spi: rockchip-sfc: 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>
Cc: Haibo Chen <haibo.chen@nxp.com>
Cc: Yogesh Gaur <yogeshgaur.83@gmail.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://patch.msgid.link/20241224-winbond-6-11-rc1-quad-support-v2-13-ad218dbc406f@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi-rockchip-sfc.c

@@ -492,11 +492,11 @@ static int rockchip_sfc_exec_mem_op(struct spi_mem *mem, const struct spi_mem_op
 	u32 len = op->data.nbytes;
 	int ret;
 
-	if (unlikely(mem->spi->max_speed_hz != sfc->frequency)) {
-		ret = clk_set_rate(sfc->clk, mem->spi->max_speed_hz);
+	if (unlikely(op->max_freq != sfc->frequency)) {
+		ret = clk_set_rate(sfc->clk, op->max_freq);
 		if (ret)
 			return ret;
-		sfc->frequency = mem->spi->max_speed_hz;
+		sfc->frequency = op->max_freq;
 		dev_dbg(sfc->dev, "set_freq=%dHz real_freq=%ldHz\n",
 			sfc->frequency, clk_get_rate(sfc->clk));
 	}
@@ -536,6 +536,10 @@ static const struct spi_controller_mem_ops rockchip_sfc_mem_ops = {
 	.adjust_op_size = rockchip_sfc_adjust_op_size,
 };
 
+static const struct spi_controller_mem_caps rockchip_sfc_mem_caps = {
+	.per_op_freq = true,
+};
+
 static irqreturn_t rockchip_sfc_irq_handler(int irq, void *dev_id)
 {
 	struct rockchip_sfc *sfc = dev_id;
@@ -568,6 +572,7 @@ static int rockchip_sfc_probe(struct platform_device *pdev)
 
 	host->flags = SPI_CONTROLLER_HALF_DUPLEX;
 	host->mem_ops = &rockchip_sfc_mem_ops;
+	host->mem_caps = &rockchip_sfc_mem_caps;
 	host->dev.of_node = pdev->dev.of_node;
 	host->mode_bits = SPI_TX_QUAD | SPI_TX_DUAL | SPI_RX_QUAD | SPI_RX_DUAL;
 	host->max_speed_hz = SFC_MAX_SPEED;