foundation Collaborative Project

Re: [PATCH] nvmem: add QTI SDAM driver

[Srinivas Kandagatla]

On 17/12/2019 09:20, Shyam Kumar Thella wrote:
> QTI SDAM driver allows PMIC peripherals to access the shared memory
> that is available on QTI PMICs.
> 
> Change-Id: I40005646ab1fbba9e0e4aa68e0a61cfbc7b51ba6
> Signed-off-by: Shyam Kumar Thella <sthella@codeaurora.org>
> ---
>   drivers/nvmem/Kconfig          |   8 ++
>   drivers/nvmem/Makefile         |   1 +
>   drivers/nvmem/qcom-spmi-sdam.c | 197 +++++++++++++++++++++++++++++++++++++++++
>   3 files changed, 206 insertions(+)
Not repeating comments from Bjorn,
Apart from that I have twos comment.

1>
Any reason why there is no Device tree bindings documented for this driver?

>   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..e80a446
> --- /dev/null
> +++ b/drivers/nvmem/qcom-spmi-sdam.c
> @@ -0,0 +1,197 @@

...
> +
> +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);
2>
May be devm_nvmem_register() here would  be better.


--srini

Re: [PATCH] nvmem: add QTI SDAM driver

[Bjorn Andersson]

On Thu 19 Dec 02:29 PST 2019, sthella@codeaurora.org wrote:

> On 2019-12-18 11:44, Bjorn Andersson wrote:
> > On Tue 17 Dec 01:20 PST 2019, Shyam Kumar Thella wrote:
[..]
> > > +subsys_initcall(sdam_init);
> > 
> > module_platform_driver(sdam_driver), unless you have some strong
> > arguments for why this needs to be subsys_initcall
> There are some critical sybsystems which depend on nvmem data. So I would
> prefer using subsys_initcall().

How critical? Needed to kernel module loading?

Can you please document this need somehow? (either a comment here or
something in the commit message). Be specific.

THanks,
Bjorn

Re: [PATCH] nvmem: add QTI SDAM driver

[sthella]

On 2019-12-20 05:59, Bjorn Andersson wrote:
> On Thu 19 Dec 02:29 PST 2019, sthella@codeaurora.org wrote:
> 
>> On 2019-12-18 11:44, Bjorn Andersson wrote:
>> > On Tue 17 Dec 01:20 PST 2019, Shyam Kumar Thella wrote:
> [..]
>> > > +subsys_initcall(sdam_init);
>> >
>> > module_platform_driver(sdam_driver), unless you have some strong
>> > arguments for why this needs to be subsys_initcall
>> There are some critical sybsystems which depend on nvmem data. So I 
>> would
>> prefer using subsys_initcall().
> 
> How critical? Needed to kernel module loading?
> 
> Can you please document this need somehow? (either a comment here or
> something in the commit message). Be specific.
Sure. I will add the need in commit message in its next patch.
> 
> THanks,
> Bjorn