[PATCH v6 09/21] mtd: spi-nor-core: Rework hwcaps selection
Pratyush Yadav
p.yadav at ti.com
Fri Jun 5 14:44:48 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().
To make sure the build doesn't break for boards not using CONFIG_DM_SPI,
add a simple SPI_{RX,TX}_ based hwcaps selection logic in spi-mem-nodm
similar to spi_mem_default_supports_op(). This change is only
compile-tested.
To avoid SPL size problems on the x530 board, the old hwcaps selection
is still kept around. Leaving the code in-place was getting difficult to
read and understand, so the code is restructured to have it all in one
isolated function. As a result of this, the parameter hwcaps to
spi_nor_setup() is no longer needed. Remove it.
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/Kconfig | 9 ++
drivers/mtd/spi/spi-nor-core.c | 244 ++++++++++++++++++++++++++-------
drivers/spi/spi-mem-nodm.c | 62 +++++++++
include/linux/mtd/spi-nor.h | 17 ++-
4 files changed, 280 insertions(+), 52 deletions(-)
diff --git a/drivers/mtd/spi/Kconfig b/drivers/mtd/spi/Kconfig
index 018e8c597e..09ec18cdf2 100644
--- a/drivers/mtd/spi/Kconfig
+++ b/drivers/mtd/spi/Kconfig
@@ -88,6 +88,15 @@ config SPI_FLASH_SFDP_SUPPORT
SPI NOR flashes using Serial Flash Discoverable Parameters (SFDP)
tables as per JESD216 standard.
+config SPI_FLASH_SMART_HWCAPS
+ bool "Smart hardware capability detection based on SPI MEM supports_op() hook"
+ default y
+ help
+ Enable support for smart hardware capability detection based on SPI
+ MEM supports_op() hook that lets controllers express whether they
+ can support a type of operation in a much more refined way compared
+ to using flags like SPI_RX_DUAL, SPI_TX_QUAD, etc.
+
config SPI_FLASH_BAR
bool "SPI flash Bank/Extended address register support"
help
diff --git a/drivers/mtd/spi/spi-nor-core.c b/drivers/mtd/spi/spi-nor-core.c
index 2494c2e724..a50575ca8b 100644
--- a/drivers/mtd/spi/spi-nor-core.c
+++ b/drivers/mtd/spi/spi-nor-core.c
@@ -2294,6 +2294,194 @@ static int spi_nor_hwcaps_pp2cmd(u32 hwcaps)
ARRAY_SIZE(hwcaps_pp2cmd));
}
+#ifdef CONFIG_SPI_FLASH_SMART_HWCAPS
+/**
+ * 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
+ *
+ * Discard caps based on what the SPI controller actually supports (using
+ * spi_mem_supports_op()).
+ */
+static void
+spi_nor_adjust_hwcaps(struct spi_nor *nor,
+ const struct spi_nor_flash_parameter *params,
+ u32 *hwcaps)
+{
+ unsigned int cap;
+
+ /*
+ * Enable all caps by default. We will mask them after checking what's
+ * really supported using spi_mem_supports_op().
+ */
+ *hwcaps = SNOR_HWCAPS_ALL;
+
+ /* 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);
+ }
+}
+#else
+/**
+ * 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
+ *
+ * Select caps based on what the SPI controller and SPI flash both support.
+ */
+static void
+spi_nor_adjust_hwcaps(struct spi_nor *nor,
+ const struct spi_nor_flash_parameter *params,
+ u32 *hwcaps)
+{
+ struct spi_slave *spi = nor->spi;
+ u32 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);
+ u32 spi_hwcaps = (SNOR_HWCAPS_READ | SNOR_HWCAPS_READ_FAST |
+ SNOR_HWCAPS_PP);
+
+ /* Get the hardware capabilities the SPI controller supports. */
+ if (spi->mode & SPI_RX_OCTAL) {
+ spi_hwcaps |= SNOR_HWCAPS_READ_1_1_8;
+
+ if (spi->mode & SPI_TX_OCTAL)
+ spi_hwcaps |= (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) {
+ spi_hwcaps |= SNOR_HWCAPS_READ_1_1_4;
+
+ if (spi->mode & SPI_TX_QUAD)
+ spi_hwcaps |= (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) {
+ spi_hwcaps |= SNOR_HWCAPS_READ_1_1_2;
+
+ if (spi->mode & SPI_TX_DUAL)
+ spi_hwcaps |= SNOR_HWCAPS_READ_1_2_2;
+ }
+
+ /*
+ * Keep only the hardware capabilities supported by both the SPI
+ * controller and the SPI flash memory.
