summaryrefslogtreecommitdiff
path: root/drivers/spi/spi-geni-qcom.c
AgeCommit message (Collapse)Author
2020-06-24spi: spi-geni-qcom: Add interconnect supportAkash Asthana
Get the interconnect paths for SPI based Serial Engine device and vote according to the current bus speed of the driver. Acked-by: Mark Brown <broonie@kernel.org> Signed-off-by: Akash Asthana <akashast@codeaurora.org> Link: https://lore.kernel.org/r/1592908737-7068-7-git-send-email-akashast@codeaurora.org Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
2020-06-24spi: spi-geni-qcom: Combine the clock setting codeDouglas Anderson
There is code for adjusting the clock both in setup_fifo_params() (called from prepare_message()) and in setup_fifo_xfer() (called from transfer_one()). The code is the same. Abstract it out to a shared function. This is a no-op cleanup patch. The only change is to the error string if we fail to set the clock. Since the two paths has marginally different error messages I picked the clean one. Acked-by: Mark Brown <broonie@kernel.org> Signed-off-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Akash Asthana <akashast@codeaurora.org> Link: https://lore.kernel.org/r/1592908737-7068-6-git-send-email-akashast@codeaurora.org Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
2020-06-22spi: spi-geni-qcom: Don't set {tx,rx}_rem_bytes unnecessarilyStephen Boyd
We only need to test for these counters being non-zero when we see the end of a transfer. If we're doing a CS change then they will already be zero. This implies that we don't need to set these to 0 if we're cancelling an in flight transfer too, because we only care to test these counters when the 'DONE' bit is set in the hardware and we've set them to non-zero for a transfer. This is a non-functional change, just cleanup to consolidate code. Signed-off-by: Stephen Boyd <swboyd@chromium.org> Reviewed-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20200620022233.64716-3-swboyd@chromium.org Signed-off-by: Mark Brown <broonie@kernel.org>
2020-06-22spi: spi-geni-qcom: Simplify setup_fifo_xfer()Stephen Boyd
The definition of SPI_FULL_DUPLEX (3) is really SPI_TX_ONLY (1) ORed with SPI_RX_ONLY (2). Let's drop the define and simplify the code here a bit by collapsing the setting of 'm_cmd' into conditions that are the same. This is a non-functional change, just cleanup to consolidate code. Signed-off-by: Stephen Boyd <swboyd@chromium.org> Reviewed-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20200620022233.64716-2-swboyd@chromium.org Signed-off-by: Mark Brown <broonie@kernel.org>
2020-06-19spi: spi-geni-qcom: Don't keep a local state variableDouglas Anderson
The variable "cur_mcmd" kept track of our current state (idle, xfer, cs, cancel). We don't really need it, so get rid of it. Instead: * Use separate condition variables for "chip select done", "cancel done", and "abort done". This is important so that if a "done" comes through (perhaps some previous interrupt finally came through) it can't confuse the cancel/abort function. * Use the "done" interrupt only for when a chip select or transfer is done and we can tell the difference by looking at whether "cur_xfer" is NULL. This is mostly a no-op change. However, it is possible it could fix an issue where a super delayed interrupt for a cancel command could have confused our waiting for an abort command. Signed-off-by: Douglas Anderson <dianders@chromium.org> Reviewed-by: Stephen Boyd <swboyd@chromium.org> Link: https://lore.kernel.org/r/20200618080459.v4.5.Ib1e6855405fc9c99916ab7c7dee84d73a8bf3d68@changeid Signed-off-by: Mark Brown <broonie@kernel.org>
2020-06-19spi: spi-geni-qcom: Actually use our FIFODouglas Anderson
