[PATCH v2 2/4] spi: s3c64xx: support custom value of internal clock divider

[Chanho Park]

> > Modern exynos SoCs such as Exynos Auto v9 has different internal clock
> > divider, for example "4". To support this internal value, this adds
> > clk_div of the s3c64xx_spi_port_config and assign "2" as the default
> > value to existing s3c64xx_spi_port_config.
> >
> > Signed-off-by: Chanho Park <chanho61.park at samsung.com>
> > ---
> >  drivers/spi/spi-s3c64xx.c | 28 ++++++++++++++++++++--------
> >  1 file changed, 20 insertions(+), 8 deletions(-)
> >
> > diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
> > index b3c50c7665fc..51a0e830441b 100644
> > --- a/drivers/spi/spi-s3c64xx.c
> > +++ b/drivers/spi/spi-s3c64xx.c
> > @@ -131,6 +131,7 @@ struct s3c64xx_spi_dma_data {
> >   * @fifo_lvl_mask: Bit-mask for {TX|RX}_FIFO_LVL bits in SPI_STATUS
> register.
> >   * @rx_lvl_offset: Bit offset of RX_FIFO_LVL bits in SPI_STATUS regiter.
> >   * @tx_st_done: Bit offset of TX_DONE bit in SPI_STATUS regiter.
> > + * @clk_div: Internal clock divider, if not specified, use 2 as the
> default.
> >   * @quirks: Bitmask of known quirks
> >   * @high_speed: True, if the controller supports HIGH_SPEED_EN bit.
> >   * @clk_from_cmu: True, if the controller does not include a clock
> > mux and @@ -148,6 +149,7 @@ struct s3c64xx_spi_port_config {
> >  	int	rx_lvl_offset;
> >  	int	tx_st_done;
> >  	int	quirks;
> > +	int	clk_div;
> >  	bool	high_speed;
> >  	bool	clk_from_cmu;
> >  	bool	clk_ioclk;
> > @@ -620,6 +622,7 @@ static int s3c64xx_spi_config(struct
> s3c64xx_spi_driver_data *sdd)
> >  	void __iomem *regs = sdd->regs;
> >  	int ret;
> >  	u32 val;
> > +	u32 div = sdd->port_conf->clk_div;
> >
> >  	/* Disable Clock */
> >  	if (!sdd->port_conf->clk_from_cmu) { @@ -668,16 +671,15 @@ static
> > int s3c64xx_spi_config(struct s3c64xx_spi_driver_data *sdd)
> >  	writel(val, regs + S3C64XX_SPI_MODE_CFG);
> >
> >  	if (sdd->port_conf->clk_from_cmu) {
> > -		/* The src_clk clock is divided internally by 2 */
> > -		ret = clk_set_rate(sdd->src_clk, sdd->cur_speed * 2);
> > +		ret = clk_set_rate(sdd->src_clk, sdd->cur_speed * div);
> >  		if (ret)
> >  			return ret;
> > -		sdd->cur_speed = clk_get_rate(sdd->src_clk) / 2;
> > +		sdd->cur_speed = clk_get_rate(sdd->src_clk) / div;
> >  	} else {
> >  		/* Configure Clock */
> >  		val = readl(regs + S3C64XX_SPI_CLK_CFG);
> >  		val &= ~S3C64XX_SPI_PSR_MASK;
> > -		val |= ((clk_get_rate(sdd->src_clk) / sdd->cur_speed / 2 - 1)
> > +		val |= ((clk_get_rate(sdd->src_clk) / sdd->cur_speed / div -
> 1)
> >  				& S3C64XX_SPI_PSR_MASK);
> >  		writel(val, regs + S3C64XX_SPI_CLK_CFG);
> >
> > @@ -871,6 +873,7 @@ static int s3c64xx_spi_setup(struct spi_device *spi)
> >  	struct s3c64xx_spi_csinfo *cs = spi->controller_data;
> >  	struct s3c64xx_spi_driver_data *sdd;
> >  	int err;
> > +	u32 div = 2;
> 
> This assignment is not effective - shortly later is being overwritten.

I forgot to remove this. I'll drop the assignment.

Best Regards,
Chanho Park