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-rw-r--r--Documentation/driver-api/fpga/fpga-mgr.rst5
-rw-r--r--Documentation/driver-api/gpio/board.rst24
-rw-r--r--Documentation/driver-api/gpio/consumer.rst64
-rw-r--r--Documentation/driver-api/gpio/driver.rst23
-rw-r--r--Documentation/driver-api/gpio/index.rst2
-rw-r--r--Documentation/driver-api/mtdnand.rst34
6 files changed, 111 insertions, 41 deletions
diff --git a/Documentation/driver-api/fpga/fpga-mgr.rst b/Documentation/driver-api/fpga/fpga-mgr.rst
index 4b3825da48d9..82b6dbbd31cd 100644
--- a/Documentation/driver-api/fpga/fpga-mgr.rst
+++ b/Documentation/driver-api/fpga/fpga-mgr.rst
@@ -184,6 +184,11 @@ API for implementing a new FPGA Manager driver
API for programming an FPGA
---------------------------
+FPGA Manager flags
+
+.. kernel-doc:: include/linux/fpga/fpga-mgr.h
+ :doc: FPGA Manager flags
+
.. kernel-doc:: include/linux/fpga/fpga-mgr.h
:functions: fpga_image_info
diff --git a/Documentation/driver-api/gpio/board.rst b/Documentation/driver-api/gpio/board.rst
index 2c112553df84..a0f294e2e250 100644
--- a/Documentation/driver-api/gpio/board.rst
+++ b/Documentation/driver-api/gpio/board.rst
@@ -193,3 +193,27 @@ And the table can be added to the board code as follows::
The line will be hogged as soon as the gpiochip is created or - in case the
chip was created earlier - when the hog table is registered.
+
+Arrays of pins
+--------------
+In addition to requesting pins belonging to a function one by one, a device may
+also request an array of pins assigned to the function. The way those pins are
+mapped to the device determines if the array qualifies for fast bitmap
+processing. If yes, a bitmap is passed over get/set array functions directly
+between a caller and a respective .get/set_multiple() callback of a GPIO chip.
+
+In order to qualify for fast bitmap processing, the array must meet the
+following requirements:
+- pin hardware number of array member 0 must also be 0,
+- pin hardware numbers of consecutive array members which belong to the same
+ chip as member 0 does must also match their array indexes.
+
+Otherwise fast bitmap processing path is not used in order to avoid consecutive
+pins which belong to the same chip but are not in hardware order being processed
+separately.
+
+If the array applies for fast bitmap processing path, pins which belong to
+different chips than member 0 does, as well as those with indexes different from
+their hardware pin numbers, are excluded from the fast path, both input and
+output. Moreover, open drain and open source pins are excluded from fast bitmap
+output processing.
diff --git a/Documentation/driver-api/gpio/consumer.rst b/Documentation/driver-api/gpio/consumer.rst
index aa03f389d41d..5e4d8aa68913 100644
--- a/Documentation/driver-api/gpio/consumer.rst
+++ b/Documentation/driver-api/gpio/consumer.rst
@@ -109,9 +109,11 @@ For a function using multiple GPIOs all of those can be obtained with one call::
enum gpiod_flags flags)
This function returns a struct gpio_descs which contains an array of
-descriptors::
+descriptors. It also contains a pointer to a gpiolib private structure which,
+if passed back to get/set array functions, may speed up I/O proocessing::
struct gpio_descs {
+ struct gpio_array *info;
unsigned int ndescs;
struct gpio_desc *desc[];
}
@@ -323,29 +325,37 @@ The following functions get or set the values of an array of GPIOs::
int gpiod_get_array_value(unsigned int array_size,
struct gpio_desc **desc_array,
- int *value_array);
+ struct gpio_array *array_info,
+ unsigned long *value_bitmap);
int gpiod_get_raw_array_value(unsigned int array_size,
struct gpio_desc **desc_array,
- int *value_array);
+ struct gpio_array *array_info,
+ unsigned long *value_bitmap);
int gpiod_get_array_value_cansleep(unsigned int array_size,
struct gpio_desc **desc_array,
- int *value_array);
+ struct gpio_array *array_info,
+ unsigned long *value_bitmap);
int gpiod_get_raw_array_value_cansleep(unsigned int array_size,
struct gpio_desc **desc_array,
- int *value_array);
-
- void gpiod_set_array_value(unsigned int array_size,
- struct gpio_desc **desc_array,
- int *value_array)
- void gpiod_set_raw_array_value(unsigned int array_size,
- struct gpio_desc **desc_array,
- int *value_array)
- void gpiod_set_array_value_cansleep(unsigned int array_size,
- struct gpio_desc **desc_array,
- int *value_array)
- void gpiod_set_raw_array_value_cansleep(unsigned int array_size,
- struct gpio_desc **desc_array,
- int *value_array)
+ struct gpio_array *array_info,
+ unsigned long *value_bitmap);
+
+ int gpiod_set_array_value(unsigned int array_size,
+ struct gpio_desc **desc_array,
+ struct gpio_array *array_info,
+ unsigned long *value_bitmap)
+ int gpiod_set_raw_array_value(unsigned int array_size,
+ struct gpio_desc **desc_array,
+ struct gpio_array *array_info,
+ unsigned long *value_bitmap)
+ int gpiod_set_array_value_cansleep(unsigned int array_size,
+ struct gpio_desc **desc_array,
+ struct gpio_array *array_info,
+ unsigned long *value_bitmap)
+ int gpiod_set_raw_array_value_cansleep(unsigned int array_size,
+ struct gpio_desc **desc_array,
+ struct gpio_array *array_info,
+ unsigned long *value_bitmap)
The array can be an arbitrary set of GPIOs. The functions will try to access
GPIOs belonging to the same bank or chip simultaneously if supported by the
@@ -356,8 +366,9 @@ accessed sequentially.
