From f8251f1dfda9e1200545bf19270d9df2273bdfa1 Mon Sep 17 00:00:00 2001 From: Phil Reid Date: Wed, 25 Jan 2017 09:31:06 +0800 Subject: [PATCH 1/3] i2c: mux: pca954x: Add missing pca9542 definition to chip_desc The spec for the pca954x was missing. This chip is the same as the pca9540 except that it has interrupt lines. While the i2c_device_id table mapped the pca9542 to the pca9540 definition the compatible table did not. In preparation for irq support add the pca9542 definition. Signed-off-by: Phil Reid Signed-off-by: Peter Rosin --- drivers/i2c/muxes/i2c-mux-pca954x.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/i2c/muxes/i2c-mux-pca954x.c b/drivers/i2c/muxes/i2c-mux-pca954x.c index dd18b9ccb1f4..bbf088e08d73 100644 --- a/drivers/i2c/muxes/i2c-mux-pca954x.c +++ b/drivers/i2c/muxes/i2c-mux-pca954x.c @@ -84,6 +84,11 @@ static const struct chip_desc chips[] = { .enable = 0x4, .muxtype = pca954x_ismux, }, + [pca_9542] = { + .nchans = 2, + .enable = 0x4, + .muxtype = pca954x_ismux, + }, [pca_9543] = { .nchans = 2, .muxtype = pca954x_isswi, @@ -110,7 +115,7 @@ static const struct chip_desc chips[] = { static const struct i2c_device_id pca954x_id[] = { { "pca9540", pca_9540 }, - { "pca9542", pca_9540 }, + { "pca9542", pca_9542 }, { "pca9543", pca_9543 }, { "pca9544", pca_9544 }, { "pca9545", pca_9545 }, @@ -124,7 +129,7 @@ MODULE_DEVICE_TABLE(i2c, pca954x_id); #ifdef CONFIG_ACPI static const struct acpi_device_id pca954x_acpi_ids[] = { { .id = "PCA9540", .driver_data = pca_9540 }, - { .id = "PCA9542", .driver_data = pca_9540 }, + { .id = "PCA9542", .driver_data = pca_9542 }, { .id = "PCA9543", .driver_data = pca_9543 }, { .id = "PCA9544", .driver_data = pca_9544 }, { .id = "PCA9545", .driver_data = pca_9545 }, From 9aedcc61ed101b4dbb7fa7013deca4a7ed7ff418 Mon Sep 17 00:00:00 2001 From: Phil Reid Date: Wed, 25 Jan 2017 09:31:07 +0800 Subject: [PATCH 2/3] dt: bindings: i2c-mux-pca954x: Add documentation for interrupt controller Various muxes can aggregate multiple irq lines and provide a control register to determine the active line. Add bindings for interrupt controller support. Acked-by: Rob Herring Signed-off-by: Phil Reid Signed-off-by: Peter Rosin --- .../devicetree/bindings/i2c/i2c-mux-pca954x.txt | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt b/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt index cf53d5fba20a..aa097045a10e 100644 --- a/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt +++ b/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt @@ -19,7 +19,14 @@ Optional Properties: - i2c-mux-idle-disconnect: Boolean; if defined, forces mux to disconnect all children in idle state. This is necessary for example, if there are several multiplexers on the bus and the devices behind them use same I2C addresses. - + - interrupt-parent: Phandle for the interrupt controller that services + interrupts for this device. + - interrupts: Interrupt mapping for IRQ. + - interrupt-controller: Marks the device node as an interrupt controller. + - #interrupt-cells : Should be two. + - first cell is the pin number + - second cell is used to specify flags. + See also Documentation/devicetree/bindings/interrupt-controller/interrupts.txt Example: @@ -29,6 +36,11 @@ Example: #size-cells = <0>; reg = <0x74>; + interrupt-parent = <&ipic>; + interrupts = <17 IRQ_TYPE_LEVEL_LOW>; + interrupt-controller; + #interrupt-cells = <2>; + i2c@2 { #address-cells = <1>; #size-cells = <0>; From f2114795f721bd5028284ddf84b150798a9b7a73 Mon Sep 17 00:00:00 2001 From: Phil Reid Date: Wed, 25 Jan 2017 09:31:08 +0800 Subject: [PATCH 3/3] i2c: mux: pca954x: Add interrupt controller support 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. Signed-off-by: Phil Reid Signed-off-by: Peter Rosin --- 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 bbf088e08d73..06fd9cc85b23 100644 --- a/drivers/i2c/muxes/i2c-mux-pca954x.c +++ b/drivers/i2c/muxes/i2c-mux-pca954x.c @@ -41,14 +41,20 @@ #include #include #include +#include +#include #include #include #include +#include #include #include +#include #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 @@ static const struct chip_desc chips[] = { [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 = 0; + + 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;