As show in I2C specification:
- Standard-mode: the minimum HIGH period of the scl clock is 4.0us
the minimum LOW period of the scl clock is 4.7us
- Fast-mode: the minimum HIGH period of the scl clock is 0.6us
the minimum LOW period of the scl clock is 1.3us
I have measured i2c SCL waveforms in fast-mode by oscilloscope
on rk3288-pinky board. the LOW period of the scl clock is 1.3us.
It is so critical that we must adjust LOW division to increase
the LOW period of the scl clock.
Thanks Doug for the suggestion about division formulas.
Signed-off-by: Addy Ke <addy.ke@rock-chips.com>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Doug Anderson <dianders@chromium.org>
Reviewed-by: Max Schwarz <max.schwarz@online.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Pull i2c updates from Wolfram Sang:
"Highlights from the I2C subsystem for 3.18:
- new drivers for Axxia AM55xx, and Hisilicon hix5hd2 SoC.
- designware driver gained AMD support, exynos gained exynos7 support
The rest is usual driver stuff. Hopefully no lowlights this time"
* 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
i2c: i801: Add Device IDs for Intel Sunrise Point PCH
i2c: hix5hd2: add i2c controller driver
i2c-imx: Disable the clock on probe failure
i2c: designware: Add support for AMD I2C controller
i2c: designware: Rework probe() to get clock a bit later
i2c: designware: Default to fast mode in case of ACPI
i2c: axxia: Add I2C driver for AXM55xx
i2c: exynos: add support for HSI2C module on Exynos7
i2c: mxs: detect No Slave Ack on SELECT in PIO mode
i2c: cros_ec: Remove EC_I2C_FLAG_10BIT
i2c: cros-ec-tunnel: Add of match table
i2c: rcar: remove sign-compare flaw
i2c: ismt: Use minimum descriptor size
i2c: imx: Add arbitration lost check
i2c: rk3x: Remove unlikely() annotations
i2c: rcar: check for no IRQ in rcar_i2c_irq()
i2c: rcar: make rcar_i2c_prepare_msg() *void*
i2c: rcar: simplify check for last message
i2c: designware: add support of platform data to set I2C mode
i2c: designware: add support of I2C standard mode
i2cdetect -q was broken (everything was a false positive, and no transfers were
actually being sent over i2c). The way it works is by sending a 0 length write
request and checking for NACK. This patch fixes the 0 length writes and actually
sends them.
Reported-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Alexandru M Stan <amstan@chromium.org>
Tested-by: Doug Anderson <dianders@chromium.org>
Tested-by: Max Schwarz <max.schwarz@online.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org
Having a transfer more than 32 bits is not all that unlikely. Remove
the annotation.
The unlikely in the IRQ handler can't gain us much. It's not in a
loop, so at most it would save 1 instruction per IRQ, which isn't
much. In fact on the compiler I tested it produced the exact same
code. Remove it too.
Suggested-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
I2C_CLKDIV register descripted in the previous version of
RK3x chip manual is incorrect. Plus 1 is required.
The correct formula:
- T(SCL_HIGH) = T(PCLK) * (CLKDIVH + 1) * 8
- T(SCL_LOW) = T(PCLK) * (CLKDIVL + 1) * 8
- (SCL Divsor) = 8 * ((CLKDIVL + 1) + (CLKDIVH + 1))
- SCL = PCLK / (CLK Divsor)
It will be updated to the latest version of chip manual.
Signed-off-by: Addy Ke <addy.ke@rock-chips.com>
Reviewed-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org
In rk3x SOC, the I2C controller can receive/transmit up to 32 bytes data
in one chunk, so the size of data to be write/read to/from TXDATAx/RXDATAx
must be less than or equal 32 bytes at a time.
Tested on rk3288-pinky board, elan receive 158 bytes data.
Signed-off-by: Addy Ke <addy.ke@rock-chips.com>
Acked-by: Max Schwarz <max.schwarz@online.de>
Reviewed-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org
If slave holds scl, I2C_IPD[7] will be set 1 by controller
for debugging. Driver must ignore it.
[ 5.752391] rk3x-i2c ff160000.i2c: unexpected irq in WRITE: 0x80
[ 5.939027] rk3x-i2c ff160000.i2c: timeout, ipd: 0x80, state: 4
Signed-off-by: Addy Ke <addy.ke@rock-chips.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org
drivers/i2c/busses/i2c-rk3x.c:610:69-70: rk3x_i2c_match is not NULL terminated at line 610
Make sure of_device_id tables are NULL terminated
Generated by: /kbuild/src/linux/scripts/coccinelle/misc/of_table.cocci
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Driver for the native I2C adapter found in Rockchip RK3xxx SoCs.
Configuration is only possible through devicetree. The driver is
interrupt driven and supports the I2C_M_IGNORE_NAK mangling bit.
Signed-off-by: Max Schwarz <max.schwarz@online.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
addy ke