gpio: Add APM X-Gene standby GPIO controller driver

Driver for standby GPIO controller of APM X-Gene SoCs on arm64.

Signed-off-by: Y Vo <yvo@apm.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

3 files changed, 169 insertions, 0 deletions

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 8dcd0bd5b0fa..4187fcbc88fd 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -367,6 +367,14 @@ config GPIO_XGENE
           the generic flash controller's address and data pins. Say yes
           here to enable the GFC GPIO functionality.
 
+config GPIO_XGENE_SB
+        tristate "APM X-Gene GPIO standby controller support"
+        depends on ARCH_XGENE && OF_GPIO
+        select GPIO_GENERIC
+        help
+          This driver supports the GPIO block within the APM X-Gene
+          Standby Domain. Say yes here to enable the GPIO functionality.
+
 config GPIO_XILINX
         tristate "Xilinx GPIO support"
         depends on OF_GPIO && (PPC_OF || MICROBLAZE || ARCH_ZYNQ || X86)
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 81755f1305e6..3031b19f06ba 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -105,6 +105,7 @@ obj-$(CONFIG_GPIO_WM831X)	+= gpio-wm831x.o
 obj-$(CONFIG_GPIO_WM8350)       += gpio-wm8350.o
 obj-$(CONFIG_GPIO_WM8994)       += gpio-wm8994.o
 obj-$(CONFIG_GPIO_XGENE)        += gpio-xgene.o
+obj-$(CONFIG_GPIO_XGENE_SB)     += gpio-xgene-sb.o
 obj-$(CONFIG_GPIO_XILINX)       += gpio-xilinx.o
 obj-$(CONFIG_GPIO_XTENSA)       += gpio-xtensa.o
 obj-$(CONFIG_GPIO_ZEVIO)        += gpio-zevio.o
diff --git a/drivers/gpio/gpio-xgene-sb.c b/drivers/gpio/gpio-xgene-sb.c
new file mode 100644
index 000000000000..b6a15c39293e
--- /dev/null
+++ b/drivers/gpio/gpio-xgene-sb.c
@@ -0,0 +1,160 @@
+/*
+ * AppliedMicro X-Gene SoC GPIO-Standby Driver
+ *
+ * Copyright (c) 2014, Applied Micro Circuits Corporation
+ * Author:      Tin Huynh <tnhuynh@apm.com>.
+ *              Y Vo <yvo@apm.com>.
+ *
+ * This program is free software; you can redistribute  it and/or modify it
+ * under  the terms of  the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/module.h>
+#include <linux/io.h>
+#include <linux/platform_device.h>
+#include <linux/of_gpio.h>
+#include <linux/gpio.h>
+#include <linux/gpio/driver.h>
+#include <linux/basic_mmio_gpio.h>
+
+#define XGENE_MAX_GPIO_DS               22
+#define XGENE_MAX_GPIO_DS_IRQ           6
+
+#define GPIO_MASK(x)                    (1U << ((x) % 32))
+
+#define MPA_GPIO_INT_LVL                0x0290
+#define MPA_GPIO_OE_ADDR                0x029c
+#define MPA_GPIO_OUT_ADDR               0x02a0
+#define MPA_GPIO_IN_ADDR                0x02a4
+#define MPA_GPIO_SEL_LO                 0x0294
+
+/**
+ * struct xgene_gpio_sb - GPIO-Standby private data structure.
+ * @bgc:                        memory-mapped GPIO controllers.
+ * @irq:                        Mapping GPIO pins and interrupt number
+ * nirq:                        Number of GPIO pins that supports interrupt
+ */
+struct xgene_gpio_sb {
+        struct bgpio_chip       bgc;
+        u32 *irq;
+        u32 nirq;
+};
+
+static inline struct xgene_gpio_sb *to_xgene_gpio_sb(struct gpio_chip *gc)
+{
+        struct bgpio_chip *bgc = to_bgpio_chip(gc);
+
+        return container_of(bgc, struct xgene_gpio_sb, bgc);
