From e08e19c331fb249e6dc86365ee80d16045c4aeb1 Mon Sep 17 00:00:00 2001 From: "H. Nikolaus Schaller" Date: Fri, 16 Oct 2015 14:53:38 +0200 Subject: iio:adc: add iio driver for Palmas (twl6035/7) gpadc This driver code was found as: https://android.googlesource.com/kernel/tegra/+/aaabb2e045f31e5a970109ffdaae900dd403d17e/drivers/staging/iio/adc Fixed various compilation issues and test this driver on omap5 evm. Signed-off-by: Pradeep Goudagunta Signed-off-by: H. Nikolaus Schaller Signed-off-by: Marek Belisko Acked-by: Laxman Dewangan Reviewed-by: Jonathan Cameron Acked-by: Lee Jones Signed-off-by: Jonathan Cameron --- include/linux/mfd/palmas.h | 75 +++++++++++++++++++++++++++++++--------------- 1 file changed, 51 insertions(+), 24 deletions(-) (limited to 'include') diff --git a/include/linux/mfd/palmas.h b/include/linux/mfd/palmas.h index 13e1d96935ed..c800dbc42079 100644 --- a/include/linux/mfd/palmas.h +++ b/include/linux/mfd/palmas.h @@ -134,21 +134,32 @@ struct palmas_pmic_driver_data { struct regulator_config config); }; +struct palmas_adc_wakeup_property { + int adc_channel_number; + int adc_high_threshold; + int adc_low_threshold; +}; + struct palmas_gpadc_platform_data { /* Channel 3 current source is only enabled during conversion */ - int ch3_current; + int ch3_current; /* 0: off; 1: 10uA; 2: 400uA; 3: 800 uA */ /* Channel 0 current source can be used for battery detection. * If used for battery detection this will cause a permanent current * consumption depending on current level set here. */ - int ch0_current; + int ch0_current; /* 0: off; 1: 5uA; 2: 15uA; 3: 20 uA */ + bool extended_delay; /* use extended delay for conversion */ /* default BAT_REMOVAL_DAT setting on device probe */ int bat_removal; /* Sets the START_POLARITY bit in the RT_CTRL register */ int start_polarity; + + int auto_conversion_period_ms; + struct palmas_adc_wakeup_property *adc_wakeup1_data; + struct palmas_adc_wakeup_property *adc_wakeup2_data; }; struct palmas_reg_init { @@ -405,28 +416,7 @@ struct palmas_gpadc_calibration { s32 offset_error; }; -struct palmas_gpadc { - struct device *dev; - struct palmas *palmas; - - int ch3_current; - int ch0_current; - - int gpadc_force; - - int bat_removal; - - struct mutex reading_lock; - struct completion irq_complete; - - int eoc_sw_irq; - - struct palmas_gpadc_calibration *palmas_cal_tbl; - - int conv0_channel; - int conv1_channel; - int rt_channel; -}; +#define PALMAS_DATASHEET_NAME(_name) "palmas-gpadc-chan-"#_name struct palmas_gpadc_result { s32 raw_code; @@ -520,6 +510,43 @@ enum palmas_irqs { PALMAS_NUM_IRQ, }; +/* Palmas GPADC Channels */ +enum { + PALMAS_ADC_CH_IN0, + PALMAS_ADC_CH_IN1, + PALMAS_ADC_CH_IN2, + PALMAS_ADC_CH_IN3, + PALMAS_ADC_CH_IN4, + PALMAS_ADC_CH_IN5, + PALMAS_ADC_CH_IN6, + PALMAS_ADC_CH_IN7, + PALMAS_ADC_CH_IN8, + PALMAS_ADC_CH_IN9, + PALMAS_ADC_CH_IN10, + PALMAS_ADC_CH_IN11, + PALMAS_ADC_CH_IN12, + PALMAS_ADC_CH_IN13, + PALMAS_ADC_CH_IN14, + PALMAS_ADC_CH_IN15, + PALMAS_ADC_CH_MAX, +}; + +/* Palmas GPADC Channel0 Current Source */ +enum { + PALMAS_ADC_CH0_CURRENT_SRC_0, + PALMAS_ADC_CH0_CURRENT_SRC_5, + PALMAS_ADC_CH0_CURRENT_SRC_15, + PALMAS_ADC_CH0_CURRENT_SRC_20, +}; + +/* Palmas GPADC Channel3 Current Source */ +enum { + PALMAS_ADC_CH3_CURRENT_SRC_0, + PALMAS_ADC_CH3_CURRENT_SRC_10, + PALMAS_ADC_CH3_CURRENT_SRC_400, + PALMAS_ADC_CH3_CURRENT_SRC_800, +}; + struct palmas_pmic { struct palmas *palmas; struct device *dev; -- cgit v1.2.3 From b440655b896b2d5a2fb5f918801fb0e281a537cd Mon Sep 17 00:00:00 2001 From: Lars-Peter Clausen Date: Tue, 13 Oct 2015 18:10:26 +0200 Subject: iio: Add support for