[PATCH v12 15/38] spi: ep93xx: add DT support for Cirrus EP93xx

Nikita Shubin via B4 Relay
2024-09-09T08:12:16Z

- add OF ID match table
- add device tree DMA request, so we can probe defer, in case DMA is not
ready yet
- drop DMA platform code

Signed-off-by: Nikita Shubin <nikita.shubin@maquefel.me>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Alexander Sverdlin <alexander.sverdlin@gmail.com>
Acked-by: Alexander Sverdlin <alexander.sverdlin@gmail.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
---
drivers/spi/spi-ep93xx.c | 66 +++++++++++++++++-------------------------------
1 file changed, 23 insertions(+), 43 deletions(-)

diff --git a/drivers/spi/spi-ep93xx.c b/drivers/spi/spi-ep93xx.c
index a1d60e51c053..ffbe0d522bce 100644
--- a/drivers/spi/spi-ep93xx.c
+++ b/drivers/spi/spi-ep93xx.c
@@ -18,18 +18,18 @@
#include <linux/err.h>
#include <linux/delay.h>
#include <linux/device.h>
+#include <linux/dma-direction.h>
+#include <linux/dma-mapping.h>
#include <linux/dmaengine.h>
#include <linux/bitops.h>
#include <linux/interrupt.h>
#include <linux/module.h>
+#include <linux/property.h>
#include <linux/platform_device.h>
#include <linux/sched.h>
#include <linux/scatterlist.h>
#include <linux/spi/spi.h>

-#include <linux/platform_data/dma-ep93xx.h>
-#include <linux/platform_data/spi-ep93xx.h>
-
#define SSPCR0 0x0000
#define SSPCR0_SPO BIT(6)
#define SSPCR0_SPH BIT(7)
@@ -92,8 +92,6 @@ struct ep93xx_spi {
size_t fifo_level;
struct dma_chan *dma_rx;
struct dma_chan *dma_tx;
- struct ep93xx_dma_data dma_rx_data;
- struct ep93xx_dma_data dma_tx_data;
struct sg_table rx_sgt;
struct sg_table tx_sgt;
void *zeropage;
@@ -575,46 +573,23 @@ static int ep93xx_spi_unprepare_hardware(struct spi_controller *host)
return 0;
}

-static bool ep93xx_spi_dma_filter(struct dma_chan *chan, void *filter_param)
+static int ep93xx_spi_setup_dma(struct device *dev, struct ep93xx_spi *espi)
{
- if (ep93xx_dma_chan_is_m2p(chan))
- return false;
-
- chan->private = filter_param;
- return true;
-}
-
-static int ep93xx_spi_setup_dma(struct ep93xx_spi *espi)
-{
- dma_cap_mask_t mask;
int ret;

espi->zeropage = (void *)get_zeroed_page(GFP_KERNEL);
if (!espi->zeropage)
return -ENOMEM;

- dma_cap_zero(mask);
- dma_cap_set(DMA_SLAVE, mask);
-
- espi->dma_rx_data.port = EP93XX_DMA_SSP;
- espi->dma_rx_data.direction = DMA_DEV_TO_MEM;
- espi->dma_rx_data.name = "ep93xx-spi-rx";
-
- espi->dma_rx = dma_request_channel(mask, ep93xx_spi_dma_filter,
- &espi->dma_rx_data);
- if (!espi->dma_rx) {
- ret = -ENODEV;
+ espi->dma_rx = dma_request_chan(dev, "rx");
+ if (IS_ERR(espi->dma_rx)) {
+ ret = dev_err_probe(dev, PTR_ERR(espi->dma_rx), "rx DMA setup failed");
goto fail_free_page;
}

- espi->dma_tx_data.port = EP93XX_DMA_SSP;
- espi->dma_tx_data.direction = DMA_MEM_TO_DEV;
- espi->dma_tx_data.name = "ep93xx-spi-tx";
-
- espi->dma_tx = dma_request_channel(mask, ep93xx_spi_dma_filter,
- &espi->dma_tx_data);
- if (!espi->dma_tx) {
- ret = -ENODEV;
+ espi->dma_tx = dma_request_chan(dev, "tx");
+ if (IS_ERR(espi->dma_tx)) {
+ ret = dev_err_probe(dev, PTR_ERR(espi->dma_tx), "tx DMA setup failed");
goto fail_release_rx;
}

@@ -647,18 +622,11 @@ static void ep93xx_spi_release_dma(struct ep93xx_spi *espi)
static int ep93xx_spi_probe(struct platform_device *pdev)
{
struct spi_controller *host;
- struct ep93xx_spi_info *info;
struct ep93xx_spi *espi;
struct resource *res;
int irq;
int error;

- info = dev_get_platdata(&pdev->dev);
- if (!info) {
- dev_err(&pdev->dev, "missing platform data\n");
- return -EINVAL;
- }
-
irq = platform_get_irq(pdev, 0);
if (irq < 0)
return irq;
@@ -713,12 +681,17 @@ static int ep93xx_spi_probe(struct platform_device *pdev)
goto fail_release_host;
}

- if (info->use_dma && ep93xx_spi_setup_dma(espi))
+ error = ep93xx_spi_setup_dma(&pdev->dev, espi);
+ if (error == -EPROBE_DEFER)
+ goto fail_release_host;
+
+ if (error)
dev_warn(&pdev->dev, "DMA setup failed. Falling back to PIO\n");

/* make sure that the hardware is disabled */
writel(0, espi->mmio + SSPCR1);

+ device_set_node(&host->dev, dev_fwnode(&pdev->dev));
error = devm_spi_register_controller(&pdev->dev, host);
if (error) {
dev_err(&pdev->dev, "failed to register SPI host\n");
@@ -746,9 +719,16 @@ static void ep93xx_spi_remove(struct platform_device *pdev)
ep93xx_spi_release_dma(espi);
}

+static const struct of_device_id ep93xx_spi_of_ids[] = {
+ { .compatible = "cirrus,ep9301-spi" },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, ep93xx_spi_of_ids);
+
static struct platform_driver ep93xx_spi_driver = {
.driver = {
.name = "ep93xx-spi",
+ .of_match_table = ep93xx_spi_of_ids,
},
.probe = ep93xx_spi_probe,
.remove_new = ep93xx_spi_remove,

--
2.43.2