Re: [PATCH v1 08/12] ARM: stm32mp157c-dk2: add board-specific sysconf fixups

[Ahmad Fatoum <a.fatoum@pengutronix.de>]

On 17/6/19 17:07, Ahmad Fatoum wrote:
> This imports the syscfg configuration done in the vendor U-Boot's
> board_init into barebox. Only part missing is the CONFIG_DM_REGULATOR
> protected clause that adjusts SYSCFG_IOCTRLSETR for operation above
> ~50MHz. These adjustments are only undertaken if VDD < 2.7V as they're
> unsafe otherwise. As the barebox port doesn't yet support querying the
> regulator, skip these adjustments for now.
> 
> Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
> ---
>  arch/arm/boards/stm32mp157c-dk2/board.c | 94 +++++++++++++++++++++++++
>  1 file changed, 94 insertions(+)
> 
> diff --git a/arch/arm/boards/stm32mp157c-dk2/board.c b/arch/arm/boards/stm32mp157c-dk2/board.c
> index cbfe21db6a8c..5572231d525c 100644
> --- a/arch/arm/boards/stm32mp157c-dk2/board.c
> +++ b/arch/arm/boards/stm32mp157c-dk2/board.c
> @@ -4,6 +4,55 @@
>  #include <init.h>
>  #include <asm/memory.h>
>  #include <mach/stm32.h>
> +#include <mfd/syscon.h>
> +
> +#define SYSCFG_BOOTR		0x00
> +#define SYSCFG_PMCSETR		0x04
> +#define SYSCFG_IOCTRLSETR	0x18
> +#define SYSCFG_ICNR		0x1C
> +#define SYSCFG_CMPCR		0x20
> +#define SYSCFG_CMPENSETR	0x24
> +#define SYSCFG_PMCCLRR		0x44
> +
> +#define SYSCFG_BOOTR_BOOT_MASK		GENMASK(2, 0)
> +#define SYSCFG_BOOTR_BOOTPD_SHIFT	4
> +
> +#define SYSCFG_IOCTRLSETR_HSLVEN_TRACE		BIT(0)
> +#define SYSCFG_IOCTRLSETR_HSLVEN_QUADSPI	BIT(1)
> +#define SYSCFG_IOCTRLSETR_HSLVEN_ETH		BIT(2)
> +#define SYSCFG_IOCTRLSETR_HSLVEN_SDMMC		BIT(3)
> +#define SYSCFG_IOCTRLSETR_HSLVEN_SPI		BIT(4)
> +
> +#define SYSCFG_CMPCR_SW_CTRL		BIT(1)
> +#define SYSCFG_CMPCR_READY		BIT(8)
> +
> +#define SYSCFG_CMPENSETR_MPU_EN		BIT(0)
> +
> +#define SYSCFG_PMCSETR_ETH_CLK_SEL	BIT(16)
> +#define SYSCFG_PMCSETR_ETH_REF_CLK_SEL	BIT(17)
> +
> +#define SYSCFG_PMCSETR_ETH_SELMII	BIT(20)
> +
> +#define SYSCFG_PMCSETR_ETH_SEL_MASK	GENMASK(23, 16)
> +#define SYSCFG_PMCSETR_ETH_SEL_GMII_MII	(0 << 21)
> +#define SYSCFG_PMCSETR_ETH_SEL_RGMII	(1 << 21)
> +#define SYSCFG_PMCSETR_ETH_SEL_RMII	(4 << 21)
> +
> +#define pr_debug_syscfg(syscfg, reg) do {			\
> +	int ret;						\
> +	u32 val;						\
> +								\
> +	if (MSG_DEBUG > LOGLEVEL)				\
> +		break;						\
> +								\
> +	ret = regmap_read(syscfg, reg, &val);			\
> +								\
> +	if (ret == 0)						\
> +		pr_debug(#reg "= 0x%08x\n", val);		\
> +	else							\
> +		pr_debug(#reg "= ERROR (%d)\n", ret);		\
> +} while (0)
> +
>  
>  static int dk2_postcore_init(void)
>  {
> @@ -15,3 +64,48 @@ static int dk2_postcore_init(void)
>  	return 0;
>  }
>  mem_initcall(dk2_postcore_init);
> +
> +static int dk2_sysconf_init(void)
> +{
> +	struct regmap *syscfg;
> +	u32 reg;
> +
> +	if (!of_machine_is_compatible("st,stm32mp157c-dk2"))
> +		return 0;
> +
> +	// TODO this function should be skipped if TF-A is used as first stage.
> +	// Any way to determine this at runtime?

Skipping this if TF-A was loaded beforehand seems to be just an optimization
that shouldn't affect correctness. But the PSCI stuff installed by barebox
and TF-A if used may be another matter.

Rouven, any idea how to check if TF-A was first stage? Would checking if barebox
is in non-secure mode work?

> +
> +	syscfg = syscon_regmap_lookup_by_compatible("st,stm32mp157-syscfg");
> +
> +	/* interconnect update : select master using the port 1 */
> +	/* LTDC = AXI_M9 */
> +	/* GPU  = AXI_M8 */
> +	/* for now information is hardcoded */
> +	regmap_write(syscfg, SYSCFG_ICNR, BIT(9));
> +	pr_debug_syscfg(syscfg, SYSCFG_ICNR);
> +
> +	/* disable Pull-Down for boot pin connected to VDD */
> +	regmap_read(syscfg, SYSCFG_BOOTR, &reg);
> +	reg &= ~(SYSCFG_BOOTR_BOOT_MASK << SYSCFG_BOOTR_BOOTPD_SHIFT);
> +	reg |= (reg & SYSCFG_BOOTR_BOOT_MASK) << SYSCFG_BOOTR_BOOTPD_SHIFT;
> +	regmap_write(syscfg, SYSCFG_BOOTR, reg);
> +	pr_debug_syscfg(syscfg, SYSCFG_BOOTR);
> +
> +	// TODO: Port High Speed Low Voltage Pad mode Enable from U-Boot
> +
> +	/* activate automatic I/O compensation
> +	 * warning: need to ensure CSI enabled and ready in clock driver
> +	 */
> +	regmap_write(syscfg, SYSCFG_CMPENSETR, SYSCFG_CMPENSETR_MPU_EN);
> +
> +	do {
> +		regmap_read(syscfg, SYSCFG_CMPCR, &reg);
> +	} while (!(reg & SYSCFG_CMPCR_READY));
> +
> +	regmap_update_bits(syscfg, SYSCFG_CMPCR, SYSCFG_CMPCR_SW_CTRL, 0);
> +	pr_debug_syscfg(syscfg, SYSCFG_CMPCR);
> +
> +	return 0;
> +}
> +coredevice_initcall(dk2_sysconf_init);
> 

-- 
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