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From: Wolfram Sang <wsa+renesas@sang-engineering.com>
To: linux-i2c@vger.kernel.org
Cc: devicetree@vger.kernel.org, "Jacopo Mondi" <jacopo@jmondi.org>,
	"Niklas Söderlund" <niklas.soderlund@ragnatech.se>,
	"Wolfram Sang" <wsa+renesas@sang-engineering.com>,
	linux-kernel@vger.kernel.org, "Vladimir Zapolskiy" <vz@mleia.com>,
	linux-renesas-soc@vger.kernel.org,
	"Kieran Bingham" <kieran@bingham.xyz>,
	"Laurent Pinchart" <laurent.pinchart@ideasonboard.com>,
	"Luca Ceresoli" <luca@lucaceresoli.net>,
	linux-i3c@lists.infradead.org
Subject: [RFC PATCH 6/7] i2c: of: mark a whole array of regs as reserved
Date: Thu, 20 Feb 2020 18:24:02 +0100
Message-ID: <20200220172403.26062-7-wsa+renesas@sang-engineering.com> (raw)
In-Reply-To: <20200220172403.26062-1-wsa+renesas@sang-engineering.com>

Back then, 'reg' properties in I2C DT bindings only contained one
address and this address was assigned a device and, thus, blocked.
Meanwhile, chips using multiple addresses are common and the 'reg'
property can be an array described by 'reg-names'. This code enhances
I2C DT parsing, so it will reserve all addresses described in an array.
They will be bound to the 'dummy' driver as 'reserved' iff the first
address can be assigned successfully. If that is not the case, the array
is not further considered. If one later address of the array can not be
assigned, it will be reported but we don't bail out. The driver has to
decide if that address is critical or not.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---
 drivers/i2c/i2c-core-of.c | 68 +++++++++++++++++++++++++--------------
 1 file changed, 44 insertions(+), 24 deletions(-)

diff --git a/drivers/i2c/i2c-core-of.c b/drivers/i2c/i2c-core-of.c
index 74b9f3fbb5ef..316db0c3b3c8 100644
--- a/drivers/i2c/i2c-core-of.c
+++ b/drivers/i2c/i2c-core-of.c
@@ -21,20 +21,12 @@
 
 #include "i2c-core.h"
 
-int of_i2c_get_board_info(struct device_node *node, struct i2c_board_info *info)
+static void of_i2c_decode_board_info(struct device_node *node, u32 addr,
+				     bool first_addr, struct i2c_board_info *info)
 {
-	u32 addr;
-	int ret;
-
 	memset(info, 0, sizeof(*info));
 
-	ret = of_property_read_u32(node, "reg", &addr);
-	if (ret) {
-		pr_err("invalid reg on %pOF\n", node);
-		return ret;
-	}
-
-	if (of_modalias_node(node, info->type, sizeof(info->type)) < 0)
+	if (!first_addr || of_modalias_node(node, info->type, sizeof(info->type)) < 0)
 		strlcpy(info->type, I2C_RESERVED_DRV_NAME, sizeof(I2C_RESERVED_DRV_NAME));
 
 	if (addr & I2C_TEN_BIT_ADDRESS) {
@@ -51,11 +43,27 @@ int of_i2c_get_board_info(struct device_node *node, struct i2c_board_info *info)
 	info->of_node = node;
 	info->fwnode = of_fwnode_handle(node);
 
-	if (of_property_read_bool(node, "host-notify"))
-		info->flags |= I2C_CLIENT_HOST_NOTIFY;
+	if (first_addr) {
+		if (of_property_read_bool(node, "host-notify"))
+			info->flags |= I2C_CLIENT_HOST_NOTIFY;
+
+		if (of_get_property(node, "wakeup-source", NULL))
+			info->flags |= I2C_CLIENT_WAKE;
+	}
+}
+
+int of_i2c_get_board_info(struct device_node *node, struct i2c_board_info *info)
+{
+	u32 addr;
+	int ret;
+
+	ret = of_property_read_u32(node, "reg", &addr);
+	if (ret) {
+		pr_err("invalid reg on %pOF\n", node);
+		return ret;
+	}
 