indicating fixed watermarks For buffers which have a fixed wake-up watermark the watermark attribute should be read-only. Add a new FIXED_WATERMARK flag to the struct iio_buffer_access_funcs, which can be set by a buffer implementation. Signed-off-by: Lars-Peter Clausen Signed-off-by: Jonathan Cameron --- include/linux/iio/buffer.h | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'include') diff --git a/include/linux/iio/buffer.h b/include/linux/iio/buffer.h index 1600c55828e0..4d99a53d1fe7 100644 --- a/include/linux/iio/buffer.h +++ b/include/linux/iio/buffer.h @@ -17,6 +17,12 @@ struct iio_buffer; +/** + * INDIO_BUFFER_FLAG_FIXED_WATERMARK - Watermark level of the buffer can not be + * configured. It has a fixed value which will be buffer specific. + */ +#define INDIO_BUFFER_FLAG_FIXED_WATERMARK BIT(0) + /** * struct iio_buffer_access_funcs - access functions for buffers. * @store_to: actually store stuff to the buffer @@ -30,6 +36,7 @@ struct iio_buffer; * @release: called when the last reference to the buffer is dropped, * should free all resources allocated by the buffer. * @modes: Supported operating modes by this buffer type + * @flags: A bitmask combination of INDIO_BUFFER_FLAG_* * * The purpose of this structure is to make the buffer element * modular as event for a given driver, different usecases may require @@ -54,6 +61,7 @@ struct iio_buffer_access_funcs { void (*release)(struct iio_buffer *buffer); unsigned int modes; + unsigned int flags; }; /** -- cgit v1.2.3 From e18a2ad45caeb11226e49c25068d0f2efe2adf6c Mon Sep 17 00:00:00 2001 From: Lars-Peter Clausen Date: Tue, 13 Oct 2015 18:10:27 +0200 Subject: iio: Add buffer enable/disable callbacks This patch adds a enable and disable callback that is called when the buffer is enabled/disabled. This can be used by buffer implementations that need to do some setup or teardown work. E.g. a DMA based buffer can use this to start/stop the DMA transfer. Signed-off-by: Lars-Peter Clausen Signed-off-by: Jonathan Cameron --- include/linux/iio/buffer.h | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'include') diff --git a/include/linux/iio/buffer.h b/include/linux/iio/buffer.h index 4d99a53d1fe7..2ec3ad58e8a0 100644 --- a/include/linux/iio/buffer.h +++ b/include/linux/iio/buffer.h @@ -33,6 +33,11 @@ struct iio_buffer; * storage. * @set_bytes_per_datum:set number of bytes per datum * @set_length: set number of datums in buffer + * @enable: called if the buffer is attached to a device and the + * device starts sampling. Calls are balanced with + * @disable. + * @disable: called if the buffer is attached to a device and the + * device stops sampling. Calles are balanced with @enable. * @release: called when the last reference to the buffer is dropped, * should free all resources allocated by the buffer. * @modes: Supported operating modes by this buffer type @@ -58,6 +63,9 @@ struct iio_buffer_access_funcs { int (*set_bytes_per_datum)(struct iio_buffer *buffer, size_t bpd); int (*set_length)(struct iio_buffer *buffer, int length); + int (*enable)(struct iio_buffer *buffer, struct iio_dev *indio_dev); + int (*disable)(struct iio_buffer *buffer, struct iio_dev *indio_dev); + void (*release)(struct iio_buffer *buffer); unsigned int modes; -- cgit v1.2.3 From 670b19ae9bfdbcb4ce2c2ffb2ec1659a7f4a2074 Mon Sep 17 00:00:00 2001 From: Lars-Peter Clausen Date: Tue, 13 Oct 2015 18:10:28 +0200 Subject: iio: Add generic DMA buffer infrastructure The traditional approach used in IIO to implement buffered capture requires the generation of at least one interrupt per sample. In the interrupt handler the driver