[PATCH v4 08/20] mtd: spi-nor-core: Rework hwcaps selection
Pratyush Yadav
p.yadav at ti.com
Fri May 22 14:44:57 CEST 2020
The spi-mem layer provides a spi_mem_supports_op() function to check
whether a specific operation is supported by the controller or not.
This is much more accurate than the hwcaps selection logic based on
SPI_{RX,TX}_ flags.
Rework the hwcaps selection logic to use spi_mem_supports_op().
Based on the Linux commit c76f5089796a (mtd: spi-nor: Rework hwcaps
selection for the spi-mem case, 2019-08-06)
Signed-off-by: Pratyush Yadav <p.yadav at ti.com>
---
drivers/mtd/spi/spi-nor-core.c | 168 +++++++++++++++++++++++++--------
include/linux/mtd/spi-nor.h | 14 +++
2 files changed, 144 insertions(+), 38 deletions(-)
diff --git a/drivers/mtd/spi/spi-nor-core.c b/drivers/mtd/spi/spi-nor-core.c
index fd99d88501..9db5bffa0a 100644
--- a/drivers/mtd/spi/spi-nor-core.c
+++ b/drivers/mtd/spi/spi-nor-core.c
@@ -2289,6 +2289,124 @@ static int spi_nor_hwcaps_pp2cmd(u32 hwcaps)
ARRAY_SIZE(hwcaps_pp2cmd));
}
+/**
+ * spi_nor_check_op - check if the operation is supported by controller
+ * @nor: pointer to a 'struct spi_nor'
+ * @op: pointer to op template to be checked
+ *
+ * Returns 0 if operation is supported, -ENOTSUPP otherwise.
+ */
+static int spi_nor_check_op(struct spi_nor *nor,
+ struct spi_mem_op *op)
+{
+ /*
+ * First test with 4 address bytes. The opcode itself might be a 3B
+ * addressing opcode but we don't care, because SPI controller
+ * implementation should not check the opcode, but just the sequence.
+ */
+ op->addr.nbytes = 4;
+ if (!spi_mem_supports_op(nor->spi, op)) {
+ if (nor->mtd.size > SZ_16M)
+ return -ENOTSUPP;
+
+ /* If flash size <= 16MB, 3 address bytes are sufficient */
+ op->addr.nbytes = 3;
+ if (!spi_mem_supports_op(nor->spi, op))
+ return -ENOTSUPP;
+ }
+
+ return 0;
+}
+
+/**
+ * spi_nor_check_readop - check if the read op is supported by controller
+ * @nor: pointer to a 'struct spi_nor'
+ * @read: pointer to op template to be checked
+ *
+ * Returns 0 if operation is supported, -ENOTSUPP otherwise.
+ */
+static int spi_nor_check_readop(struct spi_nor *nor,
+ const struct spi_nor_read_command *read)
+{
+ struct spi_mem_op op = SPI_MEM_OP(SPI_MEM_OP_CMD(read->opcode, 1),
+ SPI_MEM_OP_ADDR(3, 0, 1),
+ SPI_MEM_OP_DUMMY(0, 1),
+ SPI_MEM_OP_DATA_IN(0, NULL, 1));
+
+ op.cmd.buswidth = spi_nor_get_protocol_inst_nbits(read->proto);
+ op.addr.buswidth = spi_nor_get_protocol_addr_nbits(read->proto);
+ op.data.buswidth = spi_nor_get_protocol_data_nbits(read->proto);
+ op.dummy.buswidth = op.addr.buswidth;
+ op.dummy.nbytes = (read->num_mode_clocks + read->num_wait_states) *
+ op.dummy.buswidth / 8;
+
+ return spi_nor_check_op(nor, &op);
+}
+
+/**
+ * spi_nor_check_pp - check if the page program op is supported by controller
+ * @nor: pointer to a 'struct spi_nor'
+ * @pp: pointer to op template to be checked
+ *
+ * Returns 0 if operation is supported, -ENOTSUPP otherwise.
