From: Jonathan Cameron <jic23@kernel.org>
To: Gatien CHEVALLIER <gatien.chevallier@foss.st.com>
Cc: <Oleksii_Moisieiev@epam.com>, <gregkh@linuxfoundation.org>,
<herbert@gondor.apana.org.au>, <davem@davemloft.net>,
<robh+dt@kernel.org>, <krzysztof.kozlowski+dt@linaro.org>,
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<olivier.moysan@foss.st.com>, <arnaud.pouliquen@foss.st.com>,
<mchehab@kernel.org>, <fabrice.gasnier@foss.st.com>,
<ulf.hansson@linaro.org>, <edumazet@google.com>,
<kuba@kernel.org>, <pabeni@redhat.com>,
<linux-crypto@vger.kernel.org>, <devicetree@vger.kernel.org>,
<linux-stm32@st-md-mailman.stormreply.com>,
<linux-arm-kernel@lists.infradead.org>,
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<linux-i2c@vger.kernel.org>, <linux-iio@vger.kernel.org>,
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<linux-mmc@vger.kernel.org>, <netdev@vger.kernel.org>,
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<linux-spi@vger.kernel.org>, <linux-usb@vger.kernel.org>,
Loic PALLARDY <loic.pallardy@st.com>
Subject: Re: [PATCH v3 4/6] bus: stm32_sys_bus: add support for STM32MP15 and STM32MP13 system bus
Date: Wed, 8 Feb 2023 19:08:33 +0000 [thread overview]
Message-ID: <20230208190833.532cd60c@jic23-huawei> (raw)
In-Reply-To: <d6c659d8-2e5c-cb60-d950-685c4ba319e2@foss.st.com>
On Tue, 7 Feb 2023 15:12:23 +0100
Gatien CHEVALLIER <gatien.chevallier@foss.st.com> wrote:
> Hi Jonathan,
>
> On 1/28/23 17:12, Jonathan Cameron wrote:
> > On Fri, 27 Jan 2023 17:40:38 +0100
> > Gatien Chevallier <gatien.chevallier@foss.st.com> wrote:
> >
> >> This driver is checking the access rights of the different
> >> peripherals connected to the system bus. If access is denied,
> >> the associated device tree node is skipped so the platform bus
> >> does not probe it.
> >>
> >> Signed-off-by: Gatien Chevallier <gatien.chevallier@foss.st.com>
> >> Signed-off-by: Loic PALLARDY <loic.pallardy@st.com>
> >
> > Hi Gatien,
> >
> > A few comments inline,
> >
> > Thanks,
> >
> > Jonathan
> >
> >> diff --git a/drivers/bus/stm32_sys_bus.c b/drivers/bus/stm32_sys_bus.c
> >> new file mode 100644
> >> index 000000000000..c12926466bae
> >> --- /dev/null
> >> +++ b/drivers/bus/stm32_sys_bus.c
> >> @@ -0,0 +1,168 @@
> >> +// SPDX-License-Identifier: GPL-2.0
> >> +/*
> >> + * Copyright (C) 2023, STMicroelectronics - All Rights Reserved
> >> + */
> >> +
> >> +#include <linux/bitfield.h>
> >> +#include <linux/bits.h>
> >> +#include <linux/device.h>
> >> +#include <linux/err.h>
> >> +#include <linux/io.h>
> >> +#include <linux/init.h>
> >> +#include <linux/kernel.h>
> >> +#include <linux/module.h>
> >> +#include <linux/of.h>
> >> +#include <linux/of_platform.h>
> >> +#include <linux/platform_device.h>
> >> +
> >> +/* ETZPC peripheral as firewall bus */
> >> +/* ETZPC registers */
> >> +#define ETZPC_DECPROT 0x10
> >> +
> >> +/* ETZPC miscellaneous */
> >> +#define ETZPC_PROT_MASK GENMASK(1, 0)
> >> +#define ETZPC_PROT_A7NS 0x3
> >> +#define ETZPC_DECPROT_SHIFT 1
> >
> > This define makes the code harder to read. What we care about is
> > the number of bits in the register divided by number of entries.
> > (which is 2) hence the shift by 1. See below for more on this.
> >
> >
> >> +
> >> +#define IDS_PER_DECPROT_REGS 16
> >
> >> +#define STM32MP15_ETZPC_ENTRIES 96
> >> +#define STM32MP13_ETZPC_ENTRIES 64
> >
> > These defines just make the code harder to check.
> > They aren't magic numbers, but rather just telling us how many
> > entries there are, so I would just put them in the structures directly.
> > Their use make it clear what they are without needing to give them a name.
> >
>
> Honestly, I'd rather read the hardware configuration registers to get
> this information instead of differentiating MP13/15. Would you agree on
> that?
Sure, if they are discoverable even better.
next prev parent reply other threads:[~2023-02-08 18:54 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-27 16:40 [PATCH v3 0/6] Introduce STM32 system bus Gatien Chevallier
2023-01-27 16:40 ` [PATCH v3 1/6] dt-bindings: Document common device controller bindings Gatien Chevallier
2023-01-27 16:49 ` Krzysztof Kozlowski
2023-01-27 17:00 ` Gatien CHEVALLIER
2023-01-27 16:40 ` [PATCH v3 2/6] dt-bindings: treewide: add feature-domains description in binding files Gatien Chevallier
2023-01-28 15:46 ` Jonathan Cameron
2023-02-03 20:57 ` Rob Herring
2023-01-27 16:40 ` [PATCH v3 3/6] dt-bindings: bus: add STM32 System Bus Gatien Chevallier
2023-01-28 15:48 ` Jonathan Cameron
2023-02-07 13:31 ` Gatien CHEVALLIER
2023-01-27 16:40 ` [PATCH v3 4/6] bus: stm32_sys_bus: add support for STM32MP15 and STM32MP13 system bus Gatien Chevallier
2023-01-28 16:12 ` Jonathan Cameron
2023-02-07 14:12 ` Gatien CHEVALLIER
2023-02-08 19:08 ` Jonathan Cameron [this message]
2023-01-27 16:40 ` [PATCH v3 5/6] ARM: dts: stm32: add ETZPC as a system bus for STM32MP15x boards Gatien Chevallier
2023-02-09 7:51 ` Uwe Kleine-König
2023-01-27 16:40 ` [PATCH v3 6/6] ARM: dts: stm32: add ETZPC as a system bus for STM32MP13x boards Gatien Chevallier
2023-02-09 7:46 ` [Linux-stm32] " Ahmad Fatoum
2023-02-09 8:10 ` Ahmad Fatoum
2023-02-13 10:54 ` Gatien CHEVALLIER
2023-02-13 11:27 ` Ahmad Fatoum
2023-02-27 11:26 ` Gatien CHEVALLIER
2023-04-21 10:19 ` Oleksii Moisieiev
2023-04-25 7:56 ` Gatien CHEVALLIER
2023-07-05 17:35 ` [PATCH v3 0/6] Introduce STM32 system bus Gatien CHEVALLIER
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