reads the sample from the device and copies it to a software buffer. This approach has a rather large per sample overhead associated with it. And while it works fine for samplerates in the range of up to 1000 samples per second it starts to consume a rather large share of the available CPU processing time once we go beyond that, this is especially true on an embedded system with limited processing power. The regular interrupt also causes increased power consumption by not allowing the hardware into deeper sleep states, which is something that becomes more and more important on mobile battery powered devices. And while the recently added watermark support mitigates some of the issues by allowing the device to generate interrupts at a rate lower than the data output rate, this still requires a storage buffer inside the device and even if it exists it is only a few 100 samples deep at most. DMA support on the other hand allows to capture multiple millions or even more samples without any CPU interaction. This allows the CPU to either go to sleep for longer periods or focus on other tasks which increases overall system performance and power consumption. In addition to that some devices might not even offer a way to read the data other than using DMA, which makes DMA mandatory to use for them. The tasks involved in implementing a DMA buffer can be divided into two categories. The first category is memory buffer management (allocation, mapping, etc.) and hooking this up the IIO buffer callbacks like read(), enable(), disable(), etc. The second category of tasks is to setup the DMA hardware and manage the DMA transfers. Tasks from the first category will be very similar for all IIO drivers supporting DMA buffers, while the tasks from the second category will be hardware specific. This patch implements a generic infrastructure that take care of the former tasks. It provides a set of functions that implement the standard IIO buffer iio_buffer_access_funcs callbacks. These can either be used as is or be overloaded and augmented with driver specific code where necessary. For the DMA buffer support infrastructure that is introduced in this series sample data is grouped by so called blocks. A block is the basic unit at which data is exchanged between the application and the hardware. The application is responsible for allocating the memory associated with the block and then passes the block to the hardware. When the hardware has captured the amount of samples equal to size of a block it will notify the application, which can then read the data from the block and process it. The block size can freely chosen (within the constraints of the hardware). This allows to make a trade-off between latency and management overhead. The larger the block size the lower the per sample overhead but the latency between when the data was captured and when the application will be able to access it increases, in a similar way smaller block sizes have a larger per sample management overhead but a lower latency. The ideal block size thus depends on system and application requirements. For the time being the infrastructure only implements a simple double buffered scheme which allocates two blocks each with half the size of the configured buffer size. This provides basic support for capturing continuous uninterrupted data over the existing file-IO ABI. Future extensions to the DMA buffer infrastructure will give applications a more fine grained control over how many blocks are allocated and the size of each block. But this requires userspace ABI additions which are intentionally not part of