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path: root/drivers/mfd/ti_am335x_tscadc.c
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2014-03-19mfd: ti_am335x_tscadc: Use devm_ioremap_resource()Jingoo Han1-19/+4
Use devm_ioremap_resource() in order to make the code simpler, and remove redundant return value check of platform_get_resource() because the value is checked by devm_ioremap_resource(). Signed-off-by: Jingoo Han <jg1.han@samsung.com> Signed-off-by: Lee Jones <lee.jones@linaro.org>
2014-03-19mfd: Delete non-required instances of include <linux/init.h>Paul Gortmaker1-1/+0
None of these files are actually using any __init type directives and hence don't need to include <linux/init.h>. Most are just a left over from __devinit and __cpuinit removal, or simply due to code getting copied from one driver to the next. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Lee Jones <lee.jones@linaro.org>
2014-01-07mfd: input: iio: ti_amm335x: Rework TSC/ADC synchronizationSebastian Andrzej Siewior1-10/+53
The ADC driver always programs all possible ADC values and discards them except for the value IIO asked for. On the am335x-evm the driver programs four values and it takes 500us to gather them. Reducing the number of conversations down to the (required) one also reduces the busy loop down to 125us. This leads to another error, namely the FIFOCOUNT register is sometimes (like one out of 10 attempts) not updated in time leading to EBUSY. The next read has the FIFOCOUNT register updated. Checking for the ADCSTAT register for being idle isn't a good choice either. The problem is that if TSC is used at the same time, the HW completes the conversation for ADC *and* before the driver noticed it, the HW begins to perform a TSC conversation and so the driver never seen the HW idle. The next time we would have two values in the FIFO but since the driver reads everything we always see the current one. So instead of polling for the IDLE bit in ADCStatus register, we should check the FIFOCOUNT register. It should be one instead of zero because we request one value. This change in turn leads to another error. Sometimes if TSC & ADC are used together the TSC starts generating interrupts even if nobody actually touched the touchscreen. The interrupts seem valid because TSC's FIFO is filled with values for each channel of the TSC. This condition stops after a few ADC reads but will occur again. Not good. On top of this (even without the changes I just mentioned) there is a ADC & TSC lockup condition which was reported to me by Jeff Lance including the following test case: A busy loop of "cat /sys/bus/iio/devices/iio\:device0/in_voltage4_raw" and a mug on touch screen. With this setup, the hardware will lockup after something between 20 minutes and it could take up to a couple of hours. During that lockup, the ADCSTAT register says 0x30 (or 0x70) which means STEP_ID = IDLE and FSM_BUSY = yes. That means the hardware says that it is idle and busy at the same time which is an invalid condition. For all this reasons I decided to rework this TSC/ADC part and add a handshake / synchronization here: First the ADC signals that it needs the HW and writes a 0 mask into the SE register. The HW (if active) will complete the current conversation and become idle. The TSC driver will gather the values from the FIFO (woken up by an interrupt) and won't "enable" another conversation. Instead it will wake up the ADC driver which is already waiting. The ADC driver will start "its" conversation and once it is done, it will enable the TSC steps so the TSC will work again. After this rework I haven't observed the lockup so far. Plus the busy loop has been reduced from 500us to 125us. The continues-read mode remains unchanged. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Acked-by: Jonathan Cameron <jic23@kernel.org> Signed-off-by: Lee Jones <lee.jones@linaro.org>
2014-01-07mfd: ti_am335x: Drop am335x_tsc_se_update() from resume pathSebastian Andrzej Siewior1-1/+0
The update of the SE register in MFD doesn't look right as it has nothing to do with it. The better place to do it is in TSC driver (which is already doing it) and in the ADC driver which needs this only in the continues mode. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Acked-by: Jonathan Cameron <jic23@kernel.org> Signed-off-by: Lee Jones <lee.jones@linaro.org>
2014-01-07mfd: ti_am335x_tscadc: Don't read back REG_SESebastian Andrzej Siewior1-4/+12
The purpose of reg_se_cache has been defeated. It should avoid the read-back of the register to avoid the latency and the fact that the bits are reset to 0 after the individual conversation took place. The reason why this is required like this to work, is that read-back of the register removes the bits of the ADC so they do not start another conversation after the register is re-written from the TSC side for the update. To avoid the not required read-back I introduce a "set once" variant which does not update the cache mask. After the conversation completes, the bit is removed from the SE register anyway and we don't plan a new conversation "any time soon". The current set function is renamed to set_cache to distinguish the two operations. This is a small preparation for a larger sync-rework. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Acked-by: Jonathan Cameron <jic23@kernel.org> Signed-off-by: Lee Jones <lee.jones@linaro.org>
