[PATCH v8 22/22] counter: 104-quad-8: Add IRQ support for the ACCES 104-QUAD-8
Jonathan Cameron
jic23 at kernel.org
Sun Feb 14 13:24:59 EST 2021
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...
> #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.
> 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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