Re: [PATCH v3 08/32] mtd: spi-nor: Pointer parameter for SR in spi_nor_read_sr()

Boris Brezillon
2019-10-31T10:51:44Z

On Tue, 29 Oct 2019 11:17:00 +0000
<Tudor.Ambarus@microchip.com> wrote:

> From: Tudor Ambarus <tudor.ambarus@microchip.com>
>
> Let the callers pass the pointer to the DMA-able buffer where
> the value of the Status Register will be written. This way we
> avoid the casts between int and u8, which can be confusing.
>
> Callers stop compare the return value of spi_nor_read_sr() with negative,
> spi_nor_read_sr() returns 0 on success and -errno otherwise.
>
> Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>

Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>

> ---
> drivers/mtd/spi-nor/spi-nor.c | 117 +++++++++++++++++++++++-------------------
> 1 file changed, 64 insertions(+), 53 deletions(-)
>
> diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
> index 1a00438fd061..dc44d1206f77 100644
> --- a/drivers/mtd/spi-nor/spi-nor.c
> +++ b/drivers/mtd/spi-nor/spi-nor.c
> @@ -425,12 +425,15 @@ static int spi_nor_write_disable(struct spi_nor *nor)
> return nor->controller_ops->write_reg(nor, SPINOR_OP_WRDI, NULL, 0);
> }
>
> -/*
> - * Read the status register, returning its value in the location
> - * Return the status register value.
> - * Returns negative if error occurred.
> +/**
> + * spi_nor_read_sr() - Read the Status Register.
> + * @nor: pointer to 'struct spi_nor'.
> + * @sr: pointer to a DMA-able buffer where the value of the
> + * Status Register will be written.
> + *
> + * Return: 0 on success, -errno otherwise.
> */
> -static int spi_nor_read_sr(struct spi_nor *nor)
> +static int spi_nor_read_sr(struct spi_nor *nor, u8 *sr)
> {
> int ret;
>
> @@ -439,20 +442,18 @@ static int spi_nor_read_sr(struct spi_nor *nor)
> SPI_MEM_OP(SPI_MEM_OP_CMD(SPINOR_OP_RDSR, 1),
> SPI_MEM_OP_NO_ADDR,
> SPI_MEM_OP_NO_DUMMY,
> - SPI_MEM_OP_DATA_IN(1, nor->bouncebuf, 1));
> + SPI_MEM_OP_DATA_IN(1, sr, 1));
>
> ret = spi_mem_exec_op(nor->spimem, &op);
> } else {
> ret = nor->controller_ops->read_reg(nor, SPINOR_OP_RDSR,
> - nor->bouncebuf, 1);
> + sr, 1);
> }
>
> - if (ret) {
> + if (ret)
> dev_err(nor->dev, "error %d reading SR\n", ret);
> - return ret;
> - }
>
> - return nor->bouncebuf[0];
> + return ret;
> }
>
> /*
> @@ -668,12 +669,14 @@ static int spi_nor_clear_sr(struct spi_nor *nor)
>
> static int spi_nor_sr_ready(struct spi_nor *nor)
> {
> - int sr = spi_nor_read_sr(nor);
> - if (sr < 0)
> - return sr;
> + int ret = spi_nor_read_sr(nor, &nor->bouncebuf[0]);
>
> - if (nor->flags & SNOR_F_USE_CLSR && sr & (SR_E_ERR | SR_P_ERR)) {
> - if (sr & SR_E_ERR)
> + if (ret)
> + return ret;
> +
> + if (nor->flags & SNOR_F_USE_CLSR &&
> + nor->bouncebuf[0] & (SR_E_ERR | SR_P_ERR)) {
> + if (nor->bouncebuf[0] & SR_E_ERR)
> dev_err(nor->dev, "Erase Error occurred\n");
> else
