[PATCH v3 8/9] nvmem: sfp: Use regmap

Sean Anderson
2022-04-28T18:18:05Z

This converts the SFP driver to use regmap. This will allow easily
supporting devices with different endians. We disallow byte-level
access, as regmap_bulk_read doesn't support it (and it's unclear what
the correct result would be when we have an endianness difference).

Signed-off-by: Sean Anderson <sean.anderson@seco.com>
---

(no changes since v2)

Changes in v2:
- New

drivers/nvmem/Kconfig | 1 +
drivers/nvmem/layerscape-sfp.c | 30 ++++++++++++++++++++++--------
2 files changed, 23 insertions(+), 8 deletions(-)

diff --git a/drivers/nvmem/Kconfig b/drivers/nvmem/Kconfig
index 555aa77a574d..403ed5257592 100644
--- a/drivers/nvmem/Kconfig
+++ b/drivers/nvmem/Kconfig
@@ -304,6 +304,7 @@ config NVMEM_LAYERSCAPE_SFP
tristate "Layerscape SFP (Security Fuse Processor) support"
depends on ARCH_LAYERSCAPE || COMPILE_TEST
depends on HAS_IOMEM
+ select REGMAP_MMIO
help
This driver provides support to read the eFuses on Freescale
Layerscape SoC's. For example, the vendor provides a per part
diff --git a/drivers/nvmem/layerscape-sfp.c b/drivers/nvmem/layerscape-sfp.c
index e591c1511e33..59083f048921 100644
--- a/drivers/nvmem/layerscape-sfp.c
+++ b/drivers/nvmem/layerscape-sfp.c
@@ -13,15 +13,17 @@
#include <linux/nvmem-provider.h>
#include <linux/platform_device.h>
#include <linux/property.h>
+#include <linux/regmap.h>

#define LAYERSCAPE_SFP_OTP_OFFSET 0x0200

struct layerscape_sfp_priv {
- void __iomem *base;
+ struct regmap *regmap;
};

struct layerscape_sfp_data {
int size;
+ enum regmap_endian endian;
};

static int layerscape_sfp_read(void *context, unsigned int offset, void *val,
@@ -29,15 +31,16 @@ static int layerscape_sfp_read(void *context, unsigned int offset, void *val,
{
struct layerscape_sfp_priv *priv = context;

- memcpy_fromio(val, priv->base + LAYERSCAPE_SFP_OTP_OFFSET + offset,
- bytes);
-
- return 0;
+ return regmap_bulk_read(priv->regmap,
+ LAYERSCAPE_SFP_OTP_OFFSET + offset, val,
+ bytes / 4);
}

static struct nvmem_config layerscape_sfp_nvmem_config = {
.name = "fsl-sfp",
.reg_read = layerscape_sfp_read,
+ .word_size = 4,
+ .stride = 4,
};

static int layerscape_sfp_probe(struct platform_device *pdev)
@@ -45,16 +48,26 @@ static int layerscape_sfp_probe(struct platform_device *pdev)
const struct layerscape_sfp_data *data;
struct layerscape_sfp_priv *priv;
struct nvmem_device *nvmem;
+ struct regmap_config config = { 0 };
+ void __iomem *base;

priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;

- priv->base = devm_platform_ioremap_resource(pdev, 0);
- if (IS_ERR(priv->base))
- return PTR_ERR(priv->base);
+ base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(base))
+ return PTR_ERR(base);

data = device_get_match_data(&pdev->dev);
+ config.reg_bits = 32;
+ config.reg_stride = 4;
+ config.val_bits = 32;
+ config.val_format_endian = data->endian;
+ config.max_register = LAYERSCAPE_SFP_OTP_OFFSET + data->size - 4;
+ priv->regmap = devm_regmap_init_mmio(&pdev->dev, base, &config);
+ if (IS_ERR(priv->regmap))
+ return PTR_ERR(priv->regmap);

layerscape_sfp_nvmem_config.size = data->size;
layerscape_sfp_nvmem_config.dev = &pdev->dev;
@@ -67,6 +80,7 @@ static int layerscape_sfp_probe(struct platform_device *pdev)

static const struct layerscape_sfp_data ls1028a_data = {
.size = 0x88,
+ .endian = REGMAP_ENDIAN_LITTLE,
};

static const struct of_device_id layerscape_sfp_dt_ids[] = {
--
2.35.1.1320.gc452695387.dirty