There's no reason to require callers to cast their data to uint8_t *
when the data might e.g. originate in a packed struct or some other
data type. Instead, be nice to callers and let them use any pointer
they want. Additionally, declare the TX buffer as a const pointer so
unnecessary typecasts aren't needed for that either (if the data
originates in a const location).
Change-Id: I1482ca4e350b5a7fbda6871ed9f54f255af3aa9e
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Though it's an ARC core, Quark SE SS does not follow the same registers
mapping as the official DesignWare document. Some parts are common, some
not.
Instead of bloating spi_dw.c with a lot of #ifdef or rewriting a whole
new driver though the logic is 99% the same, it's then better to:
- centralize common macros and definitions into spi_dw.h
- have a specific spi_dw_quark_se_ss_reg.h for register map, clock
gating and register helpers dedicated to Quark SE SS.
- have a spi_dw_regs.h for the common case, i.e. not Quark SE SS.
GPIO CS emulation and interrupt masking ends up then in spi_dw.h.
Clock gating is specific thus found in respective *_regs.h header.
Adding proper interrupt masks to quark_se_ss soc.h file as well.
One of the main difference is also the interrupt management: through one
line or multiple lines (one for each interrupt: rx, tx and error). On
Quark SE Sensor Sub-System it has been set to use multiple lines, thus
introducing relevant Kconfig options and managing those when configuring
the IRQs.
Quark SE SS SPI controller is also working on a lower level, i.e. it
requires a tiny bit more logic from the driver. Main example is the data
register which needs to be told what is happening from the driver.
Taking the opportunity to fix minor logic issues:
- ICR register should be cleared by reading, only on error in the ISR
handler, but it does not harm doing it anyway and because Quark SE SS
requires to clear up interrupt as soon as they have been handled,
introducing a clear_interrupts() function called at the and of the ISR
handler.
- TXFTLR should be set after each spi_transceive() since last pull_data
might set it to 0.
- Enable the clock (i.e. open the clock gate) at initialization.
- No need to mask interrupts at spi_configure() since these are already
masked at initialization and at the end of a transaction.
- Let's use BIT() macro when relevant.
Change-Id: I24344aaf8bff3390383a84436f516951c1a2d2a4
Signed-off-by: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>
Adds extern "C" { } blocks to header files so that they can be
safely used by C++ source files.
Change-Id: Ia4db0c36a5dac5d3de351184a297d2af0df64532
Signed-off-by: Peter Mitsis <peter.mitsis@windriver.com>
It might be necessary to emulate CS through a GPIO pin depending on
these 2 conditions:
- the controller's CS pin is not wired, and thus a GPIO pin is the only
option
- The controller is unstable at a certain frequency and cannot set/unset
CS reliably. This is actually a possible issue on DesignWare's SPI
controller in Quark SE or Quarks D2000 where it has been found
unstable at 1Mhz and above.
Change-Id: Ib6a06577906c005ddd347070d476a367a9c3da8a
Signed-off-by: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>
- Refine how DFS is calulated now that it is strictely used to
manipulate buffer lengths.
- Fix threshold limit
- Tune RX threshold relevantly (reduce it if rx_len is lower than actual)
- Don't push more than available left space in FIFO
- Tune the private structure to lower memory space occupation
Change-Id: I65b1b48b996b2104cebcb24cc366fb4dcbf7d53b
Signed-off-by: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>
IMR and ISR bits are same, but it stil better to differentiate them
properly. Also fixing naming where all ISR ends with an 'S'.
Change-Id: I2fc1e1d8d2743c3d98f5da40a5f4720a85c4f9a7
Signed-off-by: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>
Registers offsets are hopefully all the same, but size differs.
On x86, thus 32bits support, CTRL0 or DR for instance are 32 bits r/w.
And DFS on 32 bits support is placed differently as well.
Change-Id: I5115d5c3c9bba71ece4a6f4a1d3d2fdc203c8da1
Signed-off-by: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>
Only 8 bit frames were supported. Added support for bigger data frames
which can go up to 32 bits (on 32bits version of the controller, 16 bits
otherwise). Store the frame size in bytes during configure, and use it
during pull/push to read/write correct frame size.
Change-Id: Iae8c55442e0a205403aa3febd1811b36aaf4c5b6
Signed-off-by: Ramesh Thomas <ramesh.thomas@intel.com>
Signed-off-by: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>
Johan Hedberg