On 2017-01-25 02:31, Phil Reid wrote: > Various muxes can aggregate multiple interrupts from each i2c bus. > All of the muxes with interrupt support combine the active low irq lines > using an internal 'and' function and generate a combined active low > output. The muxes do provide the ability to read a control register to > determine which irq is active. By making the mux an irq controller isr > latency can potentially be reduced by reading the status register and > then only calling the registered isr on that bus segment. > > As there is no irq masking on the mux irq are disabled until irq_unmask is > called at least once. > > Acked-by: Peter Rosin <peda@xxxxxxxxxx> > Signed-off-by: Phil Reid <preid@xxxxxxxxxxxxxxxxx> > --- > drivers/i2c/muxes/i2c-mux-pca954x.c | 141 +++++++++++++++++++++++++++++++++++- > 1 file changed, 139 insertions(+), 2 deletions(-) > > diff --git a/drivers/i2c/muxes/i2c-mux-pca954x.c b/drivers/i2c/muxes/i2c-mux-pca954x.c > index bbf088e..f55da88 100644 > --- a/drivers/i2c/muxes/i2c-mux-pca954x.c > +++ b/drivers/i2c/muxes/i2c-mux-pca954x.c > @@ -41,14 +41,20 @@ > #include <linux/i2c.h> > #include <linux/i2c-mux.h> > #include <linux/i2c/pca954x.h> > +#include <linux/interrupt.h> > +#include <linux/irq.h> > #include <linux/module.h> > #include <linux/of.h> > #include <linux/of_device.h> > +#include <linux/of_irq.h> > #include <linux/pm.h> > #include <linux/slab.h> > +#include <linux/spinlock.h> > > #define PCA954X_MAX_NCHANS 8 > > +#define PCA954X_IRQ_OFFSET 4 > + > enum pca_type { > pca_9540, > pca_9542, > @@ -63,6 +69,7 @@ enum pca_type { > struct chip_desc { > u8 nchans; > u8 enable; /* used for muxes only */ > + u8 has_irq; > enum muxtype { > pca954x_ismux = 0, > pca954x_isswi > @@ -75,6 +82,10 @@ struct pca954x { > u8 last_chan; /* last register value */ > u8 deselect; > struct i2c_client *client; > + > + struct irq_domain *irq; > + unsigned int irq_mask; > + spinlock_t lock; > }; > > /* Provide specs for the PCA954x types we know about */ > @@ -87,19 +98,23 @@ struct pca954x { > [pca_9542] = { > .nchans = 2, > .enable = 0x4, > + .has_irq = 1, > .muxtype = pca954x_ismux, > }, > [pca_9543] = { > .nchans = 2, > + .has_irq = 1, > .muxtype = pca954x_isswi, > }, > [pca_9544] = { > .nchans = 4, > .enable = 0x4, > + .has_irq = 1, > .muxtype = pca954x_ismux, > }, > [pca_9545] = { > .nchans = 4, > + .has_irq = 1, > .muxtype = pca954x_isswi, > }, > [pca_9547] = { > @@ -222,6 +237,114 @@ static int pca954x_deselect_mux(struct i2c_mux_core *muxc, u32 chan) > return pca954x_reg_write(muxc->parent, client, data->last_chan); > } > > +static irqreturn_t pca954x_irq_handler(int irq, void *dev_id) > +{ > + struct pca954x *data = dev_id; > + unsigned int child_irq; > + int ret, i, handled; See below. > + > + ret = i2c_smbus_read_byte(data->client); > + if (ret < 0) > + return IRQ_NONE; > + > + for (i = 0; i < data->chip->nchans; i++) { > + if (ret & BIT(PCA954X_IRQ_OFFSET + i)) { > + child_irq = irq_linear_revmap(data->irq, i); > + handle_nested_irq(child_irq); > + handled++; > + } > + } > + return handled ? IRQ_HANDLED : IRQ_NONE; > +} > + > +static void pca954x_irq_mask(struct irq_data *idata) > +{ > + struct pca954x *data = irq_data_get_irq_chip_data(idata); > + unsigned int pos = idata->hwirq; > + unsigned long flags; > + > + spin_lock_irqsave(&data->lock, flags); > + > + data->irq_mask &= ~BIT(pos); > + if (!data->irq_mask) > + disable_irq(data->client->irq); > + > + spin_unlock_irqrestore(&data->lock, flags); > +} > + > +static void pca954x_irq_unmask(struct irq_data *idata) > +{ > + struct pca954x *data = irq_data_get_irq_chip_data(idata); > + unsigned int pos = idata->hwirq; > + unsigned long flags; > + > + spin_lock_irqsave(&data->lock, flags); > + > + if (!data->irq_mask) > + enable_irq(data->client->irq); > + data->irq_mask |= BIT(pos); > + > + spin_unlock_irqrestore(&data->lock, flags); > +} > + > +static int pca954x_irq_set_type(struct irq_data *idata, unsigned int type) > +{ > + if ((type & IRQ_TYPE_SENSE_MASK) != IRQ_TYPE_LEVEL_LOW) > + return -EINVAL; > + return 0; > +} > + > +static struct irq_chip pca954x_irq_chip = { > + .name = "i2c-mux-pca954x", > + .irq_mask = pca954x_irq_mask, > + .irq_unmask = pca954x_irq_unmask, > + .irq_set_type = pca954x_irq_set_type, > +}; > + > +static int pca954x_irq_setup(struct i2c_mux_core *muxc) > +{ > + struct pca954x *data = i2c_mux_priv(muxc); > + struct i2c_client *client = data->client; > + int c, err, irq; > + > + if (!data->chip->has_irq || client->irq <= 0) > + return 0; > + > + spin_lock_init(&data->lock); > + > + data->irq = irq_domain_add_linear(client->dev.of_node, > + data->chip->nchans, > + &irq_domain_simple_ops, data); > + if (!data->irq) > + return -ENODEV; > + > + for (c = 0; c < data->chip->nchans; c++) { > + irq = irq_create_mapping(data->irq, c); > + irq_set_chip_data(irq, data); > + irq_set_chip_and_handler(irq, &pca954x_irq_chip, > + handle_simple_irq); > + } > + > + err = devm_request_threaded_irq(&client->dev, data->client->irq, NULL, > + pca954x_irq_handler, > + IRQF_ONESHOT | IRQF_SHARED, > + "pca954x", data); > + if (err) > + goto err_req_irq; > + > + disable_irq(data->client->irq); > + > + return 0; > +err_req_irq: > + for (c = 0; c < data->chip->nchans; c++) { > + irq = irq_find_mapping(data->irq, c); > + irq_dispose_mapping(irq); > + } > + irq_domain_remove(data->irq); > + > + return err; > +} > + > /* > * I2C init/probing/exit functions > */ > @@ -286,6 +409,10 @@ static int pca954x_probe(struct i2c_client *client, > idle_disconnect_dt = of_node && > of_property_read_bool(of_node, "i2c-mux-idle-disconnect"); > > + ret = pca954x_irq_setup(muxc); > + if (ret) > + goto fail_del_adapters; > + > /* Now create an adapter for each channel */ > for (num = 0; num < data->chip->nchans; num++) { > bool idle_disconnect_pd = false; > @@ -311,7 +438,7 @@ static int pca954x_probe(struct i2c_client *client, > dev_err(&client->dev, > "failed to register multiplexed adapter" > " %d as bus %d\n", num, force); > - goto virt_reg_failed; > + goto fail_del_adapters; > } > } > > @@ -322,7 +449,7 @@ static int pca954x_probe(struct i2c_client *client, > > return 0; > > -virt_reg_failed: > +fail_del_adapters: > i2c_mux_del_adapters(muxc); > return ret; > } > @@ -330,6 +457,16 @@ static int pca954x_probe(struct i2c_client *client, > static int pca954x_remove(struct i2c_client *client) > { > struct i2c_mux_core *muxc = i2c_get_clientdata(client); > + struct pca954x *data = i2c_mux_priv(muxc); > + int c, irq; > + > + if (data->irq) { > + for (c = 0; c < data->chip->nchans; c++) { > + irq = irq_find_mapping(data->irq, c); > + irq_dispose_mapping(irq); > + } > + irq_domain_remove(data->irq); > + } > > i2c_mux_del_adapters(muxc); > return 0; > This patch needs this obvious fixup discovered by the kbuild bot Cheers, peda --- a/drivers/i2c/muxes/i2c-mux-pca954x.c +++ b/drivers/i2c/muxes/i2c-mux-pca954x.c @@ -242,7 +242,7 @@ static irqreturn_t pca954x_irq_handler(int irq, void *dev_id) { struct pca954x *data = dev_id; unsigned int child_irq; - int ret, i, handled; + int ret, i, handled = 0; ret = i2c_smbus_read_byte(data->client); if (ret < 0) -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html