On Sun, Jul 01, 2018 at 10:52:59PM +0530, Manivannan Sadhasivam wrote: > This patchset adds I2C controller support for Actions Semiconductor S900 SoC. > This driver has been structured in a way such that there will be only > one controller driver for the whole Owl family series (S500, S700 and > S900 SoCs). > > There are 6 I2C controllers with separate memory mapped register space. > The I2C controller can handle atmost two messages concatenated by a > repeated start via its internal address feature. Hence the driver > uses this feature for messages of length greater than 1. In those cases, > the first message of the combined message should be a `write` with maximum > message length 6 and the second message's maximum length should be 240 bytes. > > As far as the bus speed is concerned, this driver only supports > Standard (100KHz) and High speed (400KHz) for now. > > The pinctrl definitions are only available for I2C0, I2C1 and I2C2. > With the mux option available only for I2C0. > > For Bubblegum-96 board utilizing the S900 SoC, only I2C1 and I2C2 which > are exposed on the Low speed expansion connector are enabled. > > This series depends on the pinctrl patch [1] is still not merged by the > platform maintainer Andreas but it has been reviewed by the pinctrl maintainer > Linus Walleij. For the reference, I have queued up all reviewed dts patches > in my tree [2] from which Andreas is picking them for 4.19. > > For this series, since the dts patches will go through the ARM SoC tree, > Andreas will pick it up once it is reviewed. > > Thanks, > Mani > > [1] https://patchwork.kernel.org/patch/10322937/ > [2] > https://git.linaro.org/people/manivannan.sadhasivam/linux.git/log/?h=s900-for-next >
Hi Andy, Peter, Just a gentle ping on this v4! Thanks, Mani > Changes in v4: > > As per Andy and Peter review: > > * Used spinlock for accessing most of the register access (only parts > involved sleep/long-busy-wait has been excluded) > * Removed returning 0 and added -ENXIO if the msg_ptr not equals to > message length > * Added DIV_ROUND_UP for setting clock frequency > * Changed one non-atomic mdelay instance to usleep_range > * Moved pinctrl definition patch before dts patch > * Fixed the driver to support only 100KHz and 400KHz frequencies > > Changes in v3: > > As per Peter, Andy and Andreas review: > > * Removed owl_i2c_reset function from interrupt handler since it > involves the use of delays. > * Fixed the return path in owl_i2c_master_xfer and added a note > * Changed "base" parameter to "reg" in owl_i2c_update_reg for better > understandability > * Ordered the includes in alphabetical order > * Small changes to defines and added comma at the end of struct members > * Removed rendundant 0 assignment in owl_i2c_master_xfer > * Changed all OWL naming convention to Owl and also changed Actions Semi > naming to Actions Semiconductor > > Changes in v2: > > As per Andy's review: > * Modified infinite loops to fixed number of retries > * Used i2c_8bit_addr_from_msg for constructing the slave address > * Removed unnecessary parenthesis around defines > * Modified certain dev_warn to dev_dbg > * Modified the error handling to more generic pattern > > * Fixed the return value in owl_i2c_master_xfer > * Added MAINTAINERS patch for I2C driver and its binding > > Manivannan Sadhasivam (6): > dt-bindings: i2c: Add binding for Actions Semiconductor Owl I2C > controller > arm64: dts: actions: Add pinctrl definition for S900 I2C controller > arm64: dts: actions: Add Actions Semiconductor S900 I2C controller > nodes > arm64: dts: actions: Enable I2C1 and I2C2 in Bubblegum-96 board > i2c: Add Actions Semiconductor Owl family S900 I2C driver > MAINTAINERS: Add entry for Actions Semiconductor Owl I2C driver > > .../devicetree/bindings/i2c/i2c-owl.txt | 27 + > MAINTAINERS | 2 + > .../dts/actions/s900-bubblegum-96-pins.dtsi | 29 + > .../boot/dts/actions/s900-bubblegum-96.dts | 11 + > arch/arm64/boot/dts/actions/s900.dtsi | 60 +++ > drivers/i2c/busses/Kconfig | 7 + > drivers/i2c/busses/Makefile | 1 + > drivers/i2c/busses/i2c-owl.c | 504 ++++++++++++++++++ > 8 files changed, 641 insertions(+) > create mode 100644 Documentation/devicetree/bindings/i2c/i2c-owl.txt > create mode 100644 arch/arm64/boot/dts/actions/s900-bubblegum-96-pins.dtsi > create mode 100644 drivers/i2c/busses/i2c-owl.c > > -- > 2.17.1 >
