From: Nandor Han <nandor.han@vaisala.com>
To: srinivas.kandagatla@linaro.org, robh+dt@kernel.org,
linux-kernel@vger.kernel.org, devicetree@vger.kernel.org
Cc: Nandor Han <nandor.han@vaisala.com>
Subject: [PATCH v4 4/4] nvmem: snvs_lpgpr: support two bytes NVMEM cell size
Date: Wed, 5 May 2021 13:42:21 +0300 [thread overview]
Message-ID: <43cc83f7c8e2e3f5ba131b3c76ca7e30cd7e0f15.1620211180.git.nandor.han@vaisala.com> (raw)
In-Reply-To: <cover.1620211180.git.nandor.han@vaisala.com>
In some situation is desired to use less than 4 bytes for storing data.
This will allow using the same register for multiple purposes.
Add support for allowing 2 bytes granularity for NVMEM cells.
Signed-off-by: Nandor Han <nandor.han@vaisala.com>
---
drivers/nvmem/snvs_lpgpr.c | 67 ++++++++++++++++++++++++++++++++++----
1 file changed, 61 insertions(+), 6 deletions(-)
diff --git a/drivers/nvmem/snvs_lpgpr.c b/drivers/nvmem/snvs_lpgpr.c
index 35457421314a..44614f3d68f0 100644
--- a/drivers/nvmem/snvs_lpgpr.c
+++ b/drivers/nvmem/snvs_lpgpr.c
@@ -21,6 +21,9 @@
#define IMX_GPR_SL BIT(5)
#define IMX_GPR_HL BIT(5)
+#define REGMAP_FIELD_SIZE 16
+#define REGMAP_FIELDS_PER_REG 2
+
struct snvs_lpgpr_cfg {
int offset;
int offset_hplr;
@@ -33,6 +36,7 @@ struct snvs_lpgpr_priv {
struct regmap *regmap;
struct nvmem_config cfg;
const struct snvs_lpgpr_cfg *dcfg;
+ struct regmap_field **reg_fields;
};
static const struct snvs_lpgpr_cfg snvs_lpgpr_cfg_imx6q = {
@@ -56,6 +60,11 @@ static int snvs_lpgpr_write(void *context, unsigned int offset, void *val,
const struct snvs_lpgpr_cfg *dcfg = priv->dcfg;
unsigned int lock_reg;
int ret;
+ u32 regval;
+ unsigned int field_id;
+
+ if (offset + bytes > dcfg->size)
+ return -EINVAL;
ret = regmap_read(priv->regmap, dcfg->offset_hplr, &lock_reg);
if (ret < 0)
@@ -71,8 +80,16 @@ static int snvs_lpgpr_write(void *context, unsigned int offset, void *val,
if (lock_reg & IMX_GPR_HL)
return -EPERM;
- return regmap_bulk_write(priv->regmap, dcfg->offset + offset, val,
- bytes / priv->cfg.stride);
+ if (bytes == (REGMAP_FIELD_SIZE >> 3)) {
+ regval = *(u16 *)(val);
+ field_id = offset / REGMAP_FIELDS_PER_REG;
+ ret = regmap_field_write(priv->reg_fields[field_id], regval);
+ } else {
+ ret = regmap_bulk_write(priv->regmap, dcfg->offset + offset,
+ val, bytes / priv->cfg.stride);
+ }
+
+ return ret;
}
static int snvs_lpgpr_read(void *context, unsigned int offset, void *val,
@@ -80,9 +97,27 @@ static int snvs_lpgpr_read(void *context, unsigned int offset, void *val,
{
struct snvs_lpgpr_priv *priv = context;
const struct snvs_lpgpr_cfg *dcfg = priv->dcfg;
+ int ret;
+ u32 regval;
+ unsigned int field_id;
- return regmap_bulk_read(priv->regmap, dcfg->offset + offset, val,
- bytes / priv->cfg.stride);
+ if (offset + bytes > dcfg->size)
+ return -EINVAL;
+
+ if (bytes == (REGMAP_FIELD_SIZE >> 3)) {
+ field_id = offset / REGMAP_FIELDS_PER_REG;
+ ret = regmap_field_read(priv->reg_fields[field_id], ®val);
+ if (ret)
+ return ret;
+
+ *(u16 *)(val) = regval;
+ } else {
+ ret = regmap_bulk_read(priv->regmap, dcfg->offset + offset, val,
+ bytes / priv->cfg.stride);
+ if (ret)
+ return ret;
+ }
+ return 0;
}
static int snvs_lpgpr_probe(struct platform_device *pdev)
@@ -94,6 +129,8 @@ static int snvs_lpgpr_probe(struct platform_device *pdev)
struct nvmem_config *cfg;
struct nvmem_device *nvmem;
const struct snvs_lpgpr_cfg *dcfg;
+ int i;
+ int fields_count;
if (!node)
return -ENOENT;
@@ -121,13 +158,31 @@ static int snvs_lpgpr_probe(struct platform_device *pdev)
cfg->priv = priv;
cfg->name = dev_name(dev);
cfg->dev = dev;
- cfg->stride = 4;
- cfg->word_size = 4;
+ cfg->stride = 2;
+ cfg->word_size = 2;
cfg->size = dcfg->size;
cfg->owner = THIS_MODULE;
cfg->reg_read = snvs_lpgpr_read;
cfg->reg_write = snvs_lpgpr_write;
+ fields_count = priv->dcfg->size / priv->cfg.stride;
+ priv->reg_fields = devm_kzalloc(
+ dev, sizeof(struct regmap_field *) * fields_count, GFP_KERNEL);
+ if (!priv->reg_fields)
+ return -ENOMEM;
+
+ for (i = 0; i < fields_count; i++) {
+ size_t field_start = i * REGMAP_FIELD_SIZE;
+ size_t field_end = field_start + REGMAP_FIELD_SIZE - 1;
+ const struct reg_field field =
+ REG_FIELD(dcfg->offset, field_start, field_end);
+
+ priv->reg_fields[i] =
+ devm_regmap_field_alloc(dev, priv->regmap, field);
+ if (IS_ERR(priv->reg_fields[i]))
+ return PTR_ERR(priv->reg_fields[i]);
+ }
+
nvmem = devm_nvmem_register(dev, cfg);
return PTR_ERR_OR_ZERO(nvmem);
--
2.26.3
next prev parent reply other threads:[~2021-05-05 10:42 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-05 10:42 [PATCH v4 0/4] Bootcount driver using NVMEM cell as backend Nandor Han
2021-05-05 10:42 ` [PATCH v4 1/4] dt-bindings: nvmem: Add bootcount-nvmem Nandor Han
2021-05-05 10:42 ` [PATCH v4 2/4] nvmem: bootcount: add bootcount driver Nandor Han
2021-05-28 8:23 ` Srinivas Kandagatla
2021-06-01 7:58 ` Nandor Han
2021-06-03 8:03 ` Srinivas Kandagatla
2021-06-23 10:55 ` Vesa Jääskeläinen
2021-05-05 10:42 ` [PATCH v4 3/4] nvmem: snvs_lpgpr: use cell stride for regmap size calculation Nandor Han
2021-05-05 10:42 ` Nandor Han [this message]
2021-05-27 10:44 ` [PATCH v4 0/4] Bootcount driver using NVMEM cell as backend Nandor Han
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=43cc83f7c8e2e3f5ba131b3c76ca7e30cd7e0f15.1620211180.git.nandor.han@vaisala.com \
--to=nandor.han@vaisala.com \
--cc=devicetree@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=robh+dt@kernel.org \
--cc=srinivas.kandagatla@linaro.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).