Subject: [PATCH 2/2] ARM: davinci: da850: use clk->set_parent for async3

From: [email-masked] (David Lechner)
Date: Sat, 16 Apr 2016 14:31:27 -0500

On 04/14/2016 02:13 PM, David Lechner wrote:
> The da850 family of processors has an async3 clock domain that can be
> muxed to either pll0_sysclk2 or pll1_sysclk2. Now that the davinci clocks
> have a set_parent callback, we can use this to control the async3 mux
> instead of a stand-alone function.
>
> This adds a new async3_clk and sets the appropriate child clocks. The
> default is use to pll1_sysclk2 since it is not affected by processor
> frequency scaling.
>
> Signed-off-by: David Lechner <[email-masked]>
> ---
>
> v4 changes:
>
> * Fixed strict checkpatch complaint about {} in if/else
>
>
>   arch/arm/mach-davinci/da850.c | 82 ++++++++++++++++++-------------------------
>   1 file changed, 34 insertions(+), 48 deletions(-)
>
> diff --git a/arch/arm/mach-davinci/da850.c b/arch/arm/mach-davinci/da850.c
> index 1f85bbc..ace7433 100644
> --- a/arch/arm/mach-davinci/da850.c
> +++ b/arch/arm/mach-davinci/da850.c
> @@ -34,9 +34,6 @@
>   #include "clock.h"
>   #include "mux.h"
>
> -/* SoC specific clock flags */
> -#define DA850_CLK_ASYNC3	BIT(16)
> -
>   #define DA850_PLL1_BASE		0x01e1a000
>   #define DA850_TIMER64P2_BASE	0x01f0c000
>   #define DA850_TIMER64P3_BASE	0x01f0d000
> @@ -161,6 +158,33 @@ static struct clk pll1_sysclk3 = {
>   	.div_reg	= PLLDIV3,
>   };
>
> +static int da850_async3_set_parent(struct clk *clk, struct clk *parent)
> +{
> +	u32 val;
> +
> +	val = readl(DA8XX_SYSCFG0_VIRT(DA8XX_CFGCHIP3_REG));
> +
> +	/* Set the USB 1.1 PHY clock mux based on the parent clock. */

I seem to have regressed here since the last revision, this is supposed 
to read:

	/* Set the async3 clock domain mux based on the parent clock. */

Although now that I am looking at it again, it doesn't really add 
anything useful and could be omitted altogether.

