spi: rspi: Fill in controller speed limits

Fill in the controller speed limits, so the SPI core can use them for
validating SPI transfers, and adjusting them where needed.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20200819125904.20938-8-geert+renesas@glider.be
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/spi/spi-rspi.c b/drivers/spi/spi-rspi.c
index 2b5334e..e39fd38 100644 (file)
--- a/drivers/spi/spi-rspi.c
+++ b/drivers/spi/spi-rspi.c
@@ -243,6 +243,8 @@ struct spi_ops {
        int (*transfer_one)(struct spi_controller *ctlr,
                            struct spi_device *spi, struct spi_transfer *xfer);
        u16 extra_mode_bits;
+       u16 min_div;
+       u16 max_div;
        u16 flags;
        u16 fifo_size;
        u8 num_hw_ss;
@@ -1181,6 +1183,8 @@ static int rspi_remove(struct platform_device *pdev)
 static const struct spi_ops rspi_ops = {
        .set_config_register =  rspi_set_config_register,
        .transfer_one =         rspi_transfer_one,
+       .min_div =              2,
+       .max_div =              4096,
        .flags =                SPI_CONTROLLER_MUST_TX,
        .fifo_size =            8,
        .num_hw_ss =            2,
@@ -1189,6 +1193,8 @@ static const struct spi_ops rspi_ops = {
 static const struct spi_ops rspi_rz_ops = {
        .set_config_register =  rspi_rz_set_config_register,
        .transfer_one =         rspi_rz_transfer_one,
+       .min_div =              2,
+       .max_div =              4096,
        .flags =                SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX,
        .fifo_size =            8,      /* 8 for TX, 32 for RX */
        .num_hw_ss =            1,
@@ -1199,6 +1205,8 @@ static const struct spi_ops qspi_ops = {
        .transfer_one =         qspi_transfer_one,
        .extra_mode_bits =      SPI_TX_DUAL | SPI_TX_QUAD |
                                SPI_RX_DUAL | SPI_RX_QUAD,
+       .min_div =              1,
+       .max_div =              4080,
        .flags =                SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX,
        .fifo_size =            32,
        .num_hw_ss =            1,
@@ -1260,6 +1268,7 @@ static int rspi_probe(struct platform_device *pdev)
        int ret;
        const struct rspi_plat_data *rspi_pd;
        const struct spi_ops *ops;
+       unsigned long clksrc;
 
        ctlr = spi_alloc_master(&pdev->dev, sizeof(struct rspi_data));
        if (ctlr == NULL)
@@ -1312,6 +1321,9 @@ static int rspi_probe(struct platform_device *pdev)
        ctlr->unprepare_message = rspi_unprepare_message;
        ctlr->mode_bits = SPI_CPHA | SPI_CPOL | SPI_CS_HIGH | SPI_LSB_FIRST |
                          SPI_LOOP | ops->extra_mode_bits;
+       clksrc = clk_get_rate(rspi->clk);
+       ctlr->min_speed_hz = DIV_ROUND_UP(clksrc, ops->max_div);
+       ctlr->max_speed_hz = DIV_ROUND_UP(clksrc, ops->min_div);
        ctlr->flags = ops->flags;
        ctlr->dev.of_node = pdev->dev.of_node;
        ctlr->use_gpio_descriptors = true;