Commit graph

6 commits

Author SHA1 Message Date
Peng Fan
e1bed80272 dm: i2c: mxc_i2c: implement i2c_idle_bus
Implement i2c_idle_bus in driver, then setup_i2c can
be dropped for boards which enable DM_I2C/DM_GPIO/PINCTRL.
The i2c_idle_bus force bus idle flow follows setup_i2c in
arch/arm/imx-common/i2c-mxv7.c

This patch is an implementation following linux kernel patch:
"
commit 1c4b6c3bcf30d0804db0d0647d8ebeb862c6f7e5
Author: Gao Pan <b54642@freescale.com>
Date:   Fri Oct 23 20:28:54 2015 +0800

    i2c: imx: implement bus recovery

    Implement bus recovery methods for i2c-imx so we can recover from
    situations where SCL/SDA are stuck low.

    Once i2c bus SCL/SDA are stuck low during transfer, config the i2c
    pinctrl to gpio mode by calling pinctrl sleep set function, and then
    use GPIO to emulate the i2c protocol to send nine dummy clock to recover
    i2c device. After recovery, set i2c pinctrl to default group setting.
"

See Documentation/devicetree/bindings/i2c/i2c-imx.txt for detailed
description.
1. Introuduce scl_gpio/sda_gpio/bus in mxc_i2c_bus.
2. Discard the __weak attribute for i2c_idle_bus and implement it,
   since we have pinctrl driver/driver model gpio driver. We can
   use device tree, but not let board code to do this.
3. gpio state for mxc_i2c is not a must, but it is recommended. If
   there is no gpio state, driver will give tips, but not fail.
4. The i2c controller was first probed, default pinctrl state will
   be used, so when need to use gpio function, need to do
   "pinctrl_select_state(dev, "gpio")" and after force bus idle,
   need to switch back "pinctrl_select_state(dev, "default")".

This is example about how to use the gpio force bus
idle function:
"
 &i2c1 {
 	clock-frequency = <100000>;
	pinctrl-names = "default", "gpio";
 	pinctrl-0 = <&pinctrl_i2c1>;
	pinctrl-1 = <&pinctrl_i2c1_gpio>;
	scl-gpios = <&gpio1 28 GPIO_ACTIVE_HIGH>;
	sda-gpios = <&gpio1 29 GPIO_ACTIVE_HIGH>;
	status = "okay";
	[....]
 };

[.....]

	pinctrl_i2c1_gpio: i2c1grp_gpio {
		fsl,pins = <
			MX6UL_PAD_UART4_TX_DATA__GPIO1_IO28 0x1b8b0
			MX6UL_PAD_UART4_RX_DATA__GPIO1_IO29 0x1b8b0
		>;
	};
"

Signed-off-by: Peng Fan <van.freenix@gmail.com>
Cc: Albert Aribaud <albert.u.boot@aribaud.net>
Cc: Stefano Babic <sbabic@denx.de>
Cc: Heiko Schocher <hs@denx.de>
Cc: Simon Glass <sjg@chromium.org>
Cc: York Sun <york.sun@nxp.com>
2016-03-28 09:22:58 +02:00
Peng Fan
71204e95ce i2c: mxc: refactor i2c driver and support dm
1. Introduce a new structure `struct mxc_i2c_bus`, this structure will
   used for non-DM and DM.
2. Remove `struct mxc_i2c_regs` structure, but use register offset to access
   registers based on `base` entry of `struct mxc_i2c_bus`.
3. Remove most `#ifdef I2C_QUIRK_REG`. Using driver_data to contain platform
   flags. A new flag is introduced, I2C_QUIRK_FLAG.
4. Most functions use `struct mxc_i2c_bus` as one of the parameters.
   Make most functions common to DM and non-DM, try to avoid duplicated code.
5. Support DM, but pinctrl is not included. Pinmux setting is still set
   by setup_i2c, but we do not need bus_i2c_init for DM.
6. struct i2c_parms and struct sram_data are removed.
7. Remove bus_i2c_read bus_i2c_write prototype in header file. The frist
   paramter of bus_i2c_init is modified to i2c index. Add new prototype
   i2c_idle_bus and force_bus_idle. Since bus_i2c_init is not good for
   DM I2C and pinctrl is missed, we use a weak function for i2c_idle_bus.
   Board file take the responsibility to implement this function, like this:
   "
   int i2c_idle_bus(struct mxc_i2c_bus *i2c_bus)
   {
	   if (i2c_bus->index == 0)
		   force_bus_idle(i2c_pads_info0);
	   else if (i2c_bus->index == 1)
		   force_bus_idle(i2c_pads_info1);
	   else
		   xxxxxx
   }
   "
8. Introduce a weak function, enable_i2c_clk
9. Tested on an i.MX7 platform. Log info:
 => dm tree
 Class       Probed   Name
 ----------------------------------------
 root        [ + ]    root_driver
 simple_bus  [   ]    |-- soc
 simple_bus  [   ]    |   |-- aips-bus@30000000
 simple_bus  [   ]    |   |   |-- anatop@30360000
 simple_bus  [   ]    |   |   `-- snvs@30370000
 simple_bus  [   ]    |   |-- aips-bus@30400000
 simple_bus  [   ]    |   `-- aips-bus@30800000
 i2c         [   ]    |       |-- i2c@30a20000
 i2c         [   ]    |       `-- i2c@30a40000
 simple_bus  [   ]    `-- regulators
 => i2c dev 0
 Setting bus to 0
 => i2c probe
 Valid chip addresses: 08 50
 => i2c md 8 31
 0031: 08 08 08 08 08 08 08 08 08 08 08 08 08 08 08 08

Signed-off-by: Peng Fan <Peng.Fan@freescale.com>
Acked-by: Simon Glass <sjg@chromium.org>
2015-05-14 18:49:36 -06:00
Simon Glass
edbf8b4f8c imx: Add error checking to setup_i2c()
Since this function can fail, check its return value.

Signed-off-by: Simon Glass <sjg@chromium.org>
Tested-by: Nikita Kiryanov <nikita@compulab.co.il>
2014-10-22 10:36:55 -06:00
Nikita Kiryanov
c6c2492ad8 i2c: imx: add macros to setup pads for multiple SoC types
Add macro which defines i2c_pads_info structs for multiple SoC types,
and a macro which selects the appropriate struct based on CPU type,
thus eliminating the need to manage multiple i2c pad configurations
manually when supporting multiple SoC types.

Cc: Stefano Babic <sbabic@denx.de>
Cc: Tim Harvey <tharvey@gateworks.com>
Acked-by: Tim Harvey <tharvey@gateworks.com>
Signed-off-by: Nikita Kiryanov <nikita@compulab.co.il>
2014-09-09 15:32:32 +02:00
Wolfgang Denk
1a4596601f Add GPL-2.0+ SPDX-License-Identifier to source files
Signed-off-by: Wolfgang Denk <wd@denx.de>
[trini: Fixup common/cmd_io.c]
Signed-off-by: Tom Rini <trini@ti.com>
2013-07-24 09:44:38 -04:00
Troy Kisky
cc54a0f7cc imx-common: add i2c.c for bus recovery support
Signed-off-by: Troy Kisky <troy.kisky@boundarydevices.com>
2012-07-31 08:00:57 +02:00