diff --git a/Documentation/devicetree/bindings/i2c/i2c-arb-gpio-challenge.txt b/Documentation/devicetree/bindings/i2c/i2c-arb-gpio-challenge.txt index 71191ff0e781..248a155414c2 100644 --- a/Documentation/devicetree/bindings/i2c/i2c-arb-gpio-challenge.txt +++ b/Documentation/devicetree/bindings/i2c/i2c-arb-gpio-challenge.txt @@ -44,8 +44,7 @@ Required properties: - our-claim-gpio: The GPIO that we use to claim the bus. - their-claim-gpios: The GPIOs that the other sides use to claim the bus. Note that some implementations may only support a single other master. -- Standard I2C mux properties. See i2c-mux.txt in this directory. -- Single I2C child bus node at reg 0. See i2c-mux.txt in this directory. +- I2C arbitration bus node. See i2c-arb.txt in this directory. Optional properties: - slew-delay-us: microseconds to wait for a GPIO to go high. Default is 10 us. @@ -63,8 +62,6 @@ Example: i2c-arbitrator { compatible = "i2c-arb-gpio-challenge"; - #address-cells = <1>; - #size-cells = <0>; i2c-parent = <&{/i2c@12CA0000}>; @@ -74,8 +71,7 @@ Example: wait-retry-us = <3000>; wait-free-us = <50000>; - i2c@0 { - reg = <0>; + i2c-arb { #address-cells = <1>; #size-cells = <0>; diff --git a/Documentation/devicetree/bindings/i2c/i2c-arb.txt b/Documentation/devicetree/bindings/i2c/i2c-arb.txt new file mode 100644 index 000000000000..59abf9277bdc --- /dev/null +++ b/Documentation/devicetree/bindings/i2c/i2c-arb.txt @@ -0,0 +1,35 @@ +Common i2c arbitration bus properties. + +- i2c-arb child node + +Required properties for the i2c-arb child node: +- #address-cells = <1>; +- #size-cells = <0>; + +Optional properties for i2c-arb child node: +- Child nodes conforming to i2c bus binding + + +Example : + + /* + An NXP pca9541 I2C bus master selector at address 0x74 + with a NXP pca8574 GPIO expander attached. + */ + + arb@74 { + compatible = "nxp,pca9541"; + reg = <0x74>; + + i2c-arb { + #address-cells = <1>; + #size-cells = <0>; + + gpio@38 { + compatible = "nxp,pca8574"; + reg = <0x38>; + #gpio-cells = <2>; + gpio-controller; + }; + }; + }; diff --git a/Documentation/devicetree/bindings/i2c/i2c-gate.txt b/Documentation/devicetree/bindings/i2c/i2c-gate.txt new file mode 100644 index 000000000000..1846d236e656 --- /dev/null +++ b/Documentation/devicetree/bindings/i2c/i2c-gate.txt @@ -0,0 +1,41 @@ +An i2c gate is useful to e.g. reduce the digital noise for RF tuners connected +to the i2c bus. Gates are similar to arbitrators in that you need to perform +some kind of operation to access the i2c bus past the arbitrator/gate, but +there are no competing masters to consider for gates and therefore there is +no arbitration happening for gates. + +Common i2c gate properties. + +- i2c-gate child node + +Required properties for the i2c-gate child node: +- #address-cells = <1>; +- #size-cells = <0>; + +Optional properties for i2c-gate child node: +- Child nodes conforming to i2c bus binding + + +Example : + + /* + An Invensense mpu9150 at address 0x68 featuring an on-chip Asahi + Kasei ak8975 compass behind a gate. + */ + + mpu9150@68 { + compatible = "invensense,mpu9150"; + reg = <0x68>; + interrupt-parent = <&gpio1>; + interrupts = <18 1>; + + i2c-gate { + #address-cells = <1>; + #size-cells = <0>; + + ax8975@c { + compatible = "ak,ak8975"; + reg = <0x0c>; + }; + }; + }; diff --git a/Documentation/devicetree/bindings/i2c/i2c-mux.txt b/Documentation/devicetree/bindings/i2c/i2c-mux.txt index