> dev_err(nor->dev, "Programming Error occurred\n");
> @@ -682,7 +685,7 @@ static int spi_nor_sr_ready(struct spi_nor *nor)
> return -EIO;
> }
>
> - return !(sr & SR_WIP);
> + return !(nor->bouncebuf[0] & SR_WIP);
> }
>
> static int spi_nor_clear_fsr(struct spi_nor *nor)
> @@ -831,11 +834,11 @@ static int spi_nor_write_sr_and_check(struct spi_nor *nor, u8 status_new,
> if (ret)
> return ret;
>
> - ret = spi_nor_read_sr(nor);
> - if (ret < 0)
> + ret = spi_nor_read_sr(nor, &nor->bouncebuf[0]);
> + if (ret)
> return ret;
>
> - return ((ret & mask) != (status_new & mask)) ? -EIO : 0;
> + return ((nor->bouncebuf[0] & mask) != (status_new & mask)) ? -EIO : 0;
> }
>
> static int spi_nor_write_sr2(struct spi_nor *nor, u8 *sr2)
> @@ -1510,16 +1513,18 @@ static int stm_is_unlocked_sr(struct spi_nor *nor, loff_t ofs, uint64_t len,
> static int stm_lock(struct spi_nor *nor, loff_t ofs, uint64_t len)
> {
> struct mtd_info *mtd = &nor->mtd;
> - int status_old, status_new;
> + int ret, status_old, status_new;
> u8 mask = SR_BP2 | SR_BP1 | SR_BP0;
> u8 shift = ffs(mask) - 1, pow, val;
> loff_t lock_len;
> bool can_be_top = true, can_be_bottom = nor->flags & SNOR_F_HAS_SR_TB;
> bool use_top;
>
> - status_old = spi_nor_read_sr(nor);
> - if (status_old < 0)
> - return status_old;
> + ret = spi_nor_read_sr(nor, &nor->bouncebuf[0]);
> + if (ret)
> + return ret;
> +
> + status_old = nor->bouncebuf[0];
>
> /* If nothing in our range is unlocked, we don't need to do anything */
> if (stm_is_locked_sr(nor, ofs, len, status_old))
> @@ -1590,16 +1595,18 @@ static int stm_lock(struct spi_nor *nor, loff_t ofs, uint64_t len)
> static int stm_unlock(struct spi_nor *nor, loff_t ofs, uint64_t len)
> {
> struct mtd_info *mtd = &nor->mtd;
> - int status_old, status_new;
> + int ret, status_old, status_new;
> u8 mask = SR_BP2 | SR_BP1 | SR_BP0;
> u8 shift = ffs(mask) - 1, pow, val;
> loff_t lock_len;
> bool can_be_top = true, can_be_bottom = nor->flags & SNOR_F_HAS_SR_TB;
> bool use_top;
>
> - status_old = spi_nor_read_sr(nor);
> - if (status_old < 0)
> - return status_old;
> + ret = spi_nor_read_sr(nor, &nor->bouncebuf[0]);
> + if (ret)
> + return ret;
> +
> + status_old = nor->bouncebuf[0];
>
> /* If nothing in our range is locked, we don't need to do anything */
> if (stm_is_unlocked_sr(nor, ofs, len, status_old))
> @@ -1674,13 +1681,13 @@ static int stm_unlock(struct spi_nor *nor, loff_t ofs, uint64_t len)
> */
> static int stm_is_locked(struct spi_nor *nor, loff_t ofs, uint64_t len)
> {
> - int status;
> + int ret;
>
> - status = spi_nor_read_sr(nor);
> - if (status < 0)
> - return status;
> + ret = spi_nor_read_sr(nor, &nor->bouncebuf[0]);
> + if (ret)
> + return ret;
>
> - return stm_is_locked_sr(nor, ofs, len, status);
> + return stm_is_locked_sr(nor, ofs, len, nor->bouncebuf[0]);
> }
>