The functions take three arguments:
* array_size - the number of array elements
* desc_array - an array of GPIO descriptors
- * value_array - an array to store the GPIOs' values (get) or
- an array of values to assign to the GPIOs (set)
+ * array_info - optional information obtained from gpiod_array_get()
+ * value_bitmap - a bitmap to store the GPIOs' values (get) or
+ a bitmap of values to assign to the GPIOs (set)
The descriptor array can be obtained using the gpiod_get_array() function
or one of its variants. If the group of descriptors returned by that function
@@ -366,16 +377,25 @@ the struct gpio_descs returned by gpiod_get_array()::
struct gpio_descs *my_gpio_descs = gpiod_get_array(...);
gpiod_set_array_value(my_gpio_descs->ndescs, my_gpio_descs->desc,
- my_gpio_values);
+ my_gpio_descs->info, my_gpio_value_bitmap);
It is also possible to access a completely arbitrary array of descriptors. The
descriptors may be obtained using any combination of gpiod_get() and
gpiod_get_array(). Afterwards the array of descriptors has to be setup
-manually before it can be passed to one of the above functions.
+manually before it can be passed to one of the above functions. In that case,
+array_info should be set to NULL.
Note that for optimal performance GPIOs belonging to the same chip should be
contiguous within the array of descriptors.
+Still better performance may be achieved if array indexes of the descriptors
+match hardware pin numbers of a single chip. If an array passed to a get/set
+array function matches the one obtained from gpiod_get_array() and array_info
+associated with the array is also passed, the function may take a fast bitmap
+processing path, passing the value_bitmap argument directly to the respective
+.get/set_multiple() callback of the chip. That allows for utilization of GPIO
+banks as data I/O ports without much loss of performance.
+
The return value of gpiod_get_array_value() and its variants is 0 on success
or negative on error. Note the difference to gpiod_get_value(), which returns
0 or 1 on success to convey the GPIO value. With the array functions, the GPIO
diff --git a/Documentation/driver-api/gpio/driver.rst b/Documentation/driver-api/gpio/driver.rst
index cbe0242842d1..a6c14ff0c54f 100644
--- a/Documentation/driver-api/gpio/driver.rst
+++ b/Documentation/driver-api/gpio/driver.rst
@@ -374,7 +374,28 @@ When implementing an irqchip inside a GPIO driver, these two functions should
typically be called in the .startup() and .shutdown() callbacks from the
irqchip.
-When using the gpiolib irqchip helpers, these callback are automatically
+When using the gpiolib irqchip helpers, these callbacks are automatically
+assigned.
+
+
+Disabling and enabling IRQs
+---------------------------
+When a GPIO is used as an IRQ signal, then gpiolib also needs to know if
+the IRQ is enabled or disabled. In order to inform gpiolib about this,
+a driver should call::
+
+ void gpiochip_disable_irq(struct gpio_chip *chip, unsigned int offset)
+
+This allows drivers to drive the GPIO as an output while the IRQ is
+disabled. When the IRQ is enabled again, a driver should call::
+
+ void gpiochip_enable_irq(struct gpio_chip *chip, unsigned int offset)
+
+When implementing an irqchip inside a GPIO driver, these two functions should
+typically be called in the .irq_disable() and .irq_enable() callbacks from the
+irqchip.
+
+When using the gpiolib irqchip helpers, these callbacks are automatically
assigned.
