Re: [PATCH] reset: socfpga: add an early reset driver for SoCFPGA

From: Dinh Nguyen
Date: Fri Oct 05 2018 - 11:17:16 EST




On 10/04/2018 04:53 AM, Philipp Zabel wrote:
> Hi Dinh,
>
> On Mon, 2018-09-17 at 09:50 -0500, Dinh Nguyen wrote:
>> Create a separate reset driver that uses the reset operations in reset-simple.
>> The reset driver for the SoCFPGA platform needs to register early in order to
>> be able bring online timers that needed early in the kernel bootup.
>>
>> Signed-off-by: Dinh Nguyen <dinguyen@xxxxxxxxxx>
>> ---
>> arch/arm/mach-socfpga/socfpga.c | 4 ++
>> drivers/reset/Kconfig | 7 ++++
>> drivers/reset/Makefile | 1 +
>> drivers/reset/reset-simple.c | 17 ---------
>> drivers/reset/reset-socfpga.c | 85 +++++++++++++++++++++++++++++++++++++++++
>> 5 files changed, 97 insertions(+), 17 deletions(-)
>> create mode 100644 drivers/reset/reset-socfpga.c
>>
>> diff --git a/arch/arm/mach-socfpga/socfpga.c b/arch/arm/mach-socfpga/socfpga.c
>> index dde14f7..cc64576 100644
>> --- a/arch/arm/mach-socfpga/socfpga.c
>> +++ b/arch/arm/mach-socfpga/socfpga.c
>> @@ -32,6 +32,8 @@ void __iomem *rst_manager_base_addr;
>> void __iomem *sdr_ctl_base_addr;
>> unsigned long socfpga_cpu1start_addr;
>>
>> +extern void __init socfpga_reset_init(void);
>> +
>> void __init socfpga_sysmgr_init(void)
>> {
>> struct device_node *np;
>> @@ -64,6 +66,7 @@ static void __init socfpga_init_irq(void)
>>
>> if (IS_ENABLED(CONFIG_EDAC_ALTERA_OCRAM))
>> socfpga_init_ocram_ecc();
>> + socfpga_reset_init();
>> }
>>
>> static void __init socfpga_arria10_init_irq(void)
>> @@ -74,6 +77,7 @@ static void __init socfpga_arria10_init_irq(void)
>> socfpga_init_arria10_l2_ecc();
>> if (IS_ENABLED(CONFIG_EDAC_ALTERA_OCRAM))
>> socfpga_init_arria10_ocram_ecc();
>> + socfpga_reset_init();
>> }
>>
>> static void socfpga_cyclone5_restart(enum reboot_mode mode, const char *cmd)
>> diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig
>> index 13d28fd..dcc5f1d 100644
>> --- a/drivers/reset/Kconfig
>> +++ b/drivers/reset/Kconfig
>> @@ -119,6 +119,13 @@ config RESET_STM32MP157
>> help
>> This enables the RCC reset controller driver for STM32 MPUs.
>>
>> +config RESET_SOCFPGA
>> + bool "SoCFPGA Reset Driver" if COMPILE_TEST && !ARCH_SOCFPGA
>> + default ARCH_SOCFPGA
>> + select RESET_SIMPLE
>> + help
>> + This enables the reset driver for SoCFPGA.
>> +
>> config RESET_SUNXI
>> bool "Allwinner SoCs Reset Driver" if COMPILE_TEST && !ARCH_SUNXI
>> default ARCH_SUNXI
>> diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile
>> index 4243c38..d09bb41 100644
>> --- a/drivers/reset/Makefile
>> +++ b/drivers/reset/Makefile
>> @@ -18,6 +18,7 @@ obj-$(CONFIG_RESET_PISTACHIO) += reset-pistachio.o
>> obj-$(CONFIG_RESET_QCOM_AOSS) += reset-qcom-aoss.o
>> obj-$(CONFIG_RESET_SIMPLE) += reset-simple.o
>> obj-$(CONFIG_RESET_STM32MP157) += reset-stm32mp1.o
>> +obj-$(CONFIG_RESET_SOCFPGA) += reset-socfpga.o
>> obj-$(CONFIG_RESET_SUNXI) += reset-sunxi.o
>> obj-$(CONFIG_RESET_TI_SCI) += reset-ti-sci.o
>> obj-$(CONFIG_RESET_TI_SYSCON) += reset-ti-syscon.o
>> diff --git a/drivers/reset/reset-simple.c b/drivers/reset/reset-simple.c
>> index a91107f..483824f 100644
>> --- a/drivers/reset/reset-simple.c
>> +++ b/drivers/reset/reset-simple.c
>> @@ -106,21 +106,12 @@ struct reset_simple_devdata {
>> bool status_active_low;
>> };
>>
>> -#define SOCFPGA_NR_BANKS 8
>> -
>> -static const struct reset_simple_devdata reset_simple_socfpga = {
>> - .reg_offset = 0x10,
>
> Before, the default reg_offset for DTs missing the altr,modrst-offset
> property was 0x10 ...
>
>> - .nr_resets = SOCFPGA_NR_BANKS * 32,
>> - .status_active_low = true,
>> -};
>> -
> [...]
>> +static int a10_reset_init(struct device_node *np)
>> +{
>> + struct reset_simple_data *data;
>> + struct resource res;
>> + resource_size_t size;
>> + int ret;
>> + u32 reg_offset = 0;
>
> ... now it is 0x0.
> I think this should be
>
> u32 reg_offset = 0x10;
>
> to avoid breaking SocFPGA with ancient device trees.
>
>> +
>> + data = kzalloc(sizeof(*data), GFP_KERNEL);
>> + if (!data)
>> + return -ENOMEM;
>> +
>> + ret = of_address_to_resource(np, 0, &res);
>> + if (ret)
>> + goto err_alloc;
>> +
>> + size = resource_size(&res);
>> + if (!request_mem_region(res.start, size, np->name)) {
>> + ret = -EBUSY;
>> + goto err_alloc;
>> + }
>> +
>> + data->membase = ioremap(res.start, size);
>> + if (!data->membase) {
>> + ret = -ENOMEM;
>> + goto err_alloc;
>> + }
>> +
>> + if (of_property_read_u32(np, "altr,modrst-offset", &reg_offset))
>> + pr_warn("missing altr,modrst-offset property, assuming 0x0\n");
>> + data->membase += reg_offset;
>> +
>> + spin_lock_init(&data->lock);
>> +
>> + data->rcdev.owner = THIS_MODULE;
>> + data->rcdev.nr_resets = 32 * 8;
>
> Could we keep the SOCFPGA_NR_BANKS #define to reduce the amount of magic
> numbers?
>
> I can make both changes when applying if you want.
>

If you don't mind, that would be great!

Thanks,
Dinh