spi: amd: 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.

This controller however performed a frequency check, which is also
observed during the ->check_op() phase.

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

Cc: Sanjay R Mehta <sanju.mehta@amd.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://patch.msgid.link/20241224-winbond-6-11-rc1-quad-support-v2-3-ad218dbc406f@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>

Author: miquelraynal

drivers/spi/spi-amd.c

@@ -479,6 +479,9 @@ static bool amd_spi_supports_op(struct spi_mem *mem,
 		return false;
 	}
 
+	if (op->max_freq < mem->spi->controller->min_speed_hz)
+		return false;
+
 	return spi_mem_default_supports_op(mem, op);
 }
 
@@ -676,7 +679,7 @@ static int amd_spi_exec_mem_op(struct spi_mem *mem,
 
 	amd_spi = spi_controller_get_devdata(mem->spi->controller);
 
-	ret = amd_set_spi_freq(amd_spi, mem->spi->max_speed_hz);
+	ret = amd_set_spi_freq(amd_spi, op->max_freq);
 	if (ret)
 		return ret;
 
@@ -705,6 +708,10 @@ static const struct spi_controller_mem_ops amd_spi_mem_ops = {
 	.supports_op = amd_spi_supports_op,
 };
 
+static const struct spi_controller_mem_caps amd_spi_mem_caps = {
+	.per_op_freq = true,
+};
+
 static int amd_spi_host_transfer(struct spi_controller *host,
 				   struct spi_message *msg)
 {
@@ -782,6 +789,7 @@ static int amd_spi_probe(struct platform_device *pdev)
 	host->setup = amd_spi_host_setup;
 	host->transfer_one_message = amd_spi_host_transfer;
 	host->mem_ops = &amd_spi_mem_ops;
+	host->mem_caps = &amd_spi_mem_caps;
 	host->max_transfer_size = amd_spi_max_transfer_size;
 	host->max_message_size = amd_spi_max_transfer_size;