The geni hardware has a FIFO that can hold up to 64 bytes (it has 16 entries that can hold 4 bytes each), at least on the two SoCs I tested (sdm845 and sc7180). We configured our RX Watermark to 0, which basically meant we got an interrupt as soon as the first 4 bytes showed up in the FIFO. Tracing the IRQ handler showed that we often only read 4 or 8 bytes per IRQ handler. I tried setting the RX Watermark to "fifo size - 2" but that just got me a bunch of overrun errors reported. Setting it to "fifo size - 3" seemed to work great, though. This made me worried that we'd start getting overruns if we had long interrupt latency, but that doesn't appear to be the case and delays inserted in the IRQ handler while using "fifo size - 3" didn't cause any errors. Presumably there is some interaction with the poorly-documented RFR (ready for receive) level means that "fifo size - 3" is the max. We are the SPI master, so it makes sense that there would be no problems with overruns, the master should just stop clocking. Despite "fifo size - 3" working, I chose "fifo size / 2" (8 entries = 32 bytes) which gives us a little extra time to get to the interrupt handler and should reduce dead time on the SPI wires. With this setting, I often saw the IRQ handler handle 40 bytes but sometimes up to 56 if we had bad interrupt latency. Testing by running "flashrom -p ec -r" on a Chromebook saw interrupts from the SPI driver cut roughly in half. Time was roughly the same. Fixes: 561de45f72bd ("spi: spi-geni-qcom: Add SPI driver support for GENI based QUP") Signed-off-by: Douglas Anderson <dianders@chromium.org> Reviewed-by: Stephen Boyd <swboyd@chromium.org> Link: https://lore.kernel.org/r/20200618080459.v4.4.I988281f7c6ee0ed00325559bfce7539f403da69e@changeid Signed-off-by: Mark Brown <broonie@kernel.org>
2020-06-19spi: spi-geni-qcom: Check for error IRQsDouglas Anderson
>From reading the #defines it seems like we should shout if we ever see one of these error bits. Let's do so. This doesn't do anything functional except print a yell in the log if the error bits are seen. Signed-off-by: Douglas Anderson <dianders@chromium.org> Reviewed-by: Stephen Boyd <swboyd@chromium.org> Link: https://lore.kernel.org/r/20200618080459.v4.3.Id8bebdbdb4d2ed9468634343a7e6207d6cffff8a@changeid Signed-off-by: Mark Brown <broonie@kernel.org>
2020-06-19spi: spi-geni-qcom: Mo' betta lockingDouglas Anderson
If you added a bit of a delay (like a trace_printk) into the ISR for the spi-geni-qcom driver, you would suddenly start seeing some errors spit out. The problem was that, though the ISR itself held a lock, other parts of the driver didn't always grab the lock. One example race was this: CPU0 CPU1 ---- ---- spi_geni_set_cs() mas->cur_mcmd = CMD_CS; geni_se_setup_m_cmd(...) wait_for_completion_timeout(&xfer_done); <INTERRUPT> geni_spi_isr() complete(&xfer_done); <wakeup> pm_runtime_put(mas->dev); ... // back to SPI core spi_geni_transfer_one() setup_fifo_xfer() mas->cur_mcmd = CMD_XFER; mas->cur_cmd = CMD_NONE; // bad! return IRQ_HANDLED; Let's fix this. Before we start messing with hardware, we'll grab the lock to make sure that the IRQ handler from some previous command has really finished. We don't need to hold the lock unless we're in a state where more interrupts can come in, but we at least need to make sure the previous IRQ is done. This lock is used exclusively to prevent the IRQ handler and non-IRQ from stomping on each other. The SPI core handles all other mutual exclusion. As part of this, we change the way that the IRQ handler detects spurious interrupts. Previously we checked for our state variable being set to IRQ_NONE, but that was done outside the spinlock. We could move it into the spinlock, but instead let's just change it to look for the lack of any IRQ status bits being set. This can be done outside