af84cce5cd7b..212e6779dc5c 100644 --- a/Documentation/devicetree/bindings/i2c/i2c-mux.txt +++ b/Documentation/devicetree/bindings/i2c/i2c-mux.txt @@ -2,19 +2,32 @@ Common i2c bus multiplexer/switch properties. An i2c bus multiplexer/switch will have several child busses that are numbered uniquely in a device dependent manner. The nodes for an i2c bus -multiplexer/switch will have one child node for each child -bus. +multiplexer/switch will have one child node for each child bus. -Required properties: +Optional properties: +- #address-cells = <1>; + This property is required is the i2c-mux child node does not exist. + +- #size-cells = <0>; + This property is required is the i2c-mux child node does not exist. + +- i2c-mux + For i2c multiplexers/switches that have child nodes that are a mixture + of both i2c child busses and other child nodes, the 'i2c-mux' subnode + can be used for populating the i2c child busses. If an 'i2c-mux' + subnode is present, only subnodes of this will be considered as i2c + child busses. + +Required properties for the i2c-mux child node: - #address-cells = <1>; - #size-cells = <0>; -Required properties for child nodes: +Required properties for i2c child bus nodes: - #address-cells = <1>; - #size-cells = <0>; - reg : The sub-bus number. -Optional properties for child nodes: +Optional properties for i2c child bus nodes: - Other properties specific to the multiplexer/switch hardware. - Child nodes conforming to i2c bus binding diff --git a/Documentation/devicetree/bindings/i2c/nxp,pca9541.txt b/Documentation/devicetree/bindings/i2c/nxp,pca9541.txt new file mode 100644 index 000000000000..0fbbc6970ec5 --- /dev/null +++ b/Documentation/devicetree/bindings/i2c/nxp,pca9541.txt @@ -0,0 +1,29 @@ +* NXP PCA9541 I2C bus master selector + +Required Properties: + + - compatible: Must be "nxp,pca9541" + + - reg: The I2C address of the device. + + The following required properties are defined externally: + + - I2C arbitration bus node. See i2c-arb.txt in this directory. + + +Example: + + i2c-arbitrator@74 { + compatible = "nxp,pca9541"; + reg = <0x74>; + + i2c-arb { + #address-cells = <1>; + #size-cells = <0>; + + eeprom@54 { + compatible = "at,24c08"; + reg = <0x54>; + }; + }; + }; diff --git a/MAINTAINERS b/MAINTAINERS index 4b9a6ae6aaf9..c58ee8c0b782 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -5675,6 +5675,8 @@ S: Maintained F: Documentation/i2c/i2c-topology F: Documentation/i2c/muxes/ F: Documentation/devicetree/bindings/i2c/i2c-mux* +F: Documentation/devicetree/bindings/i2c/i2c-arb* +F: Documentation/devicetree/bindings/i2c/i2c-gate* F: drivers/i2c/i2c-mux.c F: drivers/i2c/muxes/ F: include/linux/i2c-mux.h diff --git a/drivers/i2c/i2c-mux.c b/drivers/i2c/i2c-mux.c index 764f195795e4..90f59c088750 100644 --- a/drivers/i2c/i2c-mux.c +++ b/drivers/i2c/i2c-mux.c @@ -255,6 +255,10 @@ struct i2c_mux_core *i2c_mux_alloc(struct i2c_adapter *parent, muxc->dev = dev; if (flags & I2C_MUX_LOCKED) muxc->mux_locked = true; + if (flags & I2C_MUX_ARBITRATOR) + muxc->arbitrator = true; + if (flags & I2C_MUX_GATE) + muxc->gate = true; muxc->select = select; muxc->deselect = deselect; muxc->max_adapters = max_adapters; @@ -335,18 +339,42 @@ int i2c_mux_add_adapter(struct i2c_mux_core *muxc, * nothing if !CONFIG_OF. */ if (muxc->dev->of_node) { - struct device_node *child; + struct device_node *dev_node = muxc->dev->of_node; + struct device_node *mux_node, *child = NULL; u32 reg; - for_each_child_of_node(muxc->dev->of_node, child) { - ret = of_property_read_u32(child, "reg", ®); - if (ret) - continue; - if (chan_id == reg) { - priv->adap.dev.of_node = child; - break; + if (muxc->arbitrator) + mux_node = of_get_child_by_name(dev_node, "i2c-arb"); + else if (muxc->gate) + mux_node = of_get_child_by_name(dev_node, "i2c-gate"); + else + mux_node = of_get_child_by_name(dev_node, "i2c-mux"); + + if (mux_node) { + /* A "reg" property indicates an old-style DT entry */ + if (!of_property_read_u32(mux_node, "reg", ®)) { + of_node_put(mux_node); + mux_node = NULL; } } + + if (!mux_node) + mux_node = of_node_get(dev_node); + else if (muxc->arbitrator || muxc->gate) + child = of_node_get(mux_node); + + if (!child) { + for_each_child_of_node(mux_node, child) { + ret = of_property_read_u32(child, "reg", ®); + if (ret) + continue; + if (chan_id == reg) + break; + } + } + + priv->adap.dev.of_node = child; + of_node_put(mux_node); } /* diff --git a/drivers/i2c/muxes/i2c-arb-gpio-challenge.c b/drivers/i2c/muxes/i2c-arb-gpio-challenge.c index a90bbc4037dd..86fc2d4c081b 100644 --- a/drivers/i2c/muxes/i2c-arb-gpio-challenge.c +++ b/drivers/i2c/muxes/i2c-arb-gpio-challenge.c @@ -130,7 +130,7 @@ static int i2c_arbitrator_probe(struct platform_device *pdev) return -EINVAL; } - muxc = i2c_mux_alloc(NULL, dev, 1, sizeof(*arb), 0, + muxc = i2c_mux_alloc(NULL, dev, 1, sizeof(*arb), I2C_MUX_ARBITRATOR, i2c_arbitrator_select, i2c_arbitrator_deselect); if (!muxc) return -ENOMEM; diff --git a/drivers/i2c/muxes/i2c-mux-pca9541.c b/drivers/i2c/muxes/i2c-mux-pca9541.c index 3cb8af635db5..4ea7e691afc7 100644 --- a/drivers/i2c/muxes/i2c-mux-pca9541.c +++ b/drivers/i2c/muxes/i2c-mux-pca9541.c @@ -85,6 +85,13 @@ static const struct i2c_device_id pca9541_id[] = { MODULE_DEVICE_TABLE(i2c, pca9541_id); +#ifdef CONFIG_OF +static const struct of_device_id pca9541_of_match[] = { + { .compatible = "nxp,pca9541" }, + {} +}; +#endif + /* * Write to chip register. Don't use i2c_transfer()/i2c_smbus_xfer() * as they will try to lock the adapter a second time. @@ -349,7 +356,8 @@ static int pca9541_probe(struct i2c_client *client, force = 0; if (pdata) force = pdata->modes[0].adap_id; - muxc = i2c_mux_alloc(adap, &client->dev, 1, sizeof(*data), 0, + muxc = i2c_mux_alloc(adap, &client->dev, 1, sizeof(*data), + I2C_MUX_ARBITRATOR, pca9541_select_chan, pca9541_release_chan); if (!muxc) return -ENOMEM; @@ -382,6 +390,7 @@ static int pca9541_remove(struct i2c_client *client) static struct i2c_driver pca9541_driver = { .driver = { .name = "pca9541", + .of_match_table = of_match_ptr(pca9541_of_match), }, .probe = pca9541_probe, .remove = pca9541_remove, diff --git a/drivers/i2c/muxes/i2c-mux-pca954x.c b/drivers/i2c/muxes/i2c-mux-pca954x.c index 528e755c468f..6dfd31ba29a0 100644 --- a/drivers/i2c/muxes/i2c-mux-pca954x.c +++ b/drivers/i2c/muxes/i2c-mux-pca954x.c @@ -42,6 +42,7 @@ #include #include #include +#include #include #include @@ -58,14 +59,6 @@ enum pca_type { pca_9548, }; -struct pca954x { - enum pca_type type; - - u8 last_chan; /* last register value */ - u8 deselect; - struct i2c_client *client; -}; - struct chip_desc { u8 nchans; u8 enable; /* used for muxes only */ @@ -75,6 +68,14 @@ struct chip_desc { } muxtype; }; +struct pca954x { + const struct chip_desc *chip; + + u8 last_chan; /* last register value */ + u8 deselect; + struct i2c_client *client; +}; + /* Provide