spi: spi-ti-qspi: Support per spi-mem operation frequency switches

Every ->exec_op() call correctly configures the spi bus speed to the
maximum allowed frequency for the memory using the constant spi default
parameter. Since we can now have per-operation constraints, let's use
the value that comes from the spi-mem operation structure instead. In
case there is no specific limitation for this operation, the default spi
device value will be given anyway.

The per-operation frequency capability is thus advertised to the spi-mem
core.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://patch.msgid.link/20241224-winbond-6-11-rc1-quad-support-v2-15-ad218dbc406f@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi-ti-qspi.c

@@ -623,7 +623,7 @@ static int ti_qspi_exec_mem_op(struct spi_mem *mem,
 	mutex_lock(&qspi->list_lock);
 
 	if (!qspi->mmap_enabled || qspi->current_cs != spi_get_chipselect(mem->spi, 0)) {
-		ti_qspi_setup_clk(qspi, mem->spi->max_speed_hz);
+		ti_qspi_setup_clk(qspi, op->max_freq);
 		ti_qspi_enable_memory_map(mem->spi);
 	}
 	ti_qspi_setup_mmap_read(mem->spi, op->cmd.opcode, op->data.buswidth,
@@ -658,6 +658,10 @@ static const struct spi_controller_mem_ops ti_qspi_mem_ops = {
 	.adjust_op_size = ti_qspi_adjust_op_size,
 };
 
+static const struct spi_controller_mem_caps ti_qspi_mem_caps = {
+	.per_op_freq = true,
+};
+
 static int ti_qspi_start_transfer_one(struct spi_controller *host,
 		struct spi_message *m)
 {
@@ -777,6 +781,7 @@ static int ti_qspi_probe(struct platform_device *pdev)
 	host->bits_per_word_mask = SPI_BPW_MASK(32) | SPI_BPW_MASK(16) |
 				   SPI_BPW_MASK(8);
 	host->mem_ops = &ti_qspi_mem_ops;
+	host->mem_caps = &ti_qspi_mem_caps;
 
 	if (!of_property_read_u32(np, "num-cs", &num_cs))
 		host->num_chipselect = num_cs;