Commit 3566a737 authored by Dmitry Baryshkov's avatar Dmitry Baryshkov Committed by Greg Kroah-Hartman
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nvmem: qfprom: switch to 4-byte aligned reads 



All platforms since Snapdragon 8 Gen1 (SM8450) require using 4-byte
reads to access QFPROM data. While older platforms were more than happy
with 1-byte reads, change the qfprom driver to use 4-byte reads for all
the platforms. Specify stride and word size of 4 bytes. To retain
compatibility with the existing DT and to simplify porting data from
vendor kernels, use fixup_dt_cell_info in order to bump alignment
requirements.

Signed-off-by: default avatarDmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: default avatarSrinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20250411112251.68002-12-srinivas.kandagatla@linaro.org


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 67864842

drivers/nvmem/qfprom.c

+20 −6
Original line number Diff line number Diff line
@@ -321,19 +321,32 @@ static int qfprom_reg_read(void *context, 
			unsigned int reg, void *_val, size_t bytes)

{

	struct qfprom_priv *priv = context;

	u8 *val = _val;

	int i = 0, words = bytes;

	u32 *val = _val;

	void __iomem *base = priv->qfpcorrected;

	int words = DIV_ROUND_UP(bytes, sizeof(u32));

	int i;



	if (read_raw_data && priv->qfpraw)

		base = priv->qfpraw;



	while (words--)

		*val++ = readb(base + reg + i++);

	for (i = 0; i < words; i++)

		*val++ = readl(base + reg + i * sizeof(u32));



	return 0;

}



/* Align reads to word boundary */

static void qfprom_fixup_dt_cell_info(struct nvmem_device *nvmem,

				      struct nvmem_cell_info *cell)

{

	unsigned int byte_offset = cell->offset % sizeof(u32);



	cell->bit_offset += byte_offset * BITS_PER_BYTE;

	cell->offset -= byte_offset;

	if (byte_offset && !cell->nbits)

		cell->nbits = cell->bytes * BITS_PER_BYTE;

}



static void qfprom_runtime_disable(void *data)

{

	pm_runtime_disable(data);
@@ -358,10 +371,11 @@ static int qfprom_probe(struct platform_device *pdev) 
	struct nvmem_config econfig = {

		.name = "qfprom",

		.add_legacy_fixed_of_cells = true,

		.stride = 1,

		.word_size = 1,

		.stride = 4,

		.word_size = 4,

		.id = NVMEM_DEVID_AUTO,

		.reg_read = qfprom_reg_read,

		.fixup_dt_cell_info = qfprom_fixup_dt_cell_info,

	};

	struct device *dev = &pdev->dev;

	struct resource *res;