+ */
+static int spi_nor_check_pp(struct spi_nor *nor,
+ const struct spi_nor_pp_command *pp)
+{
+ struct spi_mem_op op = SPI_MEM_OP(SPI_MEM_OP_CMD(pp->opcode, 1),
+ SPI_MEM_OP_ADDR(3, 0, 1),
+ SPI_MEM_OP_NO_DUMMY,
+ SPI_MEM_OP_DATA_OUT(0, NULL, 1));
+
+ op.cmd.buswidth = spi_nor_get_protocol_inst_nbits(pp->proto);
+ op.addr.buswidth = spi_nor_get_protocol_addr_nbits(pp->proto);
+ op.data.buswidth = spi_nor_get_protocol_data_nbits(pp->proto);
+
+ return spi_nor_check_op(nor, &op);
+}
+
+/**
+ * spi_nor_adjust_hwcaps - Find optimal Read/Write protocol based on SPI
+ * controller capabilities
+ * @nor: pointer to a 'struct spi_nor'
+ * @params: pointer to the 'struct spi_nor_flash_parameter'
+ * representing SPI NOR flash capabilities
+ * @hwcaps: pointer to resulting capabilities after adjusting
+ * according to controller and flash's capability
+ */
+static void
+spi_nor_adjust_hwcaps(struct spi_nor *nor,
+ const struct spi_nor_flash_parameter *params,
+ u32 *hwcaps)
+{
+ unsigned int cap;
+
+ /* DTR modes are not supported yet, mask them all. */
+ *hwcaps &= ~SNOR_HWCAPS_DTR;
+
+ /* X-X-X modes are not supported yet, mask them all. */
+ *hwcaps &= ~SNOR_HWCAPS_X_X_X;
+
+ for (cap = 0; cap < sizeof(*hwcaps) * BITS_PER_BYTE; cap++) {
+ int rdidx, ppidx;
+
+ if (!(*hwcaps & BIT(cap)))
+ continue;
+
+ rdidx = spi_nor_hwcaps_read2cmd(BIT(cap));
+ if (rdidx >= 0 &&
+ spi_nor_check_readop(nor, ¶ms->reads[rdidx]))
+ *hwcaps &= ~BIT(cap);
+
+ ppidx = spi_nor_hwcaps_pp2cmd(BIT(cap));
+ if (ppidx < 0)
+ continue;
+
+ if (spi_nor_check_pp(nor, ¶ms->page_programs[ppidx]))
+ *hwcaps &= ~BIT(cap);
+ }
+}
+
static int spi_nor_select_read(struct spi_nor *nor,
const struct spi_nor_flash_parameter *params,
u32 shared_hwcaps)
@@ -2372,7 +2490,7 @@ static int spi_nor_default_setup(struct spi_nor *nor,
const struct spi_nor_flash_parameter *params,
const struct spi_nor_hwcaps *hwcaps)
{
- u32 ignored_mask, shared_mask;
+ u32 shared_mask;
bool enable_quad_io;
int err;
@@ -2382,17 +2500,12 @@ static int spi_nor_default_setup(struct spi_nor *nor,
*/
shared_mask = hwcaps->mask & params->hwcaps.mask;
- /* SPI n-n-n protocols are not supported yet. */
- ignored_mask = (SNOR_HWCAPS_READ_2_2_2 |
- SNOR_HWCAPS_READ_4_4_4 |
- SNOR_HWCAPS_READ_8_8_8 |
- SNOR_HWCAPS_PP_4_4_4 |
- SNOR_HWCAPS_PP_8_8_8);
- if (shared_mask & ignored_mask) {
- dev_dbg(nor->dev,
- "SPI n-n-n protocols are not supported yet.\n");
- shared_mask &= ~ignored_mask;
- }
+ /*
+ * When called from spi_nor_probe(), all caps are set and we need to
+ * discard some of them based on what the SPI controller actually
+ * supports (using spi_mem_supports_op()).