this patch and will be added separately. Tasks of the second category need to be implemented by a device specific driver. They can be hooked up into the generic infrastructure using two simple callbacks, submit() and abort(). The submit() callback is used to schedule DMA transfers for blocks. Once a DMA transfer has been completed it is expected that the buffer driver calls iio_dma_buffer_block_done() to notify. The abort() callback is used for stopping all pending and active DMA transfers when the buffer is disabled. Signed-off-by: Lars-Peter Clausen Signed-off-by: Jonathan Cameron --- include/linux/iio/buffer-dma.h | 152 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 152 insertions(+) create mode 100644 include/linux/iio/buffer-dma.h (limited to 'include') diff --git a/include/linux/iio/buffer-dma.h b/include/linux/iio/buffer-dma.h new file mode 100644 index 000000000000..767467d886de --- /dev/null +++ b/include/linux/iio/buffer-dma.h @@ -0,0 +1,152 @@ +/* + * Copyright 2013-2015 Analog Devices Inc. + * Author: Lars-Peter Clausen + * + * Licensed under the GPL-2. + */ + +#ifndef __INDUSTRIALIO_DMA_BUFFER_H__ +#define __INDUSTRIALIO_DMA_BUFFER_H__ + +#include +#include +#include +#include +#include + +struct iio_dma_buffer_queue; +struct iio_dma_buffer_ops; +struct device; + +struct iio_buffer_block { + u32 size; + u32 bytes_used; +}; + +/** + * enum iio_block_state - State of a struct iio_dma_buffer_block + * @IIO_BLOCK_STATE_DEQUEUED: Block is not queued + * @IIO_BLOCK_STATE_QUEUED: Block is on the incoming queue + * @IIO_BLOCK_STATE_ACTIVE: Block is currently being processed by the DMA + * @IIO_BLOCK_STATE_DONE: Block is on the outgoing queue + * @IIO_BLOCK_STATE_DEAD: Block has been marked as to be freed + */ +enum iio_block_state { + IIO_BLOCK_STATE_DEQUEUED, + IIO_BLOCK_STATE_QUEUED, + IIO_BLOCK_STATE_ACTIVE, + IIO_BLOCK_STATE_DONE, + IIO_BLOCK_STATE_DEAD, +}; + +/** + * struct iio_dma_buffer_block - IIO buffer block + * @head: List head + * @size: Total size of the block in bytes + * @bytes_used: Number of bytes that contain valid data + * @vaddr: Virutal address of the blocks memory + * @phys_addr: Physical address of the blocks memory + * @queue: Parent DMA buffer queue + * @kref: kref used to manage the lifetime of block + * @state: Current state of the block + */ +struct iio_dma_buffer_block { + /* May only be accessed by the owner of the block */ + struct list_head head; + size_t bytes_used; + + /* + * Set during allocation, constant thereafter. May be accessed read-only + * by anybody holding a reference to the block. + */ + void *vaddr; + dma_addr_t phys_addr; + size_t size; + struct iio_dma_buffer_queue *queue; + + /* Must not be accessed outside the core. */ + struct kref kref; + /* + * Must not be accessed outside the core. Access needs to hold + * queue->list_lock if the block is not owned by the core. + */ + enum iio_block_state state; +}; + +/** + * struct iio_dma_buffer_queue_fileio - FileIO state for the DMA buffer + * @blocks: Buffer blocks used for fileio + * @active_block: Block being used in read() + * @pos: Read offset in the active block + * @block_size: Size of each block + */ +struct iio_dma_buffer_queue_fileio { + struct iio_dma_buffer_block *blocks[2]; + struct iio_dma_buffer_block *active_block; + size_t pos; + size_t block_size; +}; + +/** + * struct iio_dma_buffer_queue - DMA buffer base structure + * @buffer: IIO buffer base structure + * @dev: Parent device + * @ops: DMA buffer callbacks + * @lock: Protects the incoming list, active and the fields in the fileio + * substruct + * @list_lock: Protects lists