+}
+
+static void xgene_gpio_set_bit(struct bgpio_chip *bgc, void __iomem *reg, u32 gpio, int val)
+{
+        u32 data;
+
+        data = bgc->read_reg(reg);
+        if (val)
+                data |= GPIO_MASK(gpio);
+        else
+                data &= ~GPIO_MASK(gpio);
+        bgc->write_reg(reg, data);
+}
+
+static int apm_gpio_sb_to_irq(struct gpio_chip *gc, u32 gpio)
+{
+        struct xgene_gpio_sb *priv = to_xgene_gpio_sb(gc);
+
+        if (priv->irq[gpio])
+                return priv->irq[gpio];
+
+        return -ENXIO;
+}
+
+static int xgene_gpio_sb_probe(struct platform_device *pdev)
+{
+        struct xgene_gpio_sb *priv;
+        u32 ret, i;
+        u32 default_lines[] = {0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D};
+        struct resource *res;
+        void __iomem *regs;
+
+        priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+        if (!priv)
+                return -ENOMEM;
+
+        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        regs = devm_ioremap_resource(&pdev->dev, res);
+        if (!regs)
+                return PTR_ERR(regs);
+
+        ret = bgpio_init(&priv->bgc, &pdev->dev, 4,
+                        regs + MPA_GPIO_IN_ADDR,
+                        regs + MPA_GPIO_OUT_ADDR, NULL,
+                        regs + MPA_GPIO_OE_ADDR, NULL, 0);
+        if (ret)
+                return ret;
+
+        priv->bgc.gc.to_irq = apm_gpio_sb_to_irq;
+        priv->bgc.gc.ngpio = XGENE_MAX_GPIO_DS;
+
+        priv->nirq = XGENE_MAX_GPIO_DS_IRQ;
+
+        priv->irq = devm_kzalloc(&pdev->dev, sizeof(u32) * XGENE_MAX_GPIO_DS,
+                                   GFP_KERNEL);
+        if (!priv->irq)
+                return -ENOMEM;
+        memset(priv->irq, 0, sizeof(u32) * XGENE_MAX_GPIO_DS);
+
+        for (i = 0; i < priv->nirq; i++) {
+                priv->irq[default_lines[i]] = platform_get_irq(pdev, i);
+                xgene_gpio_set_bit(&priv->bgc, regs + MPA_GPIO_SEL_LO,
+                                   default_lines[i] * 2, 1);
+                xgene_gpio_set_bit(&priv->bgc, regs + MPA_GPIO_INT_LVL, i, 1);
+        }
+
+        platform_set_drvdata(pdev, priv);
+
+        ret = gpiochip_add(&priv->bgc.gc);
+        if (ret)
+                dev_err(&pdev->dev, "failed to register X-Gene GPIO Standby driver\n");
+        else
+                dev_info(&pdev->dev, "X-Gene GPIO Standby driver registered\n");
+
+        return ret;
+}
+
+static int xgene_gpio_sb_remove(struct platform_device *pdev)
+{
+        struct xgene_gpio_sb *priv = platform_get_drvdata(pdev);
+
+        return bgpio_remove(&priv->bgc);
+}
+
+static const struct of_device_id xgene_gpio_sb_of_match[] = {
+        {.compatible = "apm,xgene-gpio-sb", },
+        {},
+};
+MODULE_DEVICE_TABLE(of, xgene_gpio_sb_of_match);
+
+static struct platform_driver xgene_gpio_sb_driver = {
+        .driver = {
+                   .name = "xgene-gpio-sb",
+                   .of_match_table = xgene_gpio_sb_of_match,
+                   },
+        .probe = xgene_gpio_sb_probe,
+        .remove = xgene_gpio_sb_remove,
+};
+module_platform_driver(xgene_gpio_sb_driver);
+
+MODULE_AUTHOR("AppliedMicro");
+MODULE_DESCRIPTION("APM X-Gene GPIO Standby driver");
+MODULE_LICENSE("GPL");