spi: fsl-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.

Cc: Han Xu <han.xu@nxp.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://patch.msgid.link/20241224-winbond-6-11-rc1-quad-support-v2-8-ad218dbc406f@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi-fsl-qspi.c

@@ -522,9 +522,10 @@ static void fsl_qspi_invalidate(struct fsl_qspi *q)
 	qspi_writel(q, reg, q->iobase + QUADSPI_MCR);
 }
 
-static void fsl_qspi_select_mem(struct fsl_qspi *q, struct spi_device *spi)
+static void fsl_qspi_select_mem(struct fsl_qspi *q, struct spi_device *spi,
+				const struct spi_mem_op *op)
 {
-	unsigned long rate = spi->max_speed_hz;
+	unsigned long rate = op->max_freq;
 	int ret;
 
 	if (q->selected == spi_get_chipselect(spi, 0))
@@ -652,7 +653,7 @@ static int fsl_qspi_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
 	fsl_qspi_readl_poll_tout(q, base + QUADSPI_SR, (QUADSPI_SR_IP_ACC_MASK |
 				 QUADSPI_SR_AHB_ACC_MASK), 10, 1000);
 
-	fsl_qspi_select_mem(q, mem->spi);
+	fsl_qspi_select_mem(q, mem->spi, op);
 
 	if (needs_amba_base_offset(q))
 		addr_offset = q->memmap_phy;
@@ -839,6 +840,10 @@ static const struct spi_controller_mem_ops fsl_qspi_mem_ops = {
 	.get_name = fsl_qspi_get_name,
 };
 
+static const struct spi_controller_mem_caps fsl_qspi_mem_caps = {
+	.per_op_freq = true,
+};
+
 static int fsl_qspi_probe(struct platform_device *pdev)
 {
 	struct spi_controller *ctlr;
@@ -923,6 +928,7 @@ static int fsl_qspi_probe(struct platform_device *pdev)
 	ctlr->bus_num = -1;
 	ctlr->num_chipselect = 4;
 	ctlr->mem_ops = &fsl_qspi_mem_ops;
+	ctlr->mem_caps = &fsl_qspi_mem_caps;
 
 	fsl_qspi_default_setup(q);