2014-01-07mfd: ti_am335x_tscadc: Make am335x_tsc_se_update() localSebastian Andrzej Siewior1-2/+1
Since the "recent" changes, am335x_tsc_se_update() has no longer any users outside of this file so make it local. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Lee Jones <lee.jones@linaro.org>
2013-10-23mfd: ti_am335x_tscadc: Avoid possible deadlock of reg_lockSebastian Andrzej Siewior1-4/+8
Since the addition of continuous sampling mode and shared irq support, the reg_lock lock can be taken with and without interrupts. This patch uses the *_irq* variant which should be used in order to avaoid a deadlock. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Lee Jones <lee.jones@linaro.org>
2013-10-23mfd: ti_am335x_tscadc: Remove redundant of_match_ptrSachin Kamat1-1/+1
The data structure of_match_ptr() protects is always compiled in. Hence of_match_ptr() is not needed. Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org> Signed-off-by: Lee Jones <lee.jones@linaro.org>
2013-10-23mfd: ti_am335x_tscadc: Restore clock divider on resumeMatthias Kaehlcke1-4/+6
The ADC clock divider needs to be restored on resume as the register content is lost when the ADC is powered down Signed-off-by: Matthias Kaehlcke <matthias@kaehlcke.net> Signed-off-by: Lee Jones <lee.jones@linaro.org>
2013-08-14mfd: ti_am335x_tscadc: Update reg_cache variable in clr functionZubair Lutfullah1-2/+2
The reg_cache variable should be updated with current steps in the reg_se register. Then the mask should apply and clear the register. Previously, the reg_cache can be an old redundant value that isn't updated. Signed-off-by: Zubair Lutfullah <zubair.lutfullah@gmail.com> Signed-off-by: Lee Jones <lee.jones@linaro.org>
2013-08-14mfd: ti_am335x_tscadc: Fix spin lock and reg_cacheZubair Lutfullah1-2/+2
Reg_cache variable is used to lock step enable register from being accessed and written by both TSC and ADC at the same time. However, it isn't updated anywhere in the code at all. If both TSC and ADC are used, eventually 1FFFF is always written enabling all 16 steps uselessly causing a mess. Patch fixes it by correcting the locks and updates the variable by reading the step enable register Signed-off-by: Zubair Lutfullah <zubair.lutfullah@gmail.com> Signed-off-by: Lee Jones <lee.jones@linaro.org>
2013-07-31MFD: ti_tscadc: Disable TSC config registers in adc modePatil, Rachna1-7/+11
AFE Pen Ctrl and TouchScreen transistors enabling is not required when only ADC mode is being used, so check for availability of TSC driver before accessing control register. Signed-off-by: Patil, Rachna <rachna@ti.com> Acked-by: Vaibhav Hiremath <hvaibhav@ti.com> Signed-off-by: Zubair Lutfullah <zubair.lutfullah@gmail.com> Signed-off-by: Lee Jones <lee.jones@linaro.org> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2013-07-31MFD: ti_tscadc: ADC Clock check not requiredPatil, Rachna1-5/+1
ADC is ideally expected to work at a frequency of 3MHz. The present code had a check, which returned error if the frequency went below the threshold value. But since AM335x supports various working frequencies, this check is not required. Now the code just uses the internal ADC clock divider to set the ADC frequency w.r.t the sys clock. Signed-off-by: Patil, Rachna <rachna@ti.com> Signed-off-by: Zubair Lutfullah <zubair.lutfullah@gmail.com> Signed-off-by: Lee Jones <lee.jones@linaro.org> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2013-06-12iio: ti_am335x_adc: Allow to specify input lineSebastian Andrzej Siewior1-2/+18
The TSC part allows to specify the input lines. The IIO part assumes that it usues always the last few, that means if IIO has adc-channels set to 2 it will use channel 6 and 7. However it might make sense to use only 6. This patch changes the device property (which was introduced recently and was never in an official release) in a way that the user can specify which of the AIN lines should be used. In Addition to this, the name is now AINx where x is the channel number i.e. for AIN6 we would have 6. Prior this, it always started counting at 0 which is confusing. In addition to this, it also checks for correct step number during reading and does not rely on proper FIFO depth. Acked-by: Jonathan Cameron <jic23@kernel.org> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
2013-06-12mfd: iio: ti_am335x_adc: rename device from tiadc to TI-am335x-adcSebastian Andrzej Siewior1-1/+1
TI-adc reads a little better compared to tiadc. And if we add am335x to it then we have the same naming scheme as the tsc side. Acked-by: Jonathan Cameron <jic23@kernel.org> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
2013-06-12mfd: input: ti_am335x_tsc: rename device from tsc to TI-am335x-tscSebastian Andrzej Siewior1-1/+1
