gpio: add ETRAXFS GPIO driver

Add a GPIO driver for the General I/O block on Axis ETRAX FS SoCs.

Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 176 insertions, 0 deletions

diff --git a/drivers/gpio/gpio-etraxfs.c b/drivers/gpio/gpio-etraxfs.c
new file mode 100644
index 000000000000..28071f4a5672
--- /dev/null
+++ b/drivers/gpio/gpio-etraxfs.c
@@ -0,0 +1,176 @@
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/gpio.h>
+#include <linux/of_gpio.h>
+#include <linux/io.h>
+#include <linux/platform_device.h>
+#include <linux/basic_mmio_gpio.h>
+
+#define ETRAX_FS_rw_pa_dout     0
+#define ETRAX_FS_r_pa_din       4
+#define ETRAX_FS_rw_pa_oe       8
+#define ETRAX_FS_rw_intr_cfg    12
+#define ETRAX_FS_rw_intr_mask   16
+#define ETRAX_FS_rw_ack_intr    20
+#define ETRAX_FS_r_intr         24
+#define ETRAX_FS_rw_pb_dout     32
+#define ETRAX_FS_r_pb_din       36
+#define ETRAX_FS_rw_pb_oe       40
+#define ETRAX_FS_rw_pc_dout     48
+#define ETRAX_FS_r_pc_din       52
+#define ETRAX_FS_rw_pc_oe       56
+#define ETRAX_FS_rw_pd_dout     64
+#define ETRAX_FS_r_pd_din       68
+#define ETRAX_FS_rw_pd_oe       72
+#define ETRAX_FS_rw_pe_dout     80
+#define ETRAX_FS_r_pe_din       84
+#define ETRAX_FS_rw_pe_oe       88
+
+struct etraxfs_gpio_port {
+        const char *label;
+        unsigned int oe;
+        unsigned int dout;
+        unsigned int din;
+        unsigned int ngpio;
+};
+
+struct etraxfs_gpio_info {
+        unsigned int num_ports;
+        const struct etraxfs_gpio_port *ports;
+};
+
+static const struct etraxfs_gpio_port etraxfs_gpio_etraxfs_ports[] = {
+        {
+                .label  = "A",
+                .ngpio  = 8,
+                .oe     = ETRAX_FS_rw_pa_oe,
+                .dout   = ETRAX_FS_rw_pa_dout,
+                .din    = ETRAX_FS_r_pa_din,
+        },
+        {
+                .label  = "B",
+                .ngpio  = 18,
+                .oe     = ETRAX_FS_rw_pb_oe,
+                .dout   = ETRAX_FS_rw_pb_dout,
+                .din    = ETRAX_FS_r_pb_din,
+        },
+        {
+                .label  = "C",
+                .ngpio  = 18,
+                .oe     = ETRAX_FS_rw_pc_oe,
+                .dout   = ETRAX_FS_rw_pc_dout,
+                .din    = ETRAX_FS_r_pc_din,
+        },
+        {
+                .label  = "D",
+                .ngpio  = 18,
+                .oe     = ETRAX_FS_rw_pd_oe,
+                .dout   = ETRAX_FS_rw_pd_dout,
+                .din    = ETRAX_FS_r_pd_din,
+        },
+        {
+                .label  = "E",
+                .ngpio  = 18,
+                .oe     = ETRAX_FS_rw_pe_oe,
+                .dout   = ETRAX_FS_rw_pe_dout,
+                .din    = ETRAX_FS_r_pe_din,
+        },
+};
+
+static const struct etraxfs_gpio_info etraxfs_gpio_etraxfs = {
+        .num_ports = ARRAY_SIZE(etraxfs_gpio_etraxfs_ports),
+        .ports = etraxfs_gpio_etraxfs_ports,
+};
+
+static int etraxfs_gpio_of_xlate(struct gpio_chip *gc,
+                               const struct of_phandle_args *gpiospec,
+                               u32 *flags)
+{
+        /*
+         * Port numbers are A to E, and the properties are integers, so we
+         * specify them as 0xA - 0xE.
+         */
+        if (gc->label[0] - 'A' + 0xA != gpiospec->args[2])
+                return -EINVAL;
+
+        return of_gpio_simple_xlate(gc, gpiospec, flags);
+}
+
+static const struct of_device_id etraxfs_gpio_of_table[] = {
+        {
+                .compatible = "axis,etraxfs-gio",
+                .data = &etraxfs_gpio_etraxfs,
+        },
+        {},
+};
+
+static int etraxfs_gpio_probe(struct platform_device *pdev)
+{
+        struct device *dev = &pdev->dev;
+        const struct etraxfs_gpio_info *info;
+        const struct of_device_id *match;
+        struct bgpio_chip *chips;
+        struct resource *res;
+        void __iomem *regs;
+        int ret;
+        int i;
+
+        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        regs = devm_ioremap_resource(dev, res);
+        if (!regs)
+                return -ENOMEM;
+
+        match = of_match_node(etraxfs_gpio_of_table, dev->of_node);
+        if (!match)
+                return -EINVAL;
+
+        info = match->data;
+
+        chips = devm_kzalloc(dev, sizeof(*chips) * info->num_ports, GFP_KERNEL);
+        if (!chips)
+                return -ENOMEM;
+
+        for (i = 0; i < info->num_ports; i++) {
+                struct bgpio_chip *bgc = &chips[i];
+                const struct etraxfs_gpio_port *port = &info->ports[i];
+
+                ret = bgpio_init(bgc, dev, 4,
+                                 regs + port->din,      /* dat */
+                                 regs + port->dout,     /* set */
+                                 NULL,                  /* clr */
+                                 regs + port->oe,       /* dirout */
+                                 NULL,                  /* dirin */
+                                 BGPIOF_UNREADABLE_REG_SET);
+                if (ret)
+                        return ret;
+
+                bgc->gc.ngpio = port->ngpio;
+                bgc->gc.label = port->label;
+
+                bgc->gc.of_node = dev->of_node;
+                bgc->gc.of_gpio_n_cells = 3;
+                bgc->gc.of_xlate = etraxfs_gpio_of_xlate;
+
+                ret = gpiochip_add(&bgc->gc);
+                if (ret)
+                        dev_err(dev, "Unable to register port %s\n",
+                                bgc->gc.label);
+        }
+
+        return 0;
+}
+
+static struct platform_driver etraxfs_gpio_driver = {
+        .driver = {
+                .name           = "etraxfs-gpio",
+                .of_match_table = of_match_ptr(etraxfs_gpio_of_table),
+        },
+        .probe  = etraxfs_gpio_probe,
+};
+
+static int __init etraxfs_gpio_init(void)
+{
+        return platform_driver_register(&etraxfs_gpio_driver);
+}
+
+device_initcall(etraxfs_gpio_init);