| Message ID | 1439066007-13951-9-git-send-email-wsa@the-dreams.de (mailing list archive) |
|---|---|
| State | Accepted |
| Delegated to: | Geert Uytterhoeven |
| Headers | show |
Hi Wolfram, On Sat, Aug 8, 2015 at 10:33 PM, Wolfram Sang <wsa@the-dreams.de> wrote: > diff --git a/Documentation/i2c/slave-interface b/Documentation/i2c/slave-interface > index 2dee4e2d62df19..61ed05cd95317f 100644 > --- a/Documentation/i2c/slave-interface > +++ b/Documentation/i2c/slave-interface > @@ -31,10 +31,13 @@ User manual > =========== > > I2C slave backends behave like standard I2C clients. So, you can instantiate > -them as described in the document 'instantiating-devices'. A quick example for > -instantiating the slave-eeprom driver from userspace at address 0x64 on bus 1: > +them as described in the document 'instantiating-devices'. The only difference > +is that i2c slave backends have their own address space. So, you have to add > +0x1000 to the address you would originally request. An example for > +instantiating the slave-eeprom driver from userspace at the 7 bit address 0x64 > +on bus 1: > > - # echo slave-24c02 0x64 > /sys/bus/i2c/devices/i2c-1/new_device > + # echo slave-24c02 0x1064 > /sys/bus/i2c/devices/i2c-1/new_device Does 0x64 still work? It's an ABI since v4.1. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds -- To unsubscribe from this list: send the line "unsubscribe linux-sh" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, Aug 10, 2015 at 03:17:03PM +0200, Geert Uytterhoeven wrote: > Hi Wolfram, > > On Sat, Aug 8, 2015 at 10:33 PM, Wolfram Sang <wsa@the-dreams.de> wrote: > > diff --git a/Documentation/i2c/slave-interface b/Documentation/i2c/slave-interface > > index 2dee4e2d62df19..61ed05cd95317f 100644 > > --- a/Documentation/i2c/slave-interface > > +++ b/Documentation/i2c/slave-interface > > @@ -31,10 +31,13 @@ User manual > > =========== > > > > I2C slave backends behave like standard I2C clients. So, you can instantiate > > -them as described in the document 'instantiating-devices'. A quick example for > > -instantiating the slave-eeprom driver from userspace at address 0x64 on bus 1: > > +them as described in the document 'instantiating-devices'. The only difference > > +is that i2c slave backends have their own address space. So, you have to add > > +0x1000 to the address you would originally request. An example for > > +instantiating the slave-eeprom driver from userspace at the 7 bit address 0x64 > > +on bus 1: > > > > - # echo slave-24c02 0x64 > /sys/bus/i2c/devices/i2c-1/new_device > > + # echo slave-24c02 0x1064 > /sys/bus/i2c/devices/i2c-1/new_device > > Does 0x64 still work? It's an ABI since v4.1. Yes, you'll see the warning from patch 9.
diff --git a/Documentation/i2c/slave-interface b/Documentation/i2c/slave-interface index 2dee4e2d62df19..61ed05cd95317f 100644 --- a/Documentation/i2c/slave-interface +++ b/Documentation/i2c/slave-interface @@ -31,10 +31,13 @@ User manual =========== I2C slave backends behave like standard I2C clients. So, you can instantiate -them as described in the document 'instantiating-devices'. A quick example for -instantiating the slave-eeprom driver from userspace at address 0x64 on bus 1: +them as described in the document 'instantiating-devices'. The only difference +is that i2c slave backends have their own address space. So, you have to add +0x1000 to the address you would originally request. An example for +instantiating the slave-eeprom driver from userspace at the 7 bit address 0x64 +on bus 1: - # echo slave-24c02 0x64 > /sys/bus/i2c/devices/i2c-1/new_device + # echo slave-24c02 0x1064 > /sys/bus/i2c/devices/i2c-1/new_device Each backend should come with separate documentation to describe its specific behaviour and setup. diff --git a/Documentation/i2c/ten-bit-addresses b/Documentation/i2c/ten-bit-addresses index cdfe13901b99cb..7b2d11e53a49f1 100644 --- a/Documentation/i2c/ten-bit-addresses +++ b/Documentation/i2c/ten-bit-addresses @@ -2,6 +2,10 @@ The I2C protocol knows about two kinds of device addresses: normal 7 bit addresses, and an extended set of 10 bit addresses. The sets of addresses do not intersect: the 7 bit address 0x10 is not the same as the 10 bit address 0x10 (though a single device could respond to both of them). +To avoid ambiguity, the user sees 10 bit addresses mapped to a different +address space, namely 0xa000-0xa3ff. The leading 0xa (= 10) represents the +10 bit mode. This is used for creating device names in sysfs. It is also +needed when instantiating 10 bit devices via the new_device file in sysfs. I2C messages to and from 10-bit address devices have a different format. See the I2C specification for the details. diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index 24c96dd0a5bee4..4c1f31f039964b 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -1156,6 +1156,16 @@ i2c_sysfs_new_device(struct device *dev, struct device_attribute *attr, return -EINVAL; } + if ((info.addr & I2C_ADDR_OFFSET_TEN_BIT) == I2C_ADDR_OFFSET_TEN_BIT) { + info.addr &= ~I2C_ADDR_OFFSET_TEN_BIT; + info.flags |= I2C_CLIENT_TEN; + } + + if (info.addr & I2C_ADDR_OFFSET_SLAVE) { + info.addr &= ~I2C_ADDR_OFFSET_SLAVE; + info.flags |= I2C_CLIENT_SLAVE; + } + client = i2c_new_device(adap, &info); if (!client) return -EINVAL; @@ -1207,7 +1217,7 @@ i2c_sysfs_delete_device(struct device *dev, struct device_attribute *attr, i2c_adapter_depth(adap)); list_for_each_entry_safe(client, next, &adap->userspace_clients, detected) { - if (client->addr == addr) { + if (i2c_encode_flags_to_addr(client) == addr) { dev_info(dev, "%s: Deleting device %s at 0x%02hx\n", "delete_device", client->name, client->addr);