Re: [PATCH 3/7] reset: add BCM6345 reset controller driver

Álvaro Fernández Rojas
2020-06-09T15:14:10Z

Hi Philipp,

> El 9 jun 2020, a las 17:06, Philipp Zabel <p.zabel@pengutronix.de> escribió:
>
> Hi Álvaro,
>
> On Tue, 2020-06-09 at 15:42 +0200, Álvaro Fernández Rojas wrote:
>> Add support for resetting blocks through the Linux reset controller
>> subsystem for BCM63xx SoCs.
>>
>> Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
>> ---
>> drivers/reset/Kconfig | 7 ++
>> drivers/reset/Makefile | 1 +
>> drivers/reset/reset-bcm6345.c | 149 ++++++++++++++++++++++++++++++++++
>> 3 files changed, 157 insertions(+)
>> create mode 100644 drivers/reset/reset-bcm6345.c
>>
>> diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig
>> index d9efbfd29646..9f1da978cef6 100644
>> --- a/drivers/reset/Kconfig
>> +++ b/drivers/reset/Kconfig
>> @@ -41,6 +41,13 @@ config RESET_BERLIN
>> help
>> This enables the reset controller driver for Marvell Berlin SoCs.
>>
>> +config RESET_BCM6345
>> + bool "BCM6345 Reset Controller"
>> + depends on BMIPS_GENERIC || COMPILE_TEST
>> + default BMIPS_GENERIC
>> + help
>> + This enables the reset controller driver for BCM6345 SoCs.
>> +
>> config RESET_BRCMSTB
>> tristate "Broadcom STB reset controller"
>> depends on ARCH_BRCMSTB || COMPILE_TEST
>> diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile
>> index 249ed357c997..e642aae42f0f 100644
>> --- a/drivers/reset/Makefile
>> +++ b/drivers/reset/Makefile
>> @@ -6,6 +6,7 @@ obj-$(CONFIG_ARCH_TEGRA) += tegra/
>> obj-$(CONFIG_RESET_A10SR) += reset-a10sr.o
>> obj-$(CONFIG_RESET_ATH79) += reset-ath79.o
>> obj-$(CONFIG_RESET_AXS10X) += reset-axs10x.o
>> +obj-$(CONFIG_RESET_BCM6345) += reset-bcm6345.o
>> obj-$(CONFIG_RESET_BERLIN) += reset-berlin.o
>> obj-$(CONFIG_RESET_BRCMSTB) += reset-brcmstb.o
>> obj-$(CONFIG_RESET_BRCMSTB_RESCAL) += reset-brcmstb-rescal.o
>> diff --git a/drivers/reset/reset-bcm6345.c b/drivers/reset/reset-bcm6345.c
>> new file mode 100644
>> index 000000000000..088b7fdb896b
>> --- /dev/null
>> +++ b/drivers/reset/reset-bcm6345.c
>> @@ -0,0 +1,149 @@
>> +// SPDX-License-Identifier: GPL-2.0-or-later
>> +/*
>> + * BCM6345 Reset Controller Driver
>> + *
>> + * Copyright (C) 2020 Álvaro Fernández Rojas <noltari@gmail.com>
>> + */
>> +
>> +#include <linux/delay.h>
>> +#include <linux/init.h>
>> +#include <linux/io.h>
>> +#include <linux/mod_devicetable.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/reset-controller.h>
>> +
>> +#define BCM6345_RESET_NUM 32
>> +#define BCM6345_RESET_SLEEP_MIN_US 10000
>> +#define BCM6345_RESET_SLEEP_MAX_US 20000
>> +
>> +struct bcm6345_reset {
>> + struct reset_controller_dev rcdev;
>> + void __iomem *base;
>> + spinlock_t lock;
>> +};
>> +
>> +static int bcm6345_reset_update(struct bcm6345_reset *bcm6345_reset,
>> + unsigned long id, bool assert)
>> +{
>> + uint32_t val;
>> +
>> + val = __raw_readl(bcm6345_reset->base);
>> + if (assert)
>> + val &= ~BIT(id);
>> + else
>> + val |= BIT(id);
>> + __raw_writel(val, bcm6345_reset->base);
>> +
>> + return 0;
>> +}
>> +
>> +static int bcm6345_reset_assert(struct reset_controller_dev *rcdev,
>> + unsigned long id)
>> +{
>> + struct bcm6345_reset *bcm6345_reset =
>> + container_of(rcdev, struct bcm6345_reset, rcdev);
>> + unsigned long flags;
>> +
>> + spin_lock_irqsave(&bcm6345_reset->lock, flags);
>> + bcm6345_reset_update(bcm6345_reset, id, true);
>> + spin_unlock_irqrestore(&bcm6345_reset->lock, flags);
>> +
>> + return 0;
>> +}
>> +
>> +static int bcm6345_reset_deassert(struct reset_controller_dev *rcdev,
>> + unsigned long id)
>> +{
>> + struct bcm6345_reset *bcm6345_reset =
>> + container_of(rcdev, struct bcm6345_reset, rcdev);
>> + unsigned long flags;
>> +
>> + spin_lock_irqsave(&bcm6345_reset->lock, flags);
>> + bcm6345_reset_update(bcm6345_reset, id, false);
>> + spin_unlock_irqrestore(&bcm6345_reset->lock, flags);
>> +
>> + return 0;
>> +}
>> +
>> +static int bcm6345_reset_reset(struct reset_controller_dev *rcdev,
>> + unsigned long id)
>> +{
>> + struct bcm6345_reset *bcm6345_reset =
>> + container_of(rcdev, struct bcm6345_reset, rcdev);
>> + unsigned long flags;
>> +
>> + spin_lock_irqsave(&bcm6345_reset->lock, flags);
>> + usleep_range(BCM6345_RESET_SLEEP_MIN_US,
>> + BCM6345_RESET_SLEEP_MAX_US);
>
> What is the purpose of sleeping before reset assertion?

None, I must have introduced that for testing something and then I forgot to remove it. Sorry for that...

>
> If you can do without this, with I think this driver could be made to
> use reset-simple.

Yes, but only if I can add reset support with a configurable sleep range to reset-simple. Is this possible?

>
> regards
> Philipp

Best regards,
Álvaro.