[PATCH V3 2/2] gpio: add STA2X11 GPIO block

From: Alessandro Rubini
Date: Thu Apr 12 2012 - 04:49:17 EST

This introduces 128 gpio bits (for each PCI device installed) with
working interrupt support.

Signed-off-by: Alessandro Rubini <rubini@xxxxxxxxx>
Acked-by: Giancarlo Asnaghi <giancarlo.asnaghi@xxxxxx>
Cc: Alan Cox <alan@xxxxxxxxxxxxxxx>
---
drivers/gpio/Kconfig | 8 +
drivers/gpio/Makefile | 1 +
drivers/gpio/gpio-sta2x11.c | 435 +++++++++++++++++++++++++++++++++++++++++++
3 files changed, 444 insertions(+), 0 deletions(-)
create mode 100644 drivers/gpio/gpio-sta2x11.c

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 7875c3f..d2dbd1d 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -153,6 +153,14 @@ config GPIO_PXA
help
Say yes here to support the PXA GPIO device

+config GPIO_STA2X11
+ bool "STA2x11/ConneXt GPIO support"
+ depends on MFD_STA2X11
+ select GENERIC_IRQ_CHIP
+ help
+ Say yes here to support the STA2x11/ConneXt GPIO device.
+ The GPIO module has 128 GPIO pins with alternate functions.
+
config GPIO_XILINX
bool "Xilinx GPIO support"
depends on PPC_OF || MICROBLAZE
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 1c2f6c0..fb749b1 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -49,6 +49,7 @@ obj-$(CONFIG_PLAT_SAMSUNG) += gpio-samsung.o
obj-$(CONFIG_ARCH_SA1100) += gpio-sa1100.o
obj-$(CONFIG_GPIO_SCH) += gpio-sch.o
obj-$(CONFIG_GPIO_SODAVILLE) += gpio-sodaville.o
+obj-$(CONFIG_GPIO_STA2X11) += gpio-sta2x11.o
obj-$(CONFIG_GPIO_STMPE) += gpio-stmpe.o
obj-$(CONFIG_GPIO_SX150X) += gpio-sx150x.o
obj-$(CONFIG_GPIO_TC3589X) += gpio-tc3589x.o
diff --git a/drivers/gpio/gpio-sta2x11.c b/drivers/gpio/gpio-sta2x11.c
new file mode 100644
index 0000000..38416be
--- /dev/null
+++ b/drivers/gpio/gpio-sta2x11.c
@@ -0,0 +1,435 @@
+/*
+ * STMicroelectronics ConneXt (STA2X11) GPIO driver
+ *
+ * Copyright 2012 ST Microelectronics (Alessandro Rubini)
+ * Based on gpio-ml-ioh.c, Copyright 2010 OKI Semiconductors Ltd.
+ * Also based on previous sta2x11 work, Copyright 2011 Wind River Systems, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 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, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/gpio.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/pci.h>
+#include <linux/platform_device.h>
+#include <linux/mfd/sta2x11-mfd.h>
+
+struct gsta_regs {
+ u32 dat; /* 0x00 */
+ u32 dats;
+ u32 datc;
+ u32 pdis;
+ u32 dir; /* 0x10 */
+ u32 dirs;
+ u32 dirc;
+ u32 unused_1c;
+ u32 afsela; /* 0x20 */
+ u32 unused_24[7];
+ u32 rimsc; /* 0x40 */
+ u32 fimsc;
+ u32 is;
+ u32 ic;
+};
+
+struct gsta_gpio {
+ spinlock_t lock;
+ struct device *dev;
+ void __iomem *reg_base;
+ struct gsta_regs __iomem *regs[GSTA_NR_BLOCKS];
+ struct gpio_chip gpio;
+ int irq_base;
+ /* FIXME: save the whole config here (AF, ...) */
+ unsigned irq_type[GSTA_NR_GPIO];
+};
+
