[PATCH v3 3/7] spi: spi-ep93xx: add spi master prepare_transfer_hardware()

From: Chris Packham
Date: Tue Aug 08 2017 - 16:51:44 EST


From: H Hartley Sweeten <hsweeten@xxxxxxxxxxxxxxxxxxx>

This driver currently enables the hardware at the start of every
message and disabled it when the message is complete. Make it a
bit smarter by adding the prepare_transfer_hardware() and
unprepare_transfer_hardware() callbacks so that the core can
enable/disable the hardware based on spi message queue.

Signed-off-by: H Hartley Sweeten <hsweeten@xxxxxxxxxxxxxxxxxxx>
[chris: use u32 instead of unsigned int]
Signed-off-by: Chris Packham <chris.packham@xxxxxxxxxxxxxxxxxxx>
Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
---
drivers/spi/spi-ep93xx.c | 72 ++++++++++++++++++++++--------------------------
1 file changed, 33 insertions(+), 39 deletions(-)

diff --git a/drivers/spi/spi-ep93xx.c b/drivers/spi/spi-ep93xx.c
index 0bd792020471..ce6ec164f2f2 100644
--- a/drivers/spi/spi-ep93xx.c
+++ b/drivers/spi/spi-ep93xx.c
@@ -111,33 +111,6 @@ struct ep93xx_spi {
/* converts bits per word to CR0.DSS value */
#define bits_per_word_to_dss(bpw) ((bpw) - 1)

-static int ep93xx_spi_enable(const struct ep93xx_spi *espi)
-{
- u32 val;
- int err;
-
- err = clk_enable(espi->clk);
- if (err)
- return err;
-
- val = readl(espi->mmio + SSPCR1);
- val |= SSPCR1_SSE;
- writel(val, espi->mmio + SSPCR1);
-
- return 0;
-}
-
-static void ep93xx_spi_disable(const struct ep93xx_spi *espi)
-{
- u32 val;
-
- val = readl(espi->mmio + SSPCR1);
- val &= ~SSPCR1_SSE;
- writel(val, espi->mmio + SSPCR1);
-
- clk_disable(espi->clk);
-}
-
static void ep93xx_spi_enable_interrupts(const struct ep93xx_spi *espi)
{
u32 val;
@@ -571,17 +544,6 @@ static void ep93xx_spi_process_message(struct ep93xx_spi *espi,
{
unsigned long timeout;
struct spi_transfer *t;
- int err;
-
- /*
- * Enable the SPI controller and its clock.
- */
- err = ep93xx_spi_enable(espi);
- if (err) {
- dev_err(&espi->pdev->dev, "failed to enable SPI controller\n");
- msg->status = err;
- return;
- }

/*
* Just to be sure: flush any data from RX FIFO.
@@ -619,7 +581,6 @@ static void ep93xx_spi_process_message(struct ep93xx_spi *espi,
* deselect the device and disable the SPI controller.
*/
ep93xx_spi_cs_control(msg->spi, false);
- ep93xx_spi_disable(espi);
}

static int ep93xx_spi_transfer_one_message(struct spi_master *master,
@@ -679,6 +640,37 @@ static irqreturn_t ep93xx_spi_interrupt(int irq, void *dev_id)
return IRQ_HANDLED;
}

+static int ep93xx_spi_prepare_hardware(struct spi_master *master)
+{
+ struct ep93xx_spi *espi = spi_master_get_devdata(master);
+ u32 val;
+ int ret;
+
+ ret = clk_enable(espi->clk);
+ if (ret)
+ return ret;
+
+ val = readl(espi->mmio + SSPCR1);
+ val |= SSPCR1_SSE;
+ writel(val, espi->mmio + SSPCR1);
+
+ return 0;
+}
+
+static int ep93xx_spi_unprepare_hardware(struct spi_master *master)
+{
+ struct ep93xx_spi *espi = spi_master_get_devdata(master);
+ u32 val;
+
+ val = readl(espi->mmio + SSPCR1);
+ val &= ~SSPCR1_SSE;
+ writel(val, espi->mmio + SSPCR1);
+
+ clk_disable(espi->clk);
+
+ return 0;
+}
+
static bool ep93xx_spi_dma_filter(struct dma_chan *chan, void *filter_param)
{
if (ep93xx_dma_chan_is_m2p(chan))
@@ -780,6 +772,8 @@ static int ep93xx_spi_probe(struct platform_device *pdev)
if (!master)
return -ENOMEM;

+ master->prepare_transfer_hardware = ep93xx_spi_prepare_hardware;
+ master->unprepare_transfer_hardware = ep93xx_spi_unprepare_hardware;
master->transfer_one_message = ep93xx_spi_transfer_one_message;
master->bus_num = pdev->id;
master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
--
2.13.0