the lock--the hardware certainly isn't grabbing or looking at the spinlock when it updates its status register. It's possible that this will fix real (but very rare) errors seen in the field that look like: irq ...: nobody cared (try booting with the "irqpoll" option) NOTE: an alternate strategy considered here was to always make the complete() / spi_finalize_current_transfer() the very last thing in our IRQ handler. With such a change you could consider that we could be "lockless". In that case, though, we'd have to be very careful w/ memory barriers so we made sure we didn't have any bugs with weakly ordered memory. Using spinlocks makes the driver much easier to understand. Fixes: 561de45f72bd ("spi: spi-geni-qcom: Add SPI driver support for GENI based QUP") Signed-off-by: Douglas Anderson <dianders@chromium.org> Reviewed-by: Stephen Boyd <swboyd@chromium.org> Link: https://lore.kernel.org/r/20200618080459.v4.2.I752ebdcfd5e8bf0de06d66e767b8974932b3620e@changeid Signed-off-by: Mark Brown <broonie@kernel.org>
2020-06-18spi: spi-geni-qcom: No need for irqsave variant of spinlock callsDouglas Anderson
The driver locks its locks in two places. In the first usage of the lock the function doing the locking already has a sleeping call and thus we know we can't be called from interrupt context. That means we can use the "spin_lock_irq" variant of the function. In the second usage of the lock the function is the interrupt handler and we know interrupt handlers are called with interrupts disabled. That means we can use the "spin_lock" variant of the function. This patch is expected to be a no-op and is just a cleanup / slight optimization. Signed-off-by: Douglas Anderson <dianders@chromium.org> Reviewed-by: Stephen Boyd <swboyd@chromium.org> Link: https://lore.kernel.org/r/20200616034044.v3.1.Ic50cccdf27d42420a63485082f8b5bf86ed1a2b6@changeid Signed-off-by: Mark Brown <broonie@kernel.org>
2020-02-11spi: spi-geni-qcom: Drop of.h includeStephen Boyd
This driver doesn't call any DT functions like of_get_property(). Remove the of.h include as it isn't used. Cc: Girish Mahadevan <girishm@codeaurora.org> Cc: Dilip Kota <dkota@codeaurora.org> Cc: Alok Chauhan <alokc@codeaurora.org> Cc: Douglas Anderson <dianders@chromium.org> Signed-off-by: Stephen Boyd <swboyd@chromium.org> Reviewed-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20200204191206.97036-4-swboyd@chromium.org Signed-off-by: Mark Brown <broonie@kernel.org>
2020-02-11spi: spi-geni-qcom: Grow a dev pointer to simplify codeStephen Boyd
Some lines are long here. Use a struct dev pointer to shorten lines and simplify code. The clk_get() call can fail because of EPROBE_DEFER problems too, so just remove the error print message because it isn't useful. Cc: Girish Mahadevan <girishm@codeaurora.org> Cc: Dilip Kota <dkota@codeaurora.org> Cc: Alok Chauhan <alokc@codeaurora.org> Cc: Douglas Anderson <dianders@chromium.org> Signed-off-by: Stephen Boyd <swboyd@chromium.org> Reviewed-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20200204191206.97036-3-swboyd@chromium.org Signed-off-by: Mark Brown <broonie@kernel.org>
2020-02-11spi: spi-geni-qcom: Let firmware specify irq trigger flagsStephen Boyd
We don't need to force IRQF_TRIGGER_HIGH here as the DT or ACPI tables should take care of this for us. Just use 0 instead so that we use the flags from the firmware. Cc: Girish Mahadevan <girishm@codeaurora.org> Cc: Dilip Kota <dkota@codeaurora.org> Cc: Alok Chauhan <alokc@codeaurora.org> Cc: Douglas Anderson <dianders@chromium.org> Signed-off-by: Stephen Boyd <swboyd@chromium.org> Reviewed-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20200204191206.97036-2-swboyd@chromium.org Signed-off-by: Mark Brown <broonie@kernel.org>