+static inline struct gsta_regs __iomem *__regs(struct gsta_gpio *chip, int nr)
+{
+ return chip->regs[nr / GSTA_GPIO_PER_BLOCK];
+}
+
+static inline u32 __bit(int nr)
+{
+ return 1U << (nr % GSTA_GPIO_PER_BLOCK);
+}
+
+/*
+ * gpio methods
+ */
+
+static void gsta_gpio_set(struct gpio_chip *gpio, unsigned nr, int val)
+{
+ struct gsta_gpio *chip = container_of(gpio, struct gsta_gpio, gpio);
+ struct gsta_regs __iomem *regs = __regs(chip, nr);
+ u32 bit = __bit(nr);
+
+ if (val)
+ writel(bit, &regs->dats);
+ else
+ writel(bit, &regs->datc);
+}
+
+static int gsta_gpio_get(struct gpio_chip *gpio, unsigned nr)
+{
+ struct gsta_gpio *chip = container_of(gpio, struct gsta_gpio, gpio);
+ struct gsta_regs __iomem *regs = __regs(chip, nr);
+ u32 bit = __bit(nr);
+
+ return readl(&regs->dat) & bit;
+}
+
+static int gsta_gpio_direction_output(struct gpio_chip *gpio, unsigned nr,
+ int val)
+{
+ struct gsta_gpio *chip = container_of(gpio, struct gsta_gpio, gpio);
+ struct gsta_regs __iomem *regs = __regs(chip, nr);
+ u32 bit = __bit(nr);
+
+ writel(bit, &regs->dirs);
+ /* Data register after direction, otherwise pullup/down is selected */
+ if (val)
+ writel(bit, &regs->dats);
+ else
+ writel(bit, &regs->datc);
+ return 0;
+}
+
+static int gsta_gpio_direction_input(struct gpio_chip *gpio, unsigned nr)
+{
+ struct gsta_gpio *chip = container_of(gpio, struct gsta_gpio, gpio);
+ struct gsta_regs __iomem *regs = __regs(chip, nr);
+ u32 bit = __bit(nr);
+
+ writel(bit, &regs->dirc);
+ return 0;
+}
+
+static int gsta_gpio_to_irq(struct gpio_chip *gpio, unsigned offset)
+{
+ struct gsta_gpio *chip = container_of(gpio, struct gsta_gpio, gpio);
+ return chip->irq_base + offset;
+}
+
+static void gsta_gpio_setup(struct gsta_gpio *chip) /* called from probe */
+{
+ struct gpio_chip *gpio = &chip->gpio;
+
+ /*
+ * ARCH_NR_GPIOS is currently 256 and dynamic allocation starts
+ * from the end. However, for compatibility, we need the first
+ * ConneXt device to start from gpio 0: it's the main chipset
+ * on most boards so documents and drivers assume gpio0..gpio127
+ */
+ static int gpio_base;
+
+ gpio->label = dev_name(chip->dev);
+ gpio->owner = THIS_MODULE;
+ gpio->direction_input = gsta_gpio_direction_input;
+ gpio->get = gsta_gpio_get;
+ gpio->direction_output = gsta_gpio_direction_output;
+ gpio->set = gsta_gpio_set;
+ gpio->dbg_show = NULL;
+ gpio->base = gpio_base;
+ gpio->ngpio = GSTA_NR_GPIO;
+ gpio->can_sleep = 0;
+ gpio->to_irq = gsta_gpio_to_irq;
+
+ /*
+ * After the first device, turn to dynamic gpio numbers.
+ * For example, with ARCH_NR_GPIOS = 256 we can fit two cards
+ */
+ if (!gpio_base)
+ gpio_base = -1;
+}
+
+/*
+ * Special method: alternate functions and pullup/pulldown. This is only
+ * invoked on startup to configure gpio's according to platform data.
+ * FIXME : this functionality shall be managed (and exported to other drivers)
+ * via the pin control subsystem.
