[PATCH 0/4] Fix the i2c/clk bug of stm32 mcu platform

[dillon . minfei]

From: Dillon Min <dillon.minfei@xxxxxxxxx>

This seriese fix three i2c/clk bug for stm32 f4/f7
- kernel runing in sdram, i2c driver get data timeout
- ltdc clk turn off after kernel console active
- kernel hang in set ltdc clock rate

clk bug found on stm32f429/f469-disco board

Hi Patrice:
below is the guide to verify the patch:

setup test env with following files(link at below 'files link'):
[1] u-boot-dtb.bin
[2] rootfs zip file (used in kernel initramfs)
[3] u-boot's mkimage to create itb file
[4] kernel config file
[5] my itb with-or-without i2c patch

This patch based on kernel commit:
88b06399c9c766c283e070b022b5ceafa4f63f19

Note:
panel-ilitek-ili9341.c is the driver which was submitted last year, but not
get accepted. it's used to setup touch screen calibration, then test i2c.

create itb file(please correct path of 'data'):
./mkimage -f stm32.its stm32.itb

HW setup:
console:
       PA9, PA10
       usart0
       serial@40011000
       115200 8n1

-- flash u-boot.bin to stm32f429-disco on PC
$ sudo openocd -f board/stm32f429discovery.cfg -c \
  '{PATH-TO-YOUR-UBOOT}/u-boot-dtb.bin 0x08000000 exit reset'

-- setup kernel load bootargs at u-boot
U-Boot > setenv bootargs 'console=tty0 console=ttySTM0,115200
                    root=/dev/ram rdinit=/linuxrc loglevel=8 fbcon=rotate:2'
U-Boot > loady;bootm
(download stm32.dtb or your kernel with itb format, or download zImage, dtb)

-- setup ts_calibrate running env on stm32f429-disco
/ # export TSLIB_CONFFILE=/etc/ts.conf
/ # export TSLIB_TSDEVICE=/dev/input/event0
/ # export TSLIB_CONSOLEDEVICE=none
/ # export TSLIB_FBDEVICE=/dev/fb0

-- clear screen
/ # ./fb

-- run ts_calibrate 
/ # ts_calibrate
(you can calibrate touchscreen now, and get below errors)

[  113.942087] stmpe-i2c0-0041: failed to read regs 0x52: -110
[  114.063598] stmpe-i2c 0-0041: failed to read reg 0x4b: -16
[  114.185629] stmpe-i2c 0-0041: failed to read reg 0x40: -16
[  114.307257] stmpe-i2c 0-0041: failed to write reg 0xb: -16

...
with i2c patch applied, you will find below logs:

RAW---------------------> 3164 908 183 118.110884
TS_READ_RAW----> x = 3164, y =908, pressure = 183
RAW---------------------> 3166 922 126 118.138946
TS_READ_RAW----> x = 3166, y = 922, pressure = 126
....

files link:
https://drive.google.com/drive/folders/1qNbjChcB6UGtKzne2F5x9_WG_sZFyo3o?usp=sharing




Dillon Min (4):
  drm/panel: Add ilitek ili9341 panel driver
  i2c: stm32f4: Fix stmpe811 get xyz data timeout issue
  clk: stm32: Fix stm32f429's ltdc driver hang in set clock rate
  clk: stm32: Fix ltdc's clock turn off by clk_disable_unused() after
    kernel startup

 drivers/clk/clk-stm32f4.c                    |   10 +-
 drivers/gpu/drm/panel/Kconfig                |   12 +
 drivers/gpu/drm/panel/Makefile               |    1 +
 drivers/gpu/drm/panel/panel-ilitek-ili9341.c | 1285 ++++++++++++++++++++++++++
 drivers/i2c/busses/i2c-stm32f4.c             |   12 +-
 5 files changed, 1310 insertions(+), 10 deletions(-)
 create mode 100755 drivers/gpu/drm/panel/panel-ilitek-ili9341.c

-- 
2.7.4