[PATCH v2 03/11] spi: spi-mem: allow specifying whether an op is DTR or not

Pratyush Yadav
2020-02-26T09:37:47Z

Each phase is given a separate 'is_dtr' field so mixed protocols like
4S-4D-4D can be supported.

Also add the mode bits SPI_RX_DTR and SPI_TX_DTR so controllers can
specify whether they support DTR modes or not.

Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
---
drivers/spi/spi-mem.c | 23 +++++++++++++++++++++++
include/linux/spi/spi-mem.h | 8 ++++++++
2 files changed, 31 insertions(+)

diff --git a/drivers/spi/spi-mem.c b/drivers/spi/spi-mem.c
index e5a46f0eb93b..cb13e0878b95 100644
--- a/drivers/spi/spi-mem.c
+++ b/drivers/spi/spi-mem.c
@@ -99,6 +99,16 @@ void spi_controller_dma_unmap_mem_op_data(struct spi_controller *ctlr,
}
EXPORT_SYMBOL_GPL(spi_controller_dma_unmap_mem_op_data);

+static int spi_check_dtr_req(struct spi_mem *mem, bool tx)
+{
+ u32 mode = mem->spi->mode;
+
+ if ((tx && (mode & SPI_TX_DTR)) || (!tx && (mode & SPI_RX_DTR)))
+ return 0;
+
+ return -ENOTSUPP;
+}
+
static int spi_check_buswidth_req(struct spi_mem *mem, u8 buswidth, bool tx)
{
u32 mode = mem->spi->mode;
@@ -154,6 +164,19 @@ bool spi_mem_default_supports_op(struct spi_mem *mem,
op->data.dir == SPI_MEM_DATA_OUT))
return false;

+ if (op->cmd.is_dtr && spi_check_dtr_req(mem, true))
+ return false;
+
+ if (op->addr.is_dtr && spi_check_dtr_req(mem, true))
+ return false;
+
+ if (op->dummy.is_dtr && spi_check_dtr_req(mem, true))
+ return false;
+
+ if (op->data.dir != SPI_MEM_NO_DATA && op->data.is_dtr &&
+ spi_check_dtr_req(mem, op->data.dir == SPI_MEM_DATA_OUT))
+ return false;
+
return true;
}
EXPORT_SYMBOL_GPL(spi_mem_default_supports_op);
diff --git a/include/linux/spi/spi-mem.h b/include/linux/spi/spi-mem.h
index af9ff2f0f1b2..4669082b4e3b 100644
--- a/include/linux/spi/spi-mem.h
+++ b/include/linux/spi/spi-mem.h
@@ -71,6 +71,7 @@ enum spi_mem_data_dir {
* struct spi_mem_op - describes a SPI memory operation
* @cmd.buswidth: number of IO lines used to transmit the command
* @cmd.opcode: operation opcode
+ * @cmd.is_dtr: whether the command opcode should be sent in DTR mode or not
* @addr.nbytes: number of address bytes to send. Can be zero if the operation
* does not need to send an address
* @addr.buswidth: number of IO lines used to transmit the address cycles
@@ -78,10 +79,13 @@ enum spi_mem_data_dir {
* Note that only @addr.nbytes are taken into account in this
* address value, so users should make sure the value fits in the
* assigned number of bytes.
+ * @addr.is_dtr: whether the address should be sent in DTR mode or not
* @dummy.nbytes: number of dummy bytes to send after an opcode or address. Can
* be zero if the operation does not require dummy bytes
* @dummy.buswidth: number of IO lanes used to transmit the dummy bytes
+ * @dummy.is_dtr: whether the dummy bytes should be sent in DTR mode or not
* @data.buswidth: number of IO lanes used to send/receive the data
+ * @data.is_dtr: whether the data should be sent in DTR mode or not
* @data.dir: direction of the transfer
* @data.nbytes: number of data bytes to send/receive. Can be zero if the
* operation does not involve transferring data
@@ -92,21 +96,25 @@ struct spi_mem_op {
struct {
u8 buswidth;
u8 opcode;
+ bool is_dtr;
} cmd;

struct {
u8 nbytes;
u8 buswidth;
u64 val;
+ bool is_dtr;
} addr;

struct {
u8 nbytes;
u8 buswidth;
+ bool is_dtr;
} dummy;

struct {
u8 buswidth;
+ bool is_dtr;
enum spi_mem_data_dir dir;
unsigned int nbytes;
union {
--
2.25.0