specs for the PCA954x types we know about */ static const struct chip_desc chips[] = { [pca_9540] = { @@ -119,6 +120,20 @@ static const struct i2c_device_id pca954x_id[] = { }; MODULE_DEVICE_TABLE(i2c, pca954x_id); +#ifdef CONFIG_OF +static const struct of_device_id pca954x_of_match[] = { + { .compatible = "nxp,pca9540", .data = &chips[pca_9540] }, + { .compatible = "nxp,pca9542", .data = &chips[pca_9542] }, + { .compatible = "nxp,pca9543", .data = &chips[pca_9543] }, + { .compatible = "nxp,pca9544", .data = &chips[pca_9544] }, + { .compatible = "nxp,pca9545", .data = &chips[pca_9545] }, + { .compatible = "nxp,pca9546", .data = &chips[pca_9546] }, + { .compatible = "nxp,pca9547", .data = &chips[pca_9547] }, + { .compatible = "nxp,pca9548", .data = &chips[pca_9548] }, + {} +}; +#endif + /* Write to mux register. Don't use i2c_transfer()/i2c_smbus_xfer() for this as they will try to lock adapter a second time */ static int pca954x_reg_write(struct i2c_adapter *adap, @@ -151,7 +166,7 @@ static int pca954x_select_chan(struct i2c_mux_core *muxc, u32 chan) { struct pca954x *data = i2c_mux_priv(muxc); struct i2c_client *client = data->client; - const struct chip_desc *chip = &chips[data->type]; + const struct chip_desc *chip = data->chip; u8 regval; int ret = 0; @@ -197,6 +212,7 @@ static int pca954x_probe(struct i2c_client *client, int num, force, class; struct i2c_mux_core *muxc; struct pca954x *data; + const struct of_device_id *match; int ret; if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_BYTE)) @@ -226,14 +242,19 @@ static int pca954x_probe(struct i2c_client *client, return -ENODEV; } - data->type = id->driver_data; + match = of_match_device(of_match_ptr(pca954x_of_match), &client->dev); + if (match) + data->chip = of_device_get_match_data(&client->dev); + else + data->chip = &chips[id->driver_data]; + data->last_chan = 0; /* force the first selection */ idle_disconnect_dt = of_node && of_property_read_bool(of_node, "i2c-mux-idle-disconnect"); /* Now create an adapter for each channel */ - for (num = 0; num < chips[data->type].nchans; num++) { + for (num = 0; num < data->chip->nchans; num++) { bool idle_disconnect_pd = false; force = 0; /* dynamic adap number */ @@ -263,7 +284,7 @@ static int pca954x_probe(struct i2c_client *client, dev_info(&client->dev, "registered %d multiplexed busses for I2C %s %s\n", - num, chips[data->type].muxtype == pca954x_ismux + num, data->chip->muxtype == pca954x_ismux ? "mux" : "switch", client->name); return 0; @@ -299,6 +320,7 @@ static struct i2c_driver pca954x_driver = { .driver = { .name = "pca954x", .pm = &pca954x_pm, + .of_match_table = of_match_ptr(pca954x_of_match), }, .probe = pca954x_probe, .remove = pca954x_remove, diff --git a/include/linux/i2c-mux.h b/include/linux/i2c-mux.h index d4c1d12f900d..bd74d5706f3b 100644 --- a/include/linux/i2c-mux.h +++ b/include/linux/i2c-mux.h @@ -32,7 +32,9 @@ struct i2c_mux_core { struct i2c_adapter *parent; struct device *dev; - bool mux_locked; + unsigned int mux_locked:1; + unsigned int arbitrator:1; + unsigned int gate:1; void *priv; @@ -51,7 +53,9 @@ struct i2c_mux_core *i2c_mux_alloc(struct i2c_adapter *parent, int (*deselect)(struct i2c_mux_core *, u32)); /* flags for i2c_mux_alloc */ -#define I2C_MUX_LOCKED BIT(0) +#define I2C_MUX_LOCKED BIT(0) +#define I2C_MUX_ARBITRATOR BIT(1) +#define I2C_MUX_GATE BIT(2) static inline void *i2c_mux_priv(struct i2c_mux_core *muxc) {