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spi: spi-ep93xx: add spi master prepare_transfer_hardware() 

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@visionengravers.com>
[chris: use u32 instead of unsigned int]
Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
hifive-unleashed-5.1
H Hartley Sweeten 2017-08-09 08:51:27 +12:00 committed by Mark Brown
parent 8447e4781f
commit 16779622be
1 changed files with 33 additions and 39 deletions
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72
drivers/spi/spi-ep93xx.c
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@ -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;