that contain blocks which can be modified in + * atomic context as well as blocks on those lists. This is the outgoing queue + * list and typically also a list of active blocks in the part that handles + * the DMA controller + * @incoming: List of buffers on the incoming queue + * @outgoing: List of buffers on the outgoing queue + * @active: Whether the buffer is currently active + * @fileio: FileIO state + */ +struct iio_dma_buffer_queue { + struct iio_buffer buffer; + struct device *dev; + const struct iio_dma_buffer_ops *ops; + + struct mutex lock; + spinlock_t list_lock; + struct list_head incoming; + struct list_head outgoing; + + bool active; + + struct iio_dma_buffer_queue_fileio fileio; +}; + +/** + * struct iio_dma_buffer_ops - DMA buffer callback operations + * @submit: Called when a block is submitted to the DMA controller + * @abort: Should abort all pending transfers + */ +struct iio_dma_buffer_ops { + int (*submit)(struct iio_dma_buffer_queue *queue, + struct iio_dma_buffer_block *block); + void (*abort)(struct iio_dma_buffer_queue *queue); +}; + +void iio_dma_buffer_block_done(struct iio_dma_buffer_block *block); +void iio_dma_buffer_block_list_abort(struct iio_dma_buffer_queue *queue, + struct list_head *list); + +int iio_dma_buffer_enable(struct iio_buffer *buffer, + struct iio_dev *indio_dev); +int iio_dma_buffer_disable(struct iio_buffer *buffer, + struct iio_dev *indio_dev); +int iio_dma_buffer_read(struct iio_buffer *buffer, size_t n, + char __user *user_buffer); +size_t iio_dma_buffer_data_available(struct iio_buffer *buffer); +int iio_dma_buffer_set_bytes_per_datum(struct iio_buffer *buffer, size_t bpd); +int iio_dma_buffer_set_length(struct iio_buffer *buffer, int length); +int iio_dma_buffer_request_update(struct iio_buffer *buffer); + +int iio_dma_buffer_init(struct iio_dma_buffer_queue *queue, + struct device *dma_dev, const struct iio_dma_buffer_ops *ops); +void iio_dma_buffer_exit(struct iio_dma_buffer_queue *queue); +void iio_dma_buffer_release(struct iio_dma_buffer_queue *queue); + +#endif -- cgit v1.2.3 From 2d6ca60f328450ff5c7802d0857d12e3711348ce Mon Sep 17 00:00:00 2001 From: Lars-Peter Clausen Date: Tue, 13 Oct 2015 18:10:29 +0200 Subject: iio: Add a DMAengine framework based buffer Add a generic fully device independent DMA buffer implementation that uses the DMAegnine framework to perform the DMA transfers. This can be used by converter drivers that whish to provide a DMA buffer for converters that are connected to a DMA core that implements the DMAengine API. Apart from allocating the buffer using iio_dmaengine_buffer_alloc() and freeing it using iio_dmaengine_buffer_free() no additional converter driver specific code is required when using this DMA buffer implementation. Signed-off-by: Lars-Peter Clausen Signed-off-by: Jonathan Cameron --- include/linux/iio/buffer-dmaengine.h | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) create mode 100644 include/linux/iio/buffer-dmaengine.h (limited to 'include') diff --git a/include/linux/iio/buffer-dmaengine.h b/include/linux/iio/buffer-dmaengine.h new file mode 100644 index 000000000000..5dcddf427bb0 --- /dev/null +++ b/include/linux/iio/buffer-dmaengine.h @@ -0,0 +1,18 @@ +/* + * Copyright 2014-2015 Analog Devices Inc. + * Author: Lars-Peter Clausen + * + * Licensed under the GPL-2 or later. + */ + +#ifndef __IIO_DMAENGINE_H__ +#define __IIO_DMAENGINE_H__ + +struct iio_buffer; +struct device; + +struct iio_buffer *iio_dmaengine_buffer_alloc(struct device *dev, + const char *channel); +void iio_dmaengine_buffer_free(struct iio_buffer *buffer); + +#endif -- cgit v1.2.3