> static const struct spi_nor_locking_ops stm_locking_ops = {
> @@ -1746,24 +1753,28 @@ static int spi_nor_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
> */
> static int macronix_quad_enable(struct spi_nor *nor)
> {
> - int ret, val;
> + int ret;
> +
> + ret = spi_nor_read_sr(nor, &nor->bouncebuf[0]);
> + if (ret)
> + return ret;
>
> - val = spi_nor_read_sr(nor);
> - if (val < 0)
> - return val;
> - if (val & SR_QUAD_EN_MX)
> + if (nor->bouncebuf[0] & SR_QUAD_EN_MX)
> return 0;
>
> spi_nor_write_enable(nor);
>
> - spi_nor_write_sr(nor, val | SR_QUAD_EN_MX);
> + spi_nor_write_sr(nor, nor->bouncebuf[0] | SR_QUAD_EN_MX);
>
> ret = spi_nor_wait_till_ready(nor);
> if (ret)
> return ret;
>
> - ret = spi_nor_read_sr(nor);
> - if (!(ret > 0 && (ret & SR_QUAD_EN_MX))) {
> + ret = spi_nor_read_sr(nor, &nor->bouncebuf[0]);
> + if (ret)
> + return ret;
> +
> + if (!(nor->bouncebuf[0] & SR_QUAD_EN_MX)) {
> dev_err(nor->dev, "Macronix Quad bit not set\n");
> return -EINVAL;
> }
> @@ -1835,12 +1846,12 @@ static int spansion_no_read_cr_quad_enable(struct spi_nor *nor)
> int ret;
>
> /* Keep the current value of the Status Register. */
> - ret = spi_nor_read_sr(nor);
> - if (ret < 0) {
> + ret = spi_nor_read_sr(nor, &sr_cr[0]);
> + if (ret) {
> dev_err(nor->dev, "error while reading status register\n");
> return ret;
> }
> - sr_cr[0] = ret;
> +
> sr_cr[1] = CR_QUAD_EN_SPAN;
>
> return spi_nor_write_sr_cr(nor, sr_cr);
> @@ -1878,12 +1889,11 @@ static int spansion_read_cr_quad_enable(struct spi_nor *nor)
> sr_cr[1] = ret | CR_QUAD_EN_SPAN;
>
> /* Keep the current value of the Status Register. */
> - ret = spi_nor_read_sr(nor);
> - if (ret < 0) {
> + ret = spi_nor_read_sr(nor, &sr_cr[0]);
> + if (ret) {
> dev_err(dev, "error while reading status register\n");
> return ret;
> }
> - sr_cr[0] = ret;
>
> ret = spi_nor_write_sr_cr(nor, sr_cr);
> if (ret)
> @@ -1967,15 +1977,15 @@ static int spi_nor_clear_sr_bp(struct spi_nor *nor)
> int ret;
> u8 mask = SR_BP2 | SR_BP1 | SR_BP0;
>
> - ret = spi_nor_read_sr(nor);
> - if (ret < 0) {
> + ret = spi_nor_read_sr(nor, &nor->bouncebuf[0]);
> + if (ret) {
> dev_err(nor->dev, "error while reading status register\n");
> return ret;
> }
>
> spi_nor_write_enable(nor);
>
> - ret = spi_nor_write_sr(nor, ret & ~mask);
> + ret = spi_nor_write_sr(nor, nor->bouncebuf[0] & ~mask);
> if (ret) {
> dev_err(nor->dev, "write to status register failed\n");
> return ret;
> @@ -2021,13 +2031,14 @@ static int spi_nor_spansion_clear_sr_bp(struct spi_nor *nor)
> if (ret & CR_QUAD_EN_SPAN) {
> sr_cr[1] = ret;
>
> - ret = spi_nor_read_sr(nor);
> - if (ret < 0) {
> + ret = spi_nor_read_sr(nor, &sr_cr[0]);
> + if (ret) {
> dev_err(nor->dev,
> "error while reading status register\n");
> return ret;
> }
> - sr_cr[0] = ret & ~mask;
> +
> + sr_cr[0] &= ~mask;
>
> ret = spi_nor_write_sr_cr(nor, sr_cr);
> if (ret)