On 2017-01-04 15:13, Peter Rosin wrote:
> On 2017-01-04 10:29, 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
>> 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.
>
> Irqs are not my strong point, I would prefer if someone else also had
> a look. And there are some comments below...
>
> Cheers,
> peda
>
>> Signed-off-by: Phil Reid <preid@xxxxxxxxxxxxxxxxx>
>> ---
>> drivers/i2c/muxes/i2c-mux-pca954x.c | 126 ++++++++++++++++++++++++++++++++++++
>> 1 file changed, 126 insertions(+)
>>
>> diff --git a/drivers/i2c/muxes/i2c-mux-pca954x.c b/drivers/i2c/muxes/i2c-mux-pca954x.c
>> index 981d145..f2dba7c 100644
>> --- a/drivers/i2c/muxes/i2c-mux-pca954x.c
>> +++ b/drivers/i2c/muxes/i2c-mux-pca954x.c
>> @@ -40,14 +40,19 @@
>> #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>
>>
>> #define PCA954X_MAX_NCHANS 8
>>
>> +#define PCA954X_IRQ_OFFSET 4
>> +
>> enum pca_type {
>> pca_9540,
>> pca_9542,
>> @@ -62,6 +67,7 @@ enum pca_type {
>> struct chip_desc {
>> u8 nchans;
>> u8 enable; /* used for muxes only */
>> + u8 has_irq;
>> enum muxtype {
>> pca954x_ismux = 0,
>> pca954x_isswi
>> @@ -74,6 +80,9 @@ struct pca954x {
>> u8 last_chan; /* last register value */
>> u8 deselect;
>> struct i2c_client *client;
>> +
>> + struct irq_domain *irq;
>> + unsigned int irq_mask;
>> };
>>
>> /* Provide specs for the PCA954x types we know about */
>> @@ -86,19 +95,23 @@ 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] = {
>> @@ -203,6 +216,104 @@ 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;
>> +
>> + 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)) {
>
> Spaces around the +
>
>> + 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;
>> +
>> + data->irq_mask &= ~BIT(pos);
>> + if (!data->irq_mask)
>> + disable_irq(data->client->irq);
>> +}
>> +
>> +static void pca954x_irq_unmask(struct irq_data *idata)
>> +{
>> + struct pca954x *data = irq_data_get_irq_chip_data(idata);
>> + unsigned int pos = idata->hwirq;
>> +
>> + if (!data->irq_mask)
>> + enable_irq(data->client->irq);
>> + data->irq_mask |= BIT(pos);
>> +}
>> +
>> +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 pca953x_irq_setup(struct i2c_mux_core *muxc)
Ooop,
pca954x_irq_setup
>> +{
>> + 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;
>> +
>> + data->irq = irq_domain_add_linear(client->dev.of_node,
>> + data->chip->nchans,
>> + &irq_domain_simple_ops, data);
>> + if (!data->irq) {
>> + err = -ENODEV;
>> + goto err_irq_domain;
>
> This label is not needed, just 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,
>> + "pca953x", data);
>
> "pca954x"
>
>> + 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);
>> +err_irq_domain:
>> + return err;
>> +}
>> +
>> /*
>> * I2C init/probing/exit functions
>> */
>> @@ -258,6 +369,10 @@ static int pca954x_probe(struct i2c_client *client,
>> idle_disconnect_dt = of_node &&
>> of_property_read_bool(of_node, "i2c-mux-idle-disconnect");
>>
>> + ret = pca953x_irq_setup(muxc);
>> + if (ret)
>> + goto irq_setup_failed;
>> +
>> /* Now create an adapter for each channel */
>> for (num = 0; num < data->chip->nchans; num++) {
>> bool idle_disconnect_pd = false;
>> @@ -294,6 +409,7 @@ static int pca954x_probe(struct i2c_client *client,
>>
>> return 0;
>>
>> +irq_setup_failed:
>> virt_reg_failed:
>
> Rename the virt_reg_failed label to name what is reversed instead of what
> happened to fail. E.g. fail_del_adapters, or something.
>
>> i2c_mux_del_adapters(muxc);
>> return ret;
>> @@ -302,6 +418,16 @@ 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;
>>
>
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