Linux-i2c Archive on lore.kernel.org
 help / color / Atom feed
From: Serge Semin <Sergey.Semin@baikalelectronics.ru>
To: Jarkko Nikula <jarkko.nikula@linux.intel.com>,
	Wolfram Sang <wsa@the-dreams.de>,
	Rob Herring <robh+dt@kernel.org>,
	Frank Rowand <frowand.list@gmail.com>
Cc: Serge Semin <Sergey.Semin@baikalelectronics.ru>,
	Serge Semin <fancer.lancer@gmail.com>,
	Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>,
	Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
	Mika Westerberg <mika.westerberg@linux.intel.com>,
	<linux-mips@vger.kernel.org>, <linux-i2c@vger.kernel.org>,
	<devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Subject: [PATCH v3 01/12] scripts/dtc: check: Add 10bit/slave i2c reg flags support
Date: Wed, 27 May 2020 00:55:17 +0300
Message-ID: <20200526215528.16417-2-Sergey.Semin@baikalelectronics.ru> (raw)
In-Reply-To: <20200526215528.16417-1-Sergey.Semin@baikalelectronics.ru>

Recently the I2C-controllers slave interface support was added to the
kernel I2C subsystem. In this case Linux can be used as, for example,
a I2C EEPROM machine. See [1] for details. Other than instantiating
the EEPROM-slave device from user-space there is a way to declare the
device in dts. In this case firstly the I2C bus controller must support
the slave interface. Secondly I2C-slave sub-node of that controller
must have "reg"-property with flag I2C_OWN_SLAVE_ADDRESS set (flag is
declared in [2]). That flag is declared as (1 << 30), which when set
makes dtc unhappy about too big address set for a I2C-slave:

Warning (i2c_bus_reg): /example-2/i2c@1120000/eeprom@64: I2C bus unit address format error, expected "40000064"
Warning (i2c_bus_reg): /example-2/i2c@1120000/eeprom@64:reg: I2C address must be less than 10-bits, got "0x40000064"

Similar problem would have happened if we had set the 10-bit address
flag I2C_TEN_BIT_ADDRESS in the "reg"-property.

In order to fix the problem we suggest to alter the I2C-bus reg-check
algorithm, so one would be aware of the upper bits set. Normally if no
flag specified, the 7-bit address is expected in the "reg"-property.
If I2C_TEN_BIT_ADDRESS is set, then the 10-bit address check will be
performed. The I2C_OWN_SLAVE_ADDRESS flag will be just ignored.

[1] Documentation/i2c/slave-interface.rst
[2] include/dt-bindings/i2c/i2c.h

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: linux-mips@vger.kernel.org
Cc: linux-i2c@vger.kernel.org
---
 scripts/dtc/checks.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/scripts/dtc/checks.c b/scripts/dtc/checks.c
index 4b3c486f1399..6321fc5b7404 100644
--- a/scripts/dtc/checks.c
+++ b/scripts/dtc/checks.c
@@ -1028,6 +1028,7 @@ static void check_i2c_bus_reg(struct check *c, struct dt_info *dti, struct node
 	const char *unitname = get_unitname(node);
 	char unit_addr[17];
 	uint32_t reg = 0;
+	uint32_t addr;
 	int len;
 	cell_t *cells = NULL;
 
@@ -1044,17 +1045,21 @@ static void check_i2c_bus_reg(struct check *c, struct dt_info *dti, struct node
 	}
 
 	reg = fdt32_to_cpu(*cells);
-	snprintf(unit_addr, sizeof(unit_addr), "%x", reg);
+	addr = reg & 0x3FFFFFFFU;
+	snprintf(unit_addr, sizeof(unit_addr), "%x", addr);
 	if (!streq(unitname, unit_addr))
 		FAIL(c, dti, node, "I2C bus unit address format error, expected \"%s\"",
 		     unit_addr);
 
