[PATCH v8 22/22] counter: 104-quad-8: Add IRQ support for the ACCES 104-QUAD-8
William Breathitt Gray
vilhelm.gray at gmail.com
Fri Feb 19 04:21:47 EST 2021
On Sun, Feb 14, 2021 at 06:24:59PM +0000, Jonathan Cameron wrote:
> On Fri, 12 Feb 2021 21:13:46 +0900
> William Breathitt Gray <vilhelm.gray at gmail.com> wrote:
>
> > The LSI/CSI LS7266R1 chip provides programmable output via the FLG pins.
> > When interrupts are enabled on the ACCES 104-QUAD-8, they occur whenever
> > FLG1 is active. Four functions are available for the FLG1 signal: Carry,
> > Compare, Carry-Borrow, and Index.
> >
> > Carry:
> > Interrupt generated on active low Carry signal. Carry
> > signal toggles every time the respective channel's
> > counter overflows.
> >
> > Compare:
> > Interrupt generated on active low Compare signal.
> > Compare signal toggles every time respective channel's
> > preset register is equal to the respective channel's
> > counter.
> >
> > Carry-Borrow:
> > Interrupt generated on active low Carry signal and
> > active low Borrow signal. Carry signal toggles every
> > time the respective channel's counter overflows. Borrow
> > signal toggles every time the respective channel's
> > counter underflows.
> >
> > Index:
> > Interrupt generated on active high Index signal.
> >
> > These four functions correspond respectivefly to the following four
> > Counter event types: COUNTER_EVENT_OVERFLOW, COUNTER_EVENT_THRESHOLD,
> > COUNTER_EVENT_OVERFLOW_UNDERFLOW, and COUNTER_EVENT_INDEX. Interrupts
> > push Counter events to event channel X, where 'X' is the respective
> > channel whose FLG1 activated.
> >
> > This patch adds IRQ support for the ACCES 104-QUAD-8. The interrupt line
> > numbers for the devices may be configured via the irq array module
> > parameter.
> >
> > Cc: Syed Nayyar Waris <syednwaris at gmail.com>
> > Signed-off-by: William Breathitt Gray <vilhelm.gray at gmail.com>
>
> A few minor bits inline.
>
> Jonathan
>
> > ---
> > drivers/counter/104-quad-8.c | 170 +++++++++++++++++++++++++++++++++--
> > drivers/counter/Kconfig | 6 +-
> > 2 files changed, 165 insertions(+), 11 deletions(-)
> >
> > diff --git a/drivers/counter/104-quad-8.c b/drivers/counter/104-quad-8.c
> > index 2b47f9991acc..45090cd9f813 100644
> > --- a/drivers/counter/104-quad-8.c
> > +++ b/drivers/counter/104-quad-8.c
> > @@ -11,6 +11,7 @@
> > #include <linux/errno.h>
> > #include <linux/io.h>
> > #include <linux/ioport.h>
> > +#include <linux/interrupt.h>
> > #include <linux/isa.h>
> > #include <linux/kernel.h>
> > #include <linux/module.h>
> > @@ -25,11 +26,15 @@ static unsigned int num_quad8;
> > module_param_hw_array(base, uint, ioport, &num_quad8, 0);
> > MODULE_PARM_DESC(base, "ACCES 104-QUAD-8 base addresses");
> >
> > +static unsigned int irq[max_num_isa_dev(QUAD8_EXTENT)];
> > +module_param_hw_array(irq, uint, irq, NULL, 0);
> > +MODULE_PARM_DESC(irq, "ACCES 104-QUAD-8 interrupt line numbers");
> > +
> > #define QUAD8_NUM_COUNTERS 8
> >
> > /**
> > * struct quad8 - device private data structure
> > - * @lock: synchronization lock to prevent I/O race conditions
> > + * @lock: lock to prevent clobbering device states during R/W ops
> > * @counter: instance of the counter_device
> > * @fck_prescaler: array of filter clock prescaler configurations
> > * @preset: array of preset values
> > @@ -38,6 +43,8 @@ MODULE_PARM_DESC(base, "ACCES 104-QUAD-8 base addresses");
> > * @quadrature_scale: array of quadrature mode scale configurations
> > * @ab_enable: array of A and B inputs enable configurations
> > * @preset_enable: array of set_to_preset_on_index attribute configurations
> > + * @irq_trigger: array of current IRQ trigger function configurations
> > + * @next_irq_trigger: array of next IRQ trigger function configurations
> > * @synchronous_mode: array of index function synchronous mode configurations
> > * @index_polarity: array of index function polarity configurations
> > * @cable_fault_enable: differential encoder cable status enable configurations
> > @@ -53,13 +60,17 @@ struct quad8 {
> > unsigned int quadrature_scale[QUAD8_NUM_COUNTERS];
> > unsigned int ab_enable[QUAD8_NUM_COUNTERS];
> > unsigned int preset_enable[QUAD8_NUM_COUNTERS];
> > + unsigned int irq_trigger[QUAD8_NUM_COUNTERS];
> > + unsigned int next_irq_trigger[QUAD8_NUM_COUNTERS];
> > unsigned int synchronous_mode[QUAD8_NUM_COUNTERS];
> > unsigned int index_polarity[QUAD8_NUM_COUNTERS];
> > unsigned int cable_fault_enable;
> > unsigned int base;
> > };
> >
> > +#define QUAD8_REG_INTERRUPT_STATUS 0x10
> > #define QUAD8_REG_CHAN_OP 0x11
> > +#define QUAD8_REG_INDEX_INTERRUPT 0x12
> > #define QUAD8_REG_INDEX_INPUT_LEVELS 0x16
> > #define QUAD8_DIFF_ENCODER_CABLE_STATUS 0x17
> > /* Borrow Toggle flip-flop */
> > @@ -92,8 +103,8 @@ struct quad8 {
> > #define QUAD8_RLD_CNTR_OUT 0x10
> > /* Transfer Preset Register LSB to FCK Prescaler */
> > #define QUAD8_RLD_PRESET_PSC 0x18
> > -#define QUAD8_CHAN_OP_ENABLE_COUNTERS 0x00
>
> This seems like an unrelated change...