+ */
+ spi_nor_adjust_hwcaps(nor, params, &shared_mask);
/* Select the (Fast) Read command. */
err = spi_nor_select_read(nor, params, shared_mask);
@@ -2487,12 +2600,12 @@ int spi_nor_scan(struct spi_nor *nor)
struct spi_nor_flash_parameter params;
const struct flash_info *info = NULL;
struct mtd_info *mtd = &nor->mtd;
- struct spi_nor_hwcaps hwcaps = {
- .mask = SNOR_HWCAPS_READ |
- SNOR_HWCAPS_READ_FAST |
- SNOR_HWCAPS_PP,
- };
struct spi_slave *spi = nor->spi;
+ /*
+ * Enable all caps by default. The core will mask them after
+ * checking what's really supported using spi_mem_supports_op().
+ */
+ const struct spi_nor_hwcaps hwcaps = { .mask = SNOR_HWCAPS_ALL };
int ret;
/* Reset SPI protocol for all commands. */
@@ -2506,27 +2619,6 @@ int spi_nor_scan(struct spi_nor *nor)
nor->setup = spi_nor_default_setup;
- if (spi->mode & SPI_RX_OCTAL) {
- hwcaps.mask |= SNOR_HWCAPS_READ_1_1_8;
-
- if (spi->mode & SPI_TX_OCTAL)
- hwcaps.mask |= (SNOR_HWCAPS_READ_1_8_8 |
- SNOR_HWCAPS_PP_1_1_8 |
- SNOR_HWCAPS_PP_1_8_8);
- } else if (spi->mode & SPI_RX_QUAD) {
- hwcaps.mask |= SNOR_HWCAPS_READ_1_1_4;
-
- if (spi->mode & SPI_TX_QUAD)
- hwcaps.mask |= (SNOR_HWCAPS_READ_1_4_4 |
- SNOR_HWCAPS_PP_1_1_4 |
- SNOR_HWCAPS_PP_1_4_4);
- } else if (spi->mode & SPI_RX_DUAL) {
- hwcaps.mask |= SNOR_HWCAPS_READ_1_1_2;
-
- if (spi->mode & SPI_TX_DUAL)
- hwcaps.mask |= SNOR_HWCAPS_READ_1_2_2;
- }
-
info = spi_nor_read_id(nor);
if (IS_ERR_OR_NULL(info))
return -ENOENT;
diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h
index 922e795ea6..327491fb17 100644
--- a/include/linux/mtd/spi-nor.h
+++ b/include/linux/mtd/spi-nor.h
@@ -312,6 +312,20 @@ struct spi_nor_hwcaps {
#define SNOR_HWCAPS_PP_1_8_8 BIT(21)
#define SNOR_HWCAPS_PP_8_8_8 BIT(22)
+#define SNOR_HWCAPS_X_X_X (SNOR_HWCAPS_READ_2_2_2 | \
+ SNOR_HWCAPS_READ_4_4_4 | \
+ SNOR_HWCAPS_READ_8_8_8 | \
+ SNOR_HWCAPS_PP_4_4_4 | \
+ SNOR_HWCAPS_PP_8_8_8)
+
+#define SNOR_HWCAPS_DTR (SNOR_HWCAPS_READ_1_1_1_DTR | \
+ SNOR_HWCAPS_READ_1_2_2_DTR | \
+ SNOR_HWCAPS_READ_1_4_4_DTR | \
+ SNOR_HWCAPS_READ_1_8_8_DTR)
+
+#define SNOR_HWCAPS_ALL (SNOR_HWCAPS_READ_MASK | \
+ SNOR_HWCAPS_PP_MASK)
+
struct spi_nor_read_command {
u8 num_mode_clocks;
u8 num_wait_states;
--
2.26.2
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