+ */
+static void gsta_set_config(struct gsta_gpio *chip, int nr, unsigned cfg)
+{
+ struct gsta_regs __iomem *regs = __regs(chip, nr);
+ unsigned long flags;
+ u32 bit = __bit(nr);
+ u32 val;
+ int err = 0;
+
+ pr_info("%s: %p %i %i\n", __func__, chip, nr, cfg);
+
+ if (cfg == PINMUX_TYPE_NONE)
+ return;
+
+ /* Alternate function or not? */
+ spin_lock_irqsave(&chip->lock, flags);
+ val = readl(&regs->afsela);
+ if (cfg == PINMUX_TYPE_FUNCTION)
+ val |= bit;
+ else
+ val &= ~bit;
+ writel(val | bit, &regs->afsela);
+ if (cfg == PINMUX_TYPE_FUNCTION) {
+ spin_unlock_irqrestore(&chip->lock, flags);
+ return;
+ }
+
+ /* not alternate function: set details */
+ switch (cfg) {
+ case PINMUX_TYPE_OUTPUT_LOW:
+ writel(bit, &regs->dirs);
+ writel(bit, &regs->datc);
+ break;
+ case PINMUX_TYPE_OUTPUT_HIGH:
+ writel(bit, &regs->dirs);
+ writel(bit, &regs->dats);
+ break;
+ case PINMUX_TYPE_INPUT:
+ writel(bit, &regs->dirc);
+ val = readl(&regs->pdis) | bit;
+ writel(val, &regs->pdis);
+ break;
+ case PINMUX_TYPE_INPUT_PULLUP:
+ writel(bit, &regs->dirc);
+ val = readl(&regs->pdis) & ~bit;
+ writel(val, &regs->pdis);
+ writel(bit, &regs->dats);
+ break;
+ case PINMUX_TYPE_INPUT_PULLDOWN:
+ writel(bit, &regs->dirc);
+ val = readl(&regs->pdis) & ~bit;
+ writel(val, &regs->pdis);
+ writel(bit, &regs->datc);
+ break;
+ default:
+ err = 1;
+ }
+ spin_unlock_irqrestore(&chip->lock, flags);
+ if (err)
+ pr_err("%s: chip %p, pin %i, cfg %i is invalid\n",
+ __func__, chip, nr, cfg);
+}
+
+/*
+ * Irq methods
+ */
+
+static void gsta_irq_disable(struct irq_data *data)
+{
+ struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data);
+ struct gsta_gpio *chip = gc->private;
+ int nr = data->irq - chip->irq_base;
+ struct gsta_regs __iomem *regs = __regs(chip, nr);
+ u32 bit = __bit(nr);
+ u32 val;
+ unsigned long flags;
+
+ spin_lock_irqsave(&chip->lock, flags);
+ if (chip->irq_type[nr] & IRQ_TYPE_EDGE_RISING) {
+ val = readl(&regs->rimsc) & ~bit;
+ writel(val, &regs->rimsc);
+ }
+ if (chip->irq_type[nr] & IRQ_TYPE_EDGE_FALLING) {
+ val = readl(&regs->fimsc) & ~bit;
+ writel(val, &regs->fimsc);
+ }
+ spin_unlock_irqrestore(&chip->lock, flags);
+ return;
+}
+
+static void gsta_irq_enable(struct irq_data *data)
+{
+ struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data);
+ struct gsta_gpio *chip = gc->private;
+ int nr = data->irq - chip->irq_base;
+ struct gsta_regs __iomem *regs = __regs(chip, nr);
+ u32 bit = __bit(nr);
+ u32 val;
+ int type;
+ unsigned long flags;
+
+ type = chip->irq_type[nr];
+
+ spin_lock_irqsave(&chip->lock, flags);
+ val = readl(&regs->rimsc);
+ if (type & IRQ_TYPE_EDGE_RISING)
+ writel(val | bit, &regs->rimsc);
+ else
+ writel(val & ~bit, &regs->rimsc);
+ val = readl(&regs->rimsc);
+ if (type & IRQ_TYPE_EDGE_FALLING)
+ writel(val | bit, &regs->fimsc);
+ else
+ writel(val & ~bit, &regs->fimsc);