2019-09-04spi: spi-geni-qcom: use devm_platform_ioremap_resource() to simplify codeYueHaibing
Use devm_platform_ioremap_resource() to simplify the code a bit. This is detected by coccinelle. Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: YueHaibing <yuehaibing@huawei.com> Link: https://lore.kernel.org/r/20190904135918.25352-14-yuehaibing@huawei.com Signed-off-by: Mark Brown <broonie@kernel.org>
2019-08-02spi: Remove dev_err() usage after platform_get_irq()Stephen Boyd
We don't need dev_err() messages when platform_get_irq() fails now that platform_get_irq() prints an error message itself when something goes wrong. Let's remove these prints with a simple semantic patch. // <smpl> @@ expression ret; struct platform_device *E; @@ ret = ( platform_get_irq(E, ...) | platform_get_irq_byname(E, ...) ); if ( \( ret < 0 \| ret <= 0 \) ) { ( -if (ret != -EPROBE_DEFER) -{ ... -dev_err(...); -... } | ... -dev_err(...); ) ... } // </smpl> While we're here, remove braces on if statements that only have one statement (manually). Cc: Mark Brown <broonie@kernel.org> Cc: linux-spi@vger.kernel.org Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Stephen Boyd <swboyd@chromium.org> Link: https://lore.kernel.org/r/20190730181557.90391-42-swboyd@chromium.org Signed-off-by: Mark Brown <broonie@kernel.org>
2019-01-14spi: spi-geni-qcom: Get rid of forward declarationStephen Boyd
We don't need this forward declaration. Move the function to where it needed so we can drop it and shave some lines of code. CC: Girish Mahadevan <girishm@codeaurora.org> CC: Dilip Kota <dkota@codeaurora.org> CC: Alok Chauhan <alokc@codeaurora.org> Cc: Douglas Anderson <dianders@chromium.org> Signed-off-by: Stephen Boyd <swboyd@chromium.org> Signed-off-by: Mark Brown <broonie@kernel.org>
2019-01-14spi: spi-geni-qcom: Don't initialize completion for normal messageStephen Boyd
We only use this completion when we're doing something that isn't a message transfer. For example, changing CS or aborting/canceling a command. All of those situations properly reinitialize the completion before sending the GENI the special command to change CS or cancel, etc. Given that, let's remove the initialization here. Cc: Girish Mahadevan <girishm@codeaurora.org> Cc: Dilip Kota <dkota@codeaurora.org> Cc: Alok Chauhan <alokc@codeaurora.org> Cc: Douglas Anderson <dianders@chromium.org> Signed-off-by: Stephen Boyd <swboyd@chromium.org> Signed-off-by: Mark Brown <broonie@kernel.org>
2018-11-05spi: spi-geni-qcom: Simplify probe functionAlok Chauhan
Re-arrange existing APIs in probe function to avoid using goto and remove redundant variables. Signed-off-by: Alok Chauhan <alokc@codeaurora.org> Reviewed-by: Douglas Anderson <dianders@chromium.org> Reviewed-by: Stephen Boyd <swboyd@chromium.org> Signed-off-by: Mark Brown <broonie@kernel.org>
2018-11-05spi: spi-geni-qcom: fix nitpicksAlok Chauhan
fixed the nitpicks. Signed-off-by: Alok Chauhan <alokc@codeaurora.org> Reviewed-by: Douglas Anderson <dianders@chromium.org> Reviewed-by: Stephen Boyd <swboyd@chromium.org> Signed-off-by: Mark Brown <broonie@kernel.org>
2018-10-11spi: spi-geni-qcom: Add SPI driver support for GENI based QUPGirish Mahadevan
This driver supports GENI based SPI Controller in the Qualcomm SOCs. The Qualcomm Generic Interface (GENI) is a programmable module supporting a wide range of serial interfaces including SPI. This driver supports SPI operations using FIFO mode of transfer. Signed-off-by: Girish Mahadevan <girishm@codeaurora.org> Signed-off-by: Dilip Kota <dkota@codeaurora.org> Signed-off-by: Alok Chauhan <alokc@codeaurora.org> Reviewed-by: Douglas Anderson <dianders@chromium.org> Tested-by: Douglas Anderson <dianders@chromium.org> Reviewed-by: Stephen Boyd <swboyd@chromium.org> Signed-off-by: Mark Brown <broonie@kernel.org>