-	if (of_get_property(node, "wakeup-source", NULL))
-		info->flags |= I2C_CLIENT_WAKE;
+	of_i2c_decode_board_info(node, addr, true, info);
 
 	return 0;
 }
@@ -64,21 +72,33 @@ EXPORT_SYMBOL_GPL(of_i2c_get_board_info);
 static struct i2c_client *of_i2c_register_device(struct i2c_adapter *adap,
 						 struct device_node *node)
 {
-	struct i2c_client *client;
+	struct i2c_client *client, *first_client = ERR_PTR(-ENOENT);
 	struct i2c_board_info info;
-	int ret;
+	bool first_reg = true;
+	struct property *prop;
+	const __be32 *cur;
+	u32 reg;
 
 	pr_debug("register %pOF\n", node);
 
-	ret = of_i2c_get_board_info(node, &info);
-	if (ret)
-		return ERR_PTR(ret);
+	of_property_for_each_u32(node, "reg", prop, cur, reg) {
+		of_i2c_decode_board_info(node, reg, first_reg, &info);
+
+		client = i2c_new_client_device(adap, &info);
+		if (IS_ERR(client)) {
+			pr_err("failure registering addr 0x%02x for %pOF\n",
+				reg, node);
+			if (first_reg)
+				return client;
+		}
 
-	client = i2c_new_client_device(adap, &info);
-	if (IS_ERR(client))
-		pr_err("failure registering %pOF\n", node);
+		if (first_reg) {
+			first_client = client;
+			first_reg = false;
+		}
+	}
 
-	return client;
+	return first_client;
 }
 
 void of_i2c_register_devices(struct i2c_adapter *adap)
-- 
2.20.1


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  parent reply index

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-20 17:23 [RFC PATCH 0/7] i2c: of: reserve unknown and ancillary addresses Wolfram Sang
2020-02-20 17:23 ` [RFC PATCH 1/7] i2c: add sanity check for parameter of i2c_verify_client() Wolfram Sang
2020-02-21  9:36   ` Geert Uytterhoeven
2020-02-20 17:23 ` [RFC PATCH 2/7] i2c: use DEFINE for the dummy driver name Wolfram Sang
2020-02-21  9:38   ` Geert Uytterhoeven
2020-02-20 17:23 ` [RFC PATCH 3/7] i2c: allow DT nodes without 'compatible' Wolfram Sang
2020-02-21  9:45   ` Geert Uytterhoeven
2020-02-21  9:48     ` Geert Uytterhoeven
2020-02-23 23:11     ` Luca Ceresoli
2020-03-12 11:19       ` Wolfram Sang
2020-03-12 11:44         ` Alexandre Belloni
2020-04-10 13:47         ` Luca Ceresoli
2020-02-26 16:30   ` Rob Herring
2020-02-20 17:24 ` [RFC PATCH 4/7] i2c: of: remove superfluous parameter from exported function Wolfram Sang
2020-02-21  9:50   ` Geert Uytterhoeven
2020-02-24  8:12   ` Luca Ceresoli
2020-02-20 17:24 ` [RFC PATCH 5/7] i2c: of: error message unification Wolfram Sang
2020-02-21  9:54   ` Geert Uytterhoeven
2020-02-20 17:24 ` Wolfram Sang [this message]
2020-02-21 10:09   ` [RFC PATCH 6/7] i2c: of: mark a whole array of regs as reserved Geert Uytterhoeven
2020-03-12 11:21     ` Wolfram Sang
2020-03-18 14:33     ` Wolfram Sang
2020-02-28 12:11   ` Luca Ceresoli
2020-02-20 17:24 ` [RFC PATCH 7/7] i2c: core: hand over reserved devices when requesting ancillary addresses Wolfram Sang
2020-02-21 10:13   ` Geert Uytterhoeven
2020-02-28 12:11     ` Luca Ceresoli
2020-03-12 11:30       ` Wolfram Sang
2020-03-12 11:21     ` Wolfram Sang
2020-03-13 12:42     ` Wolfram Sang
2020-02-21 10:15 ` [RFC PATCH 0/7] i2c: of: reserve unknown and " Geert Uytterhoeven

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