[U-Boot,5/8] clk: rockchip: Add rk3328 Saradc clock support

[Philipp Tomsich]

On Wed, 13 Sep 2017, David Wu wrote:

> The clk_saradc is dividing from the 24M, clk_saradc=24MHz/(saradc_div_con+1).
> Saradc integer divider control register is 10-bits width.
>
> Signed-off-by: David Wu <david.wu at rock-chips.com>

Reviewed-by: Philipp Tomsich <philipp.tomsich at theobroma-systems.com>

See below for comments.

> ---
> drivers/clk/rockchip/clk_rk3328.c | 37 +++++++++++++++++++++++++++++++++++++
> 1 file changed, 37 insertions(+)
>
> diff --git a/drivers/clk/rockchip/clk_rk3328.c b/drivers/clk/rockchip/clk_rk3328.c
> index c3a6650..e1ae7b2 100644
> --- a/drivers/clk/rockchip/clk_rk3328.c
> +++ b/drivers/clk/rockchip/clk_rk3328.c
> @@ -115,6 +115,7 @@ enum {
> 	/* CLKSEL_CON23 */
> 	CLK_SARADC_DIV_CON_SHIFT	= 0,
> 	CLK_SARADC_DIV_CON_MASK		= 0x3ff << CLK_SARADC_DIV_CON_SHIFT,

Can we use GENMASK here?

> +	CLK_SARADC_DIV_CON_WIDTH	= 10,
>
> 	/* CLKSEL_CON24 */
> 	CLK_PWM_PLL_SEL_CPLL		= 0,
> @@ -180,6 +181,11 @@ enum {
> #define PLL_DIV_MIN	16
> #define PLL_DIV_MAX	3200
>
> +static inline u32 extract_bits(u32 val, unsigned width, unsigned shift)
> +{
> +	return (val >> shift) & ((1 << width) - 1);

Can we use the functions from bitfield.h, please?

> +}
> +
> /*
>  * How to calculate the PLL(from TRM V0.3 Part 1 Page 63):
>  * Formulas also embedded within the Fractional PLL Verilog model:
> @@ -478,6 +484,31 @@ static ulong rk3328_pwm_set_clk(struct rk3328_cru *cru, uint hz)
> 	return DIV_TO_RATE(GPLL_HZ, div);
> }
>
> +static ulong rk3328_saradc_get_clk(struct rk3328_cru *cru)
> +{
> +	u32 div, val;
> +
> +	val = readl(&cru->clksel_con[23]);
> +	div = extract_bits(val, CLK_SARADC_DIV_CON_WIDTH,
> +			   CLK_SARADC_DIV_CON_SHIFT);
> +
> +	return DIV_TO_RATE(OSC_HZ, div);
> +}
> +
> +static ulong rk3328_saradc_set_clk(struct rk3328_cru *cru, uint hz)
> +{
> +	int src_clk_div;
> +
> +	src_clk_div = DIV_ROUND_UP(OSC_HZ, hz) - 1;
> +	assert(src_clk_div < 128);
> +
> +	rk_clrsetreg(&cru->clksel_con[23],
> +		     CLK_SARADC_DIV_CON_MASK,
> +		     src_clk_div << CLK_SARADC_DIV_CON_SHIFT);
> +
> +	return rk3328_saradc_get_clk(cru);
> +}
> +
> static ulong rk3328_clk_get_rate(struct clk *clk)
> {
> 	struct rk3328_clk_priv *priv = dev_get_priv(clk->dev);
> @@ -501,6 +532,9 @@ static ulong rk3328_clk_get_rate(struct clk *clk)
> 	case SCLK_PWM:
> 		rate = rk3328_pwm_get_clk(priv->cru);
> 		break;
> +	case SCLK_SARADC:
> +		rate = rk3328_saradc_get_clk(priv->cru);
> +		break;
> 	default:
> 		return -ENOENT;
> 	}
> @@ -531,6 +565,9 @@ static ulong rk3328_clk_set_rate(struct clk *clk, ulong rate)
> 	case SCLK_PWM:
> 		ret = rk3328_pwm_set_clk(priv->cru, rate);
> 		break;
> +	case SCLK_SARADC:
> +		ret = rk3328_saradc_set_clk(priv->cru, rate);
> +		break;
> 	default:
> 		return -ENOENT;
> 	}
>