[PATCH 1/6] regmap-irq: Add no_status support

William Breathitt Gray
2023-02-17T16:49:59Z

Some devices lack status registers, yet expect to handle interrupts.
Introduce a no_status flag to indicate such a configuration, where
rather than read a status register to verify, all interrupts received
are assumed to be active.

Cc: Mark Brown <broonie@kernel.org>
Signed-off-by: William Breathitt Gray <william.gray@linaro.org>
---
drivers/base/regmap/regmap-irq.c | 23 ++++++++++++++++-------
include/linux/regmap.h | 2 ++
2 files changed, 18 insertions(+), 7 deletions(-)

diff --git a/drivers/base/regmap/regmap-irq.c b/drivers/base/regmap/regmap-irq.c
index a8f185430a07..7abc42c5794d 100644
--- a/drivers/base/regmap/regmap-irq.c
+++ b/drivers/base/regmap/regmap-irq.c
@@ -437,7 +437,11 @@ static irqreturn_t regmap_irq_thread(int irq, void *d)
* possible in order to reduce the I/O overheads.
*/

- if (chip->num_main_regs) {
+ if (chip->no_status) {
+ /* no status register so default to all active */
+ memset(data->status_buf, 0xFF,
+ chip->num_regs * sizeof(*data->status_buf));
+ } else if (chip->num_main_regs) {
unsigned int max_main_bits;
unsigned long size;

@@ -967,12 +971,17 @@ int regmap_add_irq_chip_fwnode(struct fwnode_handle *fwnode,
continue;

/* Ack masked but set interrupts */
- reg = d->get_irq_reg(d, d->chip->status_base, i);
- ret = regmap_read(map, reg, &d->status_buf[i]);
- if (ret != 0) {
- dev_err(map->dev, "Failed to read IRQ status: %d\n",
- ret);
- goto err_alloc;
+ if (d->chip->no_status) {
+ /* no status register so default to all active */
+ d->status_buf[i] = -1;
+ } else {
+ reg = d->get_irq_reg(d, d->chip->status_base, i);
+ ret = regmap_read(map, reg, &d->status_buf[i]);
+ if (ret != 0) {
+ dev_err(map->dev, "Failed to read IRQ status: %d\n",
+ ret);
+ goto err_alloc;
+ }
}

if (chip->status_invert)
diff --git a/include/linux/regmap.h b/include/linux/regmap.h
index a3bc695bcca0..12637c4d231e 100644
--- a/include/linux/regmap.h
+++ b/include/linux/regmap.h
@@ -1563,6 +1563,7 @@ struct regmap_irq_chip_data;
* can be accomplished with a @get_irq_reg callback, without
* the need for a @sub_reg_offsets table.
* @status_invert: Inverted status register: cleared bits are active interrupts.
+ * @no_status: No status register: all interrupts assumed generated by device.
* @runtime_pm: Hold a runtime PM lock on the device when accessing it.
*
* @num_regs: Number of registers in each control bank.
@@ -1630,6 +1631,7 @@ struct regmap_irq_chip {
unsigned int clear_on_unmask:1;
unsigned int not_fixed_stride:1;
unsigned int status_invert:1;
+ unsigned int no_status:1;

int num_regs;

--
2.39.1