Real-Time compliance for GPIO IRQ chips
diff --git a/Documentation/driver-api/gpio/index.rst b/Documentation/driver-api/gpio/index.rst
index 6a374ded1287..c5b8467f9104 100644
--- a/Documentation/driver-api/gpio/index.rst
+++ b/Documentation/driver-api/gpio/index.rst
@@ -38,7 +38,7 @@ Device tree support
Device-managed API
==================
-.. kernel-doc:: drivers/gpio/devres.c
+.. kernel-doc:: drivers/gpio/gpiolib-devres.c
:export:
sysfs helpers
diff --git a/Documentation/driver-api/mtdnand.rst b/Documentation/driver-api/mtdnand.rst
index c55a6034c397..55447659b81f 100644
--- a/Documentation/driver-api/mtdnand.rst
+++ b/Documentation/driver-api/mtdnand.rst
@@ -180,10 +180,10 @@ by a chip select decoder.
{
struct nand_chip *this = mtd_to_nand(mtd);
switch(cmd){
- case NAND_CTL_SETCLE: this->IO_ADDR_W |= CLE_ADRR_BIT; break;
- case NAND_CTL_CLRCLE: this->IO_ADDR_W &= ~CLE_ADRR_BIT; break;
- case NAND_CTL_SETALE: this->IO_ADDR_W |= ALE_ADRR_BIT; break;
- case NAND_CTL_CLRALE: this->IO_ADDR_W &= ~ALE_ADRR_BIT; break;
+ case NAND_CTL_SETCLE: this->legacy.IO_ADDR_W |= CLE_ADRR_BIT; break;
+ case NAND_CTL_CLRCLE: this->legacy.IO_ADDR_W &= ~CLE_ADRR_BIT; break;
+ case NAND_CTL_SETALE: this->legacy.IO_ADDR_W |= ALE_ADRR_BIT; break;
+ case NAND_CTL_CLRALE: this->legacy.IO_ADDR_W &= ~ALE_ADRR_BIT; break;
}
}
@@ -197,7 +197,7 @@ to read back the state of the pin. The function has no arguments and
should return 0, if the device is busy (R/B pin is low) and 1, if the
device is ready (R/B pin is high). If the hardware interface does not
give access to the ready busy pin, then the function must not be defined
-and the function pointer this->dev_ready is set to NULL.
+and the function pointer this->legacy.dev_ready is set to NULL.
Init function
-------------
@@ -235,18 +235,18 @@ necessary information about the device.
}
/* Set address of NAND IO lines */
- this->IO_ADDR_R = baseaddr;
- this->IO_ADDR_W = baseaddr;
+ this->legacy.IO_ADDR_R = baseaddr;
+ this->legacy.IO_ADDR_W = baseaddr;
/* Reference hardware control function */
this->hwcontrol = board_hwcontrol;
/* Set command delay time, see datasheet for correct value */
- this->chip_delay = CHIP_DEPENDEND_COMMAND_DELAY;
+ this->legacy.chip_delay = CHIP_DEPENDEND_COMMAND_DELAY;
/* Assign the device ready function, if available */
- this->dev_ready = board_dev_ready;
+ this->legacy.dev_ready = board_dev_ready;
this->eccmode = NAND_ECC_SOFT;
/* Scan to find existence of the device */
- if (nand_scan (board_mtd, 1)) {
+ if (nand_scan (this, 1)) {
err = -ENXIO;
goto out_ior;
}
@@ -277,7 +277,7 @@ unregisters the partitions in the MTD layer.
static void __exit board_cleanup (void)
{
/* Release resources, unregister device */
- nand_release (board_mtd);
+ nand_release (mtd_to_nand(board_mtd));
/* unmap physical address */
iounmap(baseaddr);
@@ -336,17 +336,17 @@ connected to an address decoder.
struct nand_chip *this = mtd_to_nand(mtd);
/* Deselect all chips */
- this->IO_ADDR_R &= ~BOARD_NAND_ADDR_MASK;
- this->IO_ADDR_W &= ~BOARD_NAND_ADDR_MASK;
+ this->legacy.IO_ADDR_R &= ~BOARD_NAND_ADDR_MASK;
+ this->legacy.IO_ADDR_W &= ~BOARD_NAND_ADDR_MASK;
switch (chip) {
case 0:
- this->IO_ADDR_R |= BOARD_NAND_ADDR_CHIP0;
- this->IO_ADDR_W |= BOARD_NAND_ADDR_CHIP0;
+ this->legacy.IO_ADDR_R |= BOARD_NAND_ADDR_CHIP0;
+ this->legacy.IO_ADDR_W |= BOARD_NAND_ADDR_CHIP0;
break;
....
case n:
- this->IO_ADDR_R |= BOARD_NAND_ADDR_CHIPn;
- this->IO_ADDR_W |= BOARD_NAND_ADDR_CHIPn;
+ this->legacy.IO_ADDR_R |= BOARD_NAND_ADDR_CHIPn;
+ this->legacy.IO_ADDR_W |= BOARD_NAND_ADDR_CHIPn;
break;
}
}