G'day Jan,
On 5/06/2018 01:05, Jan Kundrát wrote:
This driver is a bit weird because it can hide several gpio_chip
instances underneath a single SPI slave. One cannot put the
gpio-line-names DT stanza directly to the SPI slave when the
spi-present-mask has more than one bit set.
I'm making up the `gpio-bank` DT child name as well as its `address`
property. We need something to match the DT entries with the SPI
address.
Reviewed-by: Phil Reid <preid@xxxxxxxxxxxxxxxxx>
One comment below
Signed-off-by: Jan Kundrát <jan.kundrat@xxxxxxxxx>
---
.../bindings/pinctrl/pinctrl-mcp23s08.txt | 35 +++++++++++++++++++
drivers/pinctrl/pinctrl-mcp23s08.c | 12 +++++++
2 files changed, 47 insertions(+)
diff --git a/Documentation/devicetree/bindings/pinctrl/pinctrl-mcp23s08.txt b/Documentation/devicetree/bindings/pinctrl/pinctrl-mcp23s08.txt
index a5a8322a31bd..7573df69ccea 100644
--- a/Documentation/devicetree/bindings/pinctrl/pinctrl-mcp23s08.txt
+++ b/Documentation/devicetree/bindings/pinctrl/pinctrl-mcp23s08.txt
@@ -142,3 +142,38 @@ gpio21: gpio@21 {
bias-pull-up;
};
};
+
+Line naming
+===========
+
+Because several gpio_chip instances are hidden below a single device tree
+node, it is necessary to split the names into several child nodes. Ensure
+that the configured addresses match those in the microchip,spi-present-mask:
+
+gpio@0 {
+ compatible = "microchip,mcp23s17";
+ gpio-controller;
+ #gpio-cells = <2>;
+ /* this bitmask has bits #0 (0x01) and #2 (0x04) set */
+ spi-present-mask = <0x05>;
+ reg = <0>;
+ spi-max-frequency = <1000000>;
+
+ gpio-bank@1 {
+ address = <0>;
+ gpio-line-names =
+ "GPA0",
+ "GPA1",
+ ...
+ "GPA7",
+ "GPB0",
+ "GPB1",
+ ...
+ "GPB7";
+ };
+
+ gpio-bank@2 {
+ address = <2>;
+ gpio-line-names = ...
+ };
+};
diff --git a/drivers/pinctrl/pinctrl-mcp23s08.c b/drivers/pinctrl/pinctrl-mcp23s08.c
index bbef9833edb8..c4fac4e1de71 100644
--- a/drivers/pinctrl/pinctrl-mcp23s08.c
+++ b/drivers/pinctrl/pinctrl-mcp23s08.c
@@ -16,6 +16,7 @@
#include <linux/pinctrl/pinctrl.h>
#include <linux/pinctrl/pinconf.h>
#include <linux/pinctrl/pinconf-generic.h>
+#include "../gpio/gpiolib.h"
Perhaps the declaration for devprop_gpiochip_set_names() needs to be moved
to linux/gpio/driver.h
Someone more knowledgeable than me may be able to comment.
/*
* MCP types supported by driver
@@ -1086,6 +1087,7 @@ static int mcp23s08_probe(struct spi_device *spi)
int status, type;
unsigned ngpio = 0;
const struct of_device_id *match;
+ struct device_node *np;
match = of_match_device(of_match_ptr(mcp23s08_spi_of_match), &spi->dev);
if (match)
@@ -1148,6 +1150,16 @@ static int mcp23s08_probe(struct spi_device *spi)
if (pdata->base != -1)
pdata->base += data->mcp[addr]->chip.ngpio;
ngpio += data->mcp[addr]->chip.ngpio;
+
+ for_each_available_child_of_node(spi->dev.of_node, np) {
+ u32 chip_addr;
+ status = of_property_read_u32(np, "address", &chip_addr);
+ if (status)
+ continue;
+ if (chip_addr != addr)
+ continue;
+ devprop_gpiochip_set_names(&data->mcp[addr]->chip, of_fwnode_handle(np));
+ }
}
data->ngpio = ngpio;
--
Regards
Phil
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