> +	if (parent == &pll0_sysclk2) {
> +		val &= ~CFGCHIP3_ASYNC3_CLKSRC;
> +	} else if (parent == &pll1_sysclk2) {
> +		val |= CFGCHIP3_ASYNC3_CLKSRC;
> +	} else {
> +		pr_err("Bad parent on async3 clock mux\n");
> +		return -EINVAL;
> +	}
> +
> +	writel(val, DA8XX_SYSCFG0_VIRT(DA8XX_CFGCHIP3_REG));
> +
> +	return 0;
> +}
> +
> +static struct clk async3_clk = {
> +	.name		= "async3",
> +	.parent		= &pll1_sysclk2,
> +	.set_parent	= da850_async3_set_parent,
> +};
> +
>   static struct clk i2c0_clk = {
>   	.name		= "i2c0",
>   	.parent		= &pll0_aux_clk,
> @@ -234,18 +258,16 @@ static struct clk uart0_clk = {
>
>   static struct clk uart1_clk = {
>   	.name		= "uart1",
> -	.parent		= &pll0_sysclk2,
> +	.parent		= &async3_clk,
>   	.lpsc		= DA8XX_LPSC1_UART1,
>   	.gpsc		= 1,
> -	.flags		= DA850_CLK_ASYNC3,
>   };
>
>   static struct clk uart2_clk = {
>   	.name		= "uart2",
> -	.parent		= &pll0_sysclk2,
> +	.parent		= &async3_clk,
>   	.lpsc		= DA8XX_LPSC1_UART2,
>   	.gpsc		= 1,
> -	.flags		= DA850_CLK_ASYNC3,
>   };
>
>   static struct clk aintc_clk = {
> @@ -300,10 +322,9 @@ static struct clk emac_clk = {
>
>   static struct clk mcasp_clk = {
>   	.name		= "mcasp",
> -	.parent		= &pll0_sysclk2,
> +	.parent		= &async3_clk,
>   	.lpsc		= DA8XX_LPSC1_McASP0,
>   	.gpsc		= 1,
> -	.flags		= DA850_CLK_ASYNC3,
>   };
>
>   static struct clk lcdc_clk = {
> @@ -355,10 +376,9 @@ static struct clk spi0_clk = {
>
>   static struct clk spi1_clk = {
>   	.name		= "spi1",
> -	.parent		= &pll0_sysclk2,
> +	.parent		= &async3_clk,
>   	.lpsc		= DA8XX_LPSC1_SPI1,
>   	.gpsc		= 1,
> -	.flags		= DA850_CLK_ASYNC3,
>   };
>
>   static struct clk vpif_clk = {
> @@ -386,10 +406,9 @@ static struct clk dsp_clk = {
>
>   static struct clk ehrpwm_clk = {
>   	.name		= "ehrpwm",
> -	.parent		= &pll0_sysclk2,
> +	.parent		= &async3_clk,
>   	.lpsc		= DA8XX_LPSC1_PWM,
>   	.gpsc		= 1,
> -	.flags		= DA850_CLK_ASYNC3,
>   };
>
>   #define DA8XX_EHRPWM_TBCLKSYNC	BIT(12)
> @@ -421,10 +440,9 @@ static struct clk ehrpwm_tbclk = {
>
>   static struct clk ecap_clk = {
>   	.name		= "ecap",
> -	.parent		= &pll0_sysclk2,
> +	.parent		= &async3_clk,
>   	.lpsc		= DA8XX_LPSC1_ECAP,
>   	.gpsc		= 1,
> -	.flags		= DA850_CLK_ASYNC3,
>   };
>
>   static struct clk_lookup da850_clks[] = {
> @@ -442,6 +460,7 @@ static struct clk_lookup da850_clks[] = {
>   	CLK(NULL,		"pll1_aux",	&pll1_aux_clk),
>   	CLK(NULL,		"pll1_sysclk2",	&pll1_sysclk2),
>   	CLK(NULL,		"pll1_sysclk3",	&pll1_sysclk3),
> +	CLK(NULL,		"async3",	&async3_clk),
>   	CLK("i2c_davinci.1",	NULL,		&i2c0_clk),
>   	CLK(NULL,		"timer0",	&timerp64_0_clk),
>   	CLK("davinci-wdt",	NULL,		&timerp64_1_clk),
> @@ -909,30 +928,6 @@ static struct davinci_timer_info da850_timer_info = {
>   	.clocksource_id	= T0_TOP,
>   };
>
> -static void da850_set_async3_src(int pllnum)
> -{
> -	struct clk *clk, *newparent = pllnum ? &pll1_sysclk2 : &pll0_sysclk2;
> -	struct clk_lookup *c;
> -	unsigned int v;
> -	int ret;
> -
> -	for (c = da850_clks; c->clk; c++) {
> -		clk = c->clk;
> -		if (clk->flags & DA850_CLK_ASYNC3) {
> -			ret = clk_set_parent(clk, newparent);
> -			WARN(ret, "DA850: unable to re-parent clock %s",
> -								clk->name);
> -		}
> -       }
> -
> -	v = __raw_readl(DA8XX_SYSCFG0_VIRT(DA8XX_CFGCHIP3_REG));
> -	if (pllnum)
> -		v |= CFGCHIP3_ASYNC3_CLKSRC;
> -	else
> -		v &= ~CFGCHIP3_ASYNC3_CLKSRC;
> -	__raw_writel(v, DA8XX_SYSCFG0_VIRT(DA8XX_CFGCHIP3_REG));
> -}
> -
>   #ifdef CONFIG_CPU_FREQ
>   /*
>    * Notes:
> @@ -1328,15 +1323,6 @@ void __init da850_init(void)
>   	if (WARN(!da8xx_syscfg1_base, "Unable to map syscfg1 module"))
>   		return;
>
> -	/*
> -	 * Move the clock source of Async3 domain to PLL1 SYSCLK2.
> -	 * This helps keeping the peripherals on this domain insulated
> -	 * from CPU frequency changes caused by DVFS. The firmware sets
> -	 * both PLL0 and PLL1 to the same frequency so, there should not
> -	 * be any noticeable change even in non-DVFS use cases.
> -	 */
> -	da850_set_async3_src(1);
> -
>   	/* Unlock writing to PLL0 registers */
>   	v = __raw_readl(DA8XX_SYSCFG0_VIRT(DA8XX_CFGCHIP0_REG));
>   	v &= ~CFGCHIP0_PLL_MASTER_LOCK;
>