This register has a bit to enable the interrupt functions in addition to
the counters. When I first introduced these macro defines, I ignored
mentioning the interrupt functionality because we weren't supporting IRQ
at the time. The change in this patch here is actually a rename of this
register configuration with the new respective bit now properly enabled:
QUAD8_CHAN_OP_ENABLE_COUNTERS -> QUAD8_CHAN_OP_ENABLE_INTERRUPT_FUNC.
> > #define QUAD8_CHAN_OP_RESET_COUNTERS 0x01
> > +#define QUAD8_CHAN_OP_ENABLE_INTERRUPT_FUNC 0x04
> > #define QUAD8_CMR_QUADRATURE_X1 0x08
> > #define QUAD8_CMR_QUADRATURE_X2 0x10
> > #define QUAD8_CMR_QUADRATURE_X4 0x18
> > @@ -380,13 +391,103 @@ static int quad8_action_read(struct counter_device *counter,
> > return 0;
> > }
>
> ...
>
> > static int quad8_probe(struct device *dev, unsigned int id)
> > {
> > struct quad8 *priv;
> > int i, j;
> > unsigned int base_offset;
> > + int err;
> >
> > if (!devm_request_region(dev, base[id], QUAD8_EXTENT, dev_name(dev))) {
> > dev_err(dev, "Unable to lock port addresses (0x%X-0x%X)\n",
> > @@ -1011,6 +1157,8 @@ static int quad8_probe(struct device *dev, unsigned int id)
> >
> > raw_spin_lock_init(&priv->lock);
> >
> > + /* Reset Index/Interrupt Register */
> > + outb(0x00, base[id] + QUAD8_REG_INDEX_INTERRUPT);
> > /* Reset all counters and disable interrupt function */
> > outb(QUAD8_CHAN_OP_RESET_COUNTERS, base[id] + QUAD8_REG_CHAN_OP);
> > /* Set initial configuration for all counters */
> > @@ -1037,13 +1185,19 @@ static int quad8_probe(struct device *dev, unsigned int id)
> > outb(QUAD8_CTR_IOR, base_offset + 1);
> > /* Disable index function; negative index polarity */
> > outb(QUAD8_CTR_IDR, base_offset + 1);
> > + /* Initialize next IRQ trigger function configuration */
> > + priv->next_irq_trigger[i] = QUAD8_EVENT_NONE;
> > }
> > /* Disable Differential Encoder Cable Status for all channels */
> > outb(0xFF, base[id] + QUAD8_DIFF_ENCODER_CABLE_STATUS);
> > - /* Enable all counters */
> > - outb(QUAD8_CHAN_OP_ENABLE_COUNTERS, base[id] + QUAD8_REG_CHAN_OP);
> > + /* Enable all counters and enable interrupt function */
> > + outb(QUAD8_CHAN_OP_ENABLE_INTERRUPT_FUNC, base[id] + QUAD8_REG_CHAN_OP);
> > +
> > + err = devm_request_irq(dev, irq[id], quad8_irq_handler, IRQF_SHARED,
> > + priv->counter.name, priv);
> > + if (err)
> > + return err;
> >
> > - /* Register Counter device */
>
> Whilst I would agree with removing this comment as being pointless
> as it's obvious, it doesn't really belong in this patch.
I'll move this to its own patch.
William Breathitt Gray
> > return devm_counter_register(dev, &priv->counter);
> > }
> >
> > diff --git a/drivers/counter/Kconfig b/drivers/counter/Kconfig
> > index 1391e8ea64fe..b0f8fef18b51 100644
> > --- a/drivers/counter/Kconfig
> > +++ b/drivers/counter/Kconfig
> > @@ -23,11 +23,11 @@ config 104_QUAD_8
> > A counter's respective error flag may be cleared by performing a write
> > operation on the respective count value attribute. Although the
> > 104-QUAD-8 counters have a 25-bit range, only the lower 24 bits may be
> > - set, either directly or via the counter's preset attribute. Interrupts
> > - are not supported by this driver.
> > + set, either directly or via the counter's preset attribute.
> >
> > The base port addresses for the devices may be configured via the base
> > - array module parameter.
> > + array module parameter. The interrupt line numbers for the devices may
> > + be configured via the irq array module parameter.
> >
> > config STM32_TIMER_CNT
> > tristate "STM32 Timer encoder counter driver"
>
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