+ */
+ *hwcaps = spi_hwcaps & params->hwcaps.mask;
+ if (*hwcaps & ignored_mask) {
+ dev_dbg(nor->dev,
+ "SPI n-n-n protocols are not supported yet.\n");
+ *hwcaps &= ~ignored_mask;
+ }
+}
+#endif /* CONFIG_SPI_FLASH_SMART_HWCAPS */
+
static int spi_nor_select_read(struct spi_nor *nor,
const struct spi_nor_flash_parameter *params,
u32 shared_hwcaps)
@@ -2374,30 +2562,13 @@ static int spi_nor_select_erase(struct spi_nor *nor,
static int spi_nor_default_setup(struct spi_nor *nor,
const struct flash_info *info,
- const struct spi_nor_flash_parameter *params,
- const struct spi_nor_hwcaps *hwcaps)
+ const struct spi_nor_flash_parameter *params)
{
- u32 ignored_mask, shared_mask;
+ u32 shared_mask;
bool enable_quad_io;
int err;
- /*
- * Keep only the hardware capabilities supported by both the SPI
- * controller and the SPI flash memory.
- */
- 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;
- }
+ spi_nor_adjust_hwcaps(nor, params, &shared_mask);
/* Select the (Fast) Read command. */
err = spi_nor_select_read(nor, params, shared_mask);
@@ -2435,13 +2606,12 @@ static int spi_nor_default_setup(struct spi_nor *nor,
}
static int spi_nor_setup(struct spi_nor *nor, const struct flash_info *info,
- const struct spi_nor_flash_parameter *params,
- const struct spi_nor_hwcaps *hwcaps)
+ const struct spi_nor_flash_parameter *params)
{
if (!nor->setup)
return 0;
- return nor->setup(nor, info, params, hwcaps);
+ return nor->setup(nor, info, params);
}
static int spi_nor_init(struct spi_nor *nor)
@@ -2496,11 +2666,6 @@ 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;
int ret;
@@ -2515,27 +2680,6 @@ 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;
@@ -2609,7 +2753,7 @@ int spi_nor_scan(struct spi_nor *nor)
* - set the SPI protocols for register and memory accesses.
* - set the Quad Enable bit if needed (required by SPI x-y-4 protos).
*/
- ret = spi_nor_setup(nor, info, ¶ms, &hwcaps);
+ ret = spi_nor_setup(nor, info, ¶ms);
if (ret)
return ret;
diff --git a/drivers/spi/spi-mem-nodm.c b/drivers/spi/spi-mem-nodm.c
index db54101383..050d25040c 100644
--- a/drivers/spi/spi-mem-nodm.c
+++ b/drivers/spi/spi-mem-nodm.c
@@ -105,3 +105,65 @@ int spi_mem_adjust_op_size(struct spi_slave *slave,
return 0;
}
+
+static int spi_check_buswidth_req(struct spi_slave *slave, u8 buswidth, bool tx)
+{
+ u32 mode = slave->mode;
+
+ switch (buswidth) {
+ case 1:
+ return 0;
+
+ case 2:
+ if ((tx && (mode & (SPI_TX_DUAL | SPI_TX_QUAD))) ||
+ (!tx && (mode & (SPI_RX_DUAL | SPI_RX_QUAD))))
+ return 0;
+
+ break;
+
+ case 4:
+ if ((tx && (mode & SPI_TX_QUAD)) ||
+ (!tx && (mode & SPI_RX_QUAD)))
+ return 0;
+
+ break;
+ case 8:
+ if ((tx && (mode & SPI_TX_OCTAL)) ||
+ (!tx && (mode & SPI_RX_OCTAL)))
+ return 0;
+
+ break;
+
+ default:
+ break;
+ }
+
+ return -ENOTSUPP;
+}
+
+bool spi_mem_supports_op(struct spi_slave *slave, const struct spi_mem_op *op)
+{
+ if (spi_check_buswidth_req(slave, op->cmd.buswidth, true))
+ return false;
+
+ if (op->addr.nbytes &&
+ spi_check_buswidth_req(slave, op->addr.buswidth, true))
+ return false;
+
+ if (op->dummy.nbytes &&
+ spi_check_buswidth_req(slave, op->dummy.buswidth, true))
+ return false;
+
+ if (op->data.dir != SPI_MEM_NO_DATA &&
+ spi_check_buswidth_req(slave, op->data.buswidth,
+ op->data.dir == SPI_MEM_DATA_OUT))
+ return false;
+
+ if (op->cmd.dtr || op->addr.dtr || op->dummy.dtr || op->data.dtr)
+ return false;
+
+ if (op->cmd.nbytes != 1)
+ return false;
+
+ return true;
+}
diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h
index 5842e9d6ee..cca7919fdd 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;
@@ -459,8 +473,7 @@ struct spi_nor {
struct spi_nor_fixups *fixups;
int (*setup)(struct spi_nor *nor, const struct flash_info *info,
- const struct spi_nor_flash_parameter *params,
- const struct spi_nor_hwcaps *hwcaps);
+ const struct spi_nor_flash_parameter *params);
int (*prepare)(struct spi_nor *nor, enum spi_nor_ops ops);
void (*unprepare)(struct spi_nor *nor, enum spi_nor_ops ops);
int (*read_reg)(struct spi_nor *nor, u8 opcode, u8 *buf, int len);
--
2.27.0
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