tsc is a very generic name. This patch adds a TI and HW prefix to it less generic. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
2013-06-12mfd: ti_tscadc: deal with partial activationPantelis Antoniou1-13/+25
Fix the mfd device in the case where a subdevice might not be activated. Signed-off-by: Pantelis Antoniou <panto@antoniou-consulting.com> Signed-off-by: Felipe Balbi <balbi@ti.com> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
2013-06-12mfd: ti_am335x_tscadc: remove platform_data supportSebastian Andrzej Siewior1-17/+6
This patch removes access to platform data mfd_tscadc_board because the platform is DT only. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
2013-06-12mfd: ti_am335x_tscadc: Add DT supportPatil, Rachna1-6/+26
Add DT support in the MFD core driver. The node name is "am3359" because it was tested on this platform. Signed-off-by: Pantelis Antoniou <panto@antoniou-consulting.com> Signed-off-by: Patil, Rachna <rachna@ti.com> Signed-off-by: Felipe Balbi <balbi@ti.com> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
2013-06-12iio: ti_am335x_adc: Add DT supportPatil, Rachna1-0/+1
Add DT support for client ADC driver. Acked-by: Jonathan Cameron <jic23@kernel.org> Signed-off-by: Patil, Rachna <rachna@ti.com> Signed-off-by: Pantelis Antoniou <panto@antoniou-consulting.com> Signed-off-by: Felipe Balbi <balbi@ti.com> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
2013-06-12input: ti_am33x_tsc: Add DT supportPatil, Rachna1-0/+1
This patch adds DT support to touch driver. It also provides a binding document which is used by the MFD and IIO part of the device. This patch also renames steps_to_configure to coordinate_readouts because the original name misleads the purpose of the variable. Signed-off-by: Pantelis Antoniou <panto@antoniou-consulting.com> Signed-off-by: Patil, Rachna <rachna@ti.com> Signed-off-by: Felipe Balbi <balbi@ti.com> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
2013-06-12input: ti_am33x_tsc: Step enable bits made configurablePatil, Rachna1-1/+28
Current code has hard coded value written to step enable bits. Now the bits are updated based on how many steps are needed to be configured got from platform data. The user needs to take care not to exceed the count more than 16. While using ADC and TSC one should take care to set this parameter correctly. Sebastian added the common lock and moved the code, that manipulates the steps, from into the mfd module. Signed-off-by: Patil, Rachna <rachna@ti.com> Signed-off-by: Felipe Balbi <balbi@ti.com> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
2013-06-12mfd: input: iio: ti_am335x_adc: use one structure for ti_tscadc_devSebastian Andrzej Siewior1-4/+4
The mfd driver creates platform data for the child devices and it is the ti_tscadc_dev struct. This struct is copied for the two devices. The copy of the structure makes a common lock in this structure a little less usefull. Therefore the platform data is not a pointer to the structure and the same structure is used. While doing the change I noticed that the suspend/resume code assumes the wrong pointer for ti_tscadc_dev and this has been fixed as well. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
2013-01-03Drivers: mfd: remove __dev* attributes.Greg Kroah-Hartman1-3/+3
CONFIG_HOTPLUG is going away as an option. As a result, the __dev* markings need to be removed. This change removes the use of __devinit, __devexit_p, __devinitdata, __devinitconst, and __devexit from these drivers. Based on patches originally written by Bill Pemberton, but redone by me in order to handle some of the coding style issues better, by hand. Cc: Bill Pemberton <wfp5p@virginia.edu> Cc: Samuel Ortiz <sameo@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-26MFD: ti_am335x_tscadc: Pass correct error messagePatil, Rachna1-14/+11
Pass on the correct error message from platform_get_irq() instead of hard coding it to "EINVAL". Also change label from "err" to "ret" for better readability and update the same in error path. Signed-off-by: Patil, Rachna <rachna@ti.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2012-11-05IIO : ADC: tiadc: Add support of TI's ADC driverPatil, Rachna1-1/+17
This patch adds support for TI's ADC driver. This is a multifunctional device. Analog input lines are provided on which voltage measurements can be carried out. You can have upto 8 input lines. Signed-off-by: Patil, Rachna <rachna@ti.com> Acked-by: Jonathan Cameron <jic23@kernel.org> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2012-11-05input: TSC: ti_tsc: Convert TSC into a MFDevicePatil, Rachna1-0/+11
This patch converts touchscreen into a MFD client. All the register definitions, clock initialization, etc has been moved to MFD core driver. Signed-off-by: Patil, Rachna <rachna@ti.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2012-11-05mfd: ti_tscadc: Add support for TI's TSC/ADC MFDevicePatil, Rachna1-0/+250
Add the mfd core driver which supports touchscreen and ADC. With this patch we are only adding infrastructure to support the MFD clients. Signed-off-by: Patil, Rachna <rachna@ti.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>