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

[Chris Packham]

From: H Hartley Sweeten <hswee...@visionengravers.com>

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 <hswee...@visionengravers.com>
[chris: use u32 instead of unsigned int]
Signed-off-by: Chris Packham <chris.pack...@alliedtelesis.co.nz>
Reviewed-by: Andy Shevchenko <andy.shevche...@gmail.com>
---
 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