 	for (len = prop->val.len; len > 0; len -= 4) {
 		reg = fdt32_to_cpu(*(cells++));
-		if (reg > 0x3ff)
+		addr = reg & 0x3FFFFFFFU;
+		if ((reg & (1 << 31)) && addr > 0x3ff)
 			FAIL_PROP(c, dti, node, prop, "I2C address must be less than 10-bits, got \"0x%x\"",
-				  reg);
-
+				  addr);
+		else if (!(reg & (1 << 31)) && addr > 0x7f)
+			FAIL_PROP(c, dti, node, prop, "I2C address must be less than 7-bits, got \"0x%x\"",
+				  addr);
 	}
 }
 WARNING(i2c_bus_reg, check_i2c_bus_reg, NULL, &reg_format, &i2c_bus_bridge);
-- 
2.26.2


  reply index

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-26 21:55 [PATCH v3 00/12] i2c: designeware: Add Baikal-T1 System I2C support Serge Semin
2020-05-26 21:55 ` Serge Semin [this message]
2020-05-27  1:17   ` [PATCH v3 01/12] scripts/dtc: check: Add 10bit/slave i2c reg flags support Rob Herring
2020-05-27  9:46     ` Serge Semin
2020-05-27 11:20     ` Serge Semin
2020-05-26 21:55 ` [PATCH v3 02/12] dt-bindings: i2c: Convert DW I2C binding to DT schema Serge Semin
2020-05-27  1:20   ` Rob Herring
2020-05-26 21:55 ` [PATCH v3 03/12] dt-bindings: i2c: Discard i2c-slave flag from the DW I2C example Serge Semin
2020-05-27  9:30   ` Andy Shevchenko
2020-05-27 12:07     ` Serge Semin
2020-05-27 13:32       ` Andy Shevchenko
2020-05-26 21:55 ` [PATCH v3 04/12] dt-bindings: i2c: dw: Add Baikal-T1 SoC I2C controller Serge Semin
2020-05-26 21:55 ` [PATCH v3 05/12] i2c: designware: Use `-y` to build multi-object modules Serge Semin
2020-05-26 21:55 ` [PATCH v3 06/12] i2c: designware: slave: Set DW I2C core module dependency Serge Semin
2020-05-26 21:55 ` [PATCH v3 07/12] i2c: designware: Add Baytrail sem config DW I2C platform dependency Serge Semin
2020-05-26 21:55 ` [PATCH v3 08/12] i2c: designware: Discard Cherry Trail model flag Serge Semin
2020-05-26 21:55 ` [PATCH v3 09/12] i2c: designware: Convert driver to using regmap API Serge Semin
2020-05-26 21:55 ` [PATCH v3 10/12] i2c: designware: Retrieve quirk flags as early as possible Serge Semin
2020-05-26 21:55 ` [PATCH v3 11/12] i2c: designware: Move reg-space remapping into a dedicated function Serge Semin
2020-05-27  9:26   ` Andy Shevchenko
2020-05-27  9:50     ` Serge Semin
2020-05-27 10:18       ` Andy Shevchenko
2020-05-26 21:55 ` [PATCH v3 12/12] i2c: designware: Add Baikal-T1 System I2C support Serge Semin
2020-05-27 13:30 ` [PATCH v3 00/12] i2c: designeware: " Andy Shevchenko

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200526215528.16417-2-Sergey.Semin@baikalelectronics.ru \
    --to=sergey.semin@baikalelectronics.ru \
    --cc=Alexey.Malahov@baikalelectronics.ru \
    --cc=devicetree@vger.kernel.org \
    --cc=fancer.lancer@gmail.com \
    --cc=frowand.list@gmail.com \
    --cc=jarkko.nikula@linux.intel.com \
    --cc=linux-i2c@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mips@vger.kernel.org \
    --cc=mika.westerberg@linux.intel.com \
    --cc=robh+dt@kernel.org \
    --cc=tsbogend@alpha.franken.de \
    --cc=wsa@the-dreams.de \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-i2c Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-i2c/0 linux-i2c/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-i2c linux-i2c/ https://lore.kernel.org/linux-i2c \
		linux-i2c@vger.kernel.org
	public-inbox-index linux-i2c

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-i2c


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git