Re: [RFC] i2c: add deprecation warning for class based instantiation
From: Grygorii Strashko
Date: Wed Jun 19 2013 - 14:26:16 EST
Hi Wolfram,
On 06/19/2013 01:15 PM, Wolfram Sang wrote:
On Fri, Jun 07, 2013 at 11:09:26AM +0200, Wolfram Sang wrote:
Class based instantiation can cause huge delays when booting. This
mechanism was used when it was not possible to describe slaves on I2C
busses. We now have other mechanisms, so most embedded I2C will not need
classes and it was explicitly not recommended to use them. Add a
deprecation warning for drivers who want to disable class based in the
near future to gain boot-up time, so users relying on this technique can
switch to something better. They really should.
Signed-off-by: Wolfram Sang <wsa@xxxxxxxxxxxxx>
No reactions on this, pity. Deferring.
Sorry, for delayed reply - I've had problems with my e-mail.
I've tested this patch on our TI K3.4 product kernel with additional
change below:
diff --git a/drivers/i2c/busses/i2c-gpio.c b/drivers/i2c/busses/i2c-gpio.c
index c0330a4..442101d 100644
--- a/drivers/i2c/busses/i2c-gpio.c
+++ b/drivers/i2c/busses/i2c-gpio.c
@@ -186,7 +186,7 @@ static int __devinit i2c_gpio_probe(struct
platform_device *pdev)
adap->owner = THIS_MODULE;
snprintf(adap->name, sizeof(adap->name), "i2c-gpio%d", pdev->id);
adap->algo_data = bit_data;
- adap->class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
+ adap->class = I2C_CLASS_HWMON | I2C_CLASS_SPD |
I2C_CLASS_DEPRECATED;
adap->dev.parent = &pdev->dev;
adap->dev.of_node = pdev->dev.of_node;
It works fine, in general - see my minor comment inline.
[ 0.662536] omap_i2c omap_i2c.2: bus 2 rev2.4.0 at 400 kHz
[ 0.662567] (null): This adapter will soon drop class based
instantiation of slaves
^^^^^ invalid adapter device name here
[ 0.662567] Please make sure all its I2C devices are instantiated by
other means.
[ 0.662567] Check 'Documentation/i2c/instantiating-devices' for details
Also tested on Linux master - OMAP4 SDP board.
In addition, I've found the following users of *i2c-gpio* (just FYI):
./arch/powerpc/boot/dts/wii.dts: compatible = "i2c-gpio";
./arch/mips/alchemy/board-gpr.c: .name = "i2c-gpio",
./arch/mips/ath79/mach-pb44.c: .name = "i2c-gpio",
./arch/avr32/boards/merisc/setup.c: .name = "i2c-gpio",
./arch/avr32/boards/atngw100/setup.c: .name = "i2c-gpio",
./arch/avr32/boards/hammerhead/setup.c: .name = "i2c-gpio",
./arch/avr32/boards/mimc200/setup.c: .name = "i2c-gpio",
./arch/blackfin/mach-bf533/boards/blackstamp.c: .name =
"i2c-gpio",
./arch/blackfin/mach-bf533/boards/ezkit.c: .name = "i2c-gpio",
./arch/blackfin/mach-bf533/boards/stamp.c: .name = "i2c-gpio",
./arch/blackfin/mach-bf561/boards/ezkit.c: .name = "i2c-gpio",
./arch/arm/mach-ep93xx/core.c: .name = "i2c-gpio",
./arch/arm/mach-shmobile/board-armadillo800eva.c: .name = "i2c-gpio",
./arch/arm/mach-pxa/viper.c: .name = "i2c-gpio",
./arch/arm/mach-pxa/viper.c: tpm_device =
platform_device_alloc("i2c-gpio", 2);
./arch/arm/mach-pxa/palmz72.c: .name = "i2c-gpio",
./arch/arm/boot/dts/at91sam9g45.dtsi: compatible = "i2c-gpio";
./arch/arm/boot/dts/at91sam9263.dtsi: compatible = "i2c-gpio";
./arch/arm/boot/dts/at91sam9x5.dtsi: compatible = "i2c-gpio";
./arch/arm/boot/dts/at91sam9x5.dtsi: compatible = "i2c-gpio";
./arch/arm/boot/dts/at91sam9x5.dtsi: compatible = "i2c-gpio";
./arch/arm/boot/dts/usb_a9g20-dab-mmx.dtsi: i2c-gpio@0 {
./arch/arm/boot/dts/ste-nomadik-stn8815.dtsi: compatible =
"i2c-gpio";
./arch/arm/boot/dts/ste-nomadik-stn8815.dtsi: compatible =
"i2c-gpio";
./arch/arm/boot/dts/ste-nomadik-stn8815.dtsi: compatible =
"i2c-gpio";
./arch/arm/boot/dts/at91sam9260.dtsi: compatible = "i2c-gpio";
./arch/arm/boot/dts/at91rm9200.dtsi: compatible = "i2c-gpio";
./arch/arm/boot/dts/at91sam9n12.dtsi: compatible = "i2c-gpio";
./arch/arm/mach-ks8695/board-acs5k.c: .name = "i2c-gpio",
./arch/arm/mach-s5pv210/mach-goni.c: .name = "i2c-gpio",
./arch/arm/mach-s5pv210/mach-goni.c: .name = "i2c-gpio",
./arch/arm/mach-s5pv210/mach-aquila.c: .name = "i2c-gpio",
./arch/arm/mach-s5pv210/mach-aquila.c: .name = "i2c-gpio",
./arch/arm/mach-sa1100/simpad.c: .name = "i2c-gpio",
./arch/arm/mach-exynos/mach-universal_c210.c: .name = "i2c-gpio",
./arch/arm/mach-exynos/mach-nuri.c: .name = "i2c-gpio",
./arch/arm/mach-at91/at91sam9263_devices.c: .name =
"i2c-gpio",
./arch/arm/mach-at91/at91sam9261_devices.c: .name =
"i2c-gpio",
./arch/arm/mach-at91/at91sam9g45_devices.c: .name =
"i2c-gpio",
./arch/arm/mach-at91/at91sam9g45_devices.c: .name =
"i2c-gpio",
./arch/arm/mach-at91/at91rm9200_devices.c: .name = "i2c-gpio",
./arch/arm/mach-at91/at91sam9260_devices.c: .name =
"i2c-gpio",
./arch/arm/mach-at91/at91sam9rl_devices.c: .name = "i2c-gpio",
./arch/arm/mach-imx/mach-cpuimx51sd.c: .name = "i2c-gpio",
./arch/arm/mach-ixp4xx/nslu2-setup.c: .name = "i2c-gpio",
./arch/arm/mach-ixp4xx/nas100d-setup.c: .name = "i2c-gpio",
./arch/arm/mach-ixp4xx/goramo_mlr.c: .name = "i2c-gpio",
./arch/arm/mach-ixp4xx/ixdp425-setup.c: .name = "i2c-gpio",
./arch/arm/mach-ixp4xx/fsg-setup.c: .name = "i2c-gpio",
./arch/arm/mach-ixp4xx/dsmg600-setup.c: .name = "i2c-gpio",
./arch/arm/mach-ixp4xx/avila-setup.c: .name = "i2c-gpio",
./drivers/mfd/sm501.c: pdev = sm501_create_subdev(sm, "i2c-gpio", 0,
- grygorii
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