[RFC,6/7] i2c: of: mark a whole array of regs as reserved
diff mbox series

Message ID 20200220172403.26062-7-wsa+renesas@sang-engineering.com
State New
Headers show
Series
  • i2c: of: reserve unknown and ancillary addresses
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Commit Message

Wolfram Sang Feb. 20, 2020, 5:24 p.m. UTC
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(-)

Comments

Geert Uytterhoeven Feb. 21, 2020, 10:09 a.m. UTC | #1
Hi Wolfram,

On Thu, Feb 20, 2020 at 6:26 PM Wolfram Sang
<wsa+renesas@sang-engineering.com> wrote:
> 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>

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>

One comment below.

> --- 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);

Perhaps the time is ripe to start considering #address-cells, instead
of assuming 1, here ...

> +       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) {

... and especially here, if this code can ever be reused for i3c, which uses 3.

> +               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)

Gr{oetje,eeting}s,

                        Geert
Luca Ceresoli Feb. 28, 2020, 12:11 p.m. UTC | #2
Hi,

On 20/02/20 18:24, Wolfram Sang wrote:
> 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>

Reviewed-by: Luca Ceresoli <luca@lucaceresoli.net>
Wolfram Sang March 12, 2020, 11:21 a.m. UTC | #3
> > +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);
> 
> Perhaps the time is ripe to start considering #address-cells, instead
> of assuming 1, here ...

I will check both instances. Thanks, Geert!
Wolfram Sang March 18, 2020, 2:33 p.m. UTC | #4
> > +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);
> 
> Perhaps the time is ripe to start considering #address-cells, instead
> of assuming 1, here ...

I think here it is okay because we really want the first entry of the
first tuple.

> > +       of_property_for_each_u32(node, "reg", prop, cur, reg) {
> 
> ... and especially here, if this code can ever be reused for i3c, which uses 3.

But here I agree. I reimplemented the code to handle it, and it worked
with '#address-cells = <2>;' as expected. Here is the diff to this
patch:

@@ -16,6 +16,7 @@
 #include <linux/i2c.h>
 #include <linux/module.h>
 #include <linux/of.h>
+#include <linux/of_address.h>
 #include <linux/of_device.h>
 #include <linux/sysfs.h>
 
@@ -75,13 +76,14 @@ static struct i2c_client *of_i2c_register_device(struct i2c_adapter *adap,
 	struct i2c_client *client, *first_client = ERR_PTR(-ENOENT);
 	struct i2c_board_info info;
 	bool first_reg = true;
-	struct property *prop;
-	const __be32 *cur;
-	u32 reg;
+	unsigned int i = 0;
+	const __be32 *prop;
+	u16 reg;
 
 	pr_debug("register %pOF\n", node);
 
-	of_property_for_each_u32(node, "reg", prop, cur, reg) {
+	while ((prop = of_get_address(node, i++, NULL, NULL))) {
+		reg = of_read_number(prop, 1);
 		of_i2c_decode_board_info(node, reg, first_reg, &info);
 
 		client = i2c_new_client_device(adap, &info);

Thanks, Geert! I will send out the new version in a few minutes.

Patch
diff mbox series

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)