+ spin_unlock_irqrestore(&chip->lock, flags);
+ return;
+}
+
+static int gsta_irq_type(struct irq_data *d, unsigned int type)
+{
+ struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+ struct gsta_gpio *chip = gc->private;
+ int nr = d->irq - chip->irq_base;
+
+ /* We only support edge interrupts */
+ if (!(type & (IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING))) {
+ pr_debug("%s: unsupported type 0x%x\n", __func__, type);
+ return -EINVAL;
+ }
+
+ chip->irq_type[nr] = type; /* used for enable/disable */
+
+ gsta_irq_enable(d);
+ return 0;
+}
+
+static irqreturn_t gsta_gpio_handler(int irq, void *dev_id)
+{
+ struct gsta_gpio *chip = dev_id;
+ struct gsta_regs __iomem *regs;
+ u32 is;
+ int i, nr, base;
+ irqreturn_t ret = IRQ_NONE;
+
+ for (i = 0; i < GSTA_NR_BLOCKS; i++) {
+ regs = chip->regs[i];
+ base = chip->irq_base + i * GSTA_GPIO_PER_BLOCK;
+ while ((is = readl(&regs->is))) {
+ nr = __ffs(is);
+ irq = base + nr;
+ generic_handle_irq(irq);
+ writel(1 << nr, &regs->ic);
+ ret = IRQ_HANDLED;
+ }
+ }
+ return ret;
+}
+
+static __devinit void gsta_alloc_irq_chip(struct gsta_gpio *chip)
+{
+ struct irq_chip_generic *gc;
+ struct irq_chip_type *ct;
+
+ gc = irq_alloc_generic_chip(KBUILD_MODNAME, 1, chip->irq_base,
+ chip->reg_base, handle_simple_irq);
+ gc->private = chip;
+ ct = gc->chip_types;
+
+ ct->chip.irq_set_type = gsta_irq_type;
+ ct->chip.irq_disable = gsta_irq_disable;
+ ct->chip.irq_enable = gsta_irq_enable;
+
+ /* FIXME: this makes at most 32 interrupts. Request 0 by now */
+ irq_setup_generic_chip(gc, 0 /* IRQ_MSK(GSTA_GPIO_PER_BLOCK) */, 0,
+ IRQ_NOREQUEST | IRQ_NOPROBE, 0);
+
+ /* Set up all all 128 interrupts: code from setup_generic_chip */
+ {
+ struct irq_chip_type *ct = gc->chip_types;
+ int i, j;
+ for (j = 0; j < GSTA_NR_GPIO; j++) {
+ i = chip->irq_base + j;
+ irq_set_chip_and_handler(i, &ct->chip, ct->handler);
+ irq_set_chip_data(i, gc);
+ irq_modify_status(i, IRQ_NOREQUEST | IRQ_NOPROBE, 0);
+ }
+ gc->irq_cnt = i - gc->irq_base;
+ }
+}
+
+/* The platform device used here is instantiated by the MFD device */
+static int __devinit gsta_probe(struct platform_device *dev)
+{
+ int i, err;
+ struct pci_dev *pdev;
+ struct sta2x11_gpio_pdata *gpio_pdata;
+ struct gsta_gpio *chip;
+ struct resource *res;
+
+ pdev = *(struct pci_dev **)(dev->dev.platform_data);
+ gpio_pdata = dev_get_platdata(&pdev->dev);
+
+ if (gpio_pdata == NULL)
+ dev_err(&dev->dev, "no gpio config\n");
+ pr_debug("gpio config: %p\n", gpio_pdata);
+
+ res = platform_get_resource(dev, IORESOURCE_MEM, 0);
+
+ chip = devm_kzalloc(&dev->dev, sizeof(*chip), GFP_KERNEL);
+ chip->dev = &dev->dev;
+ chip->reg_base = devm_request_and_ioremap(&dev->dev, res);
+
+ for (i = 0; i < GSTA_NR_BLOCKS; i++) {
+ chip->regs[i] = chip->reg_base + i * 4096;
+ /* disable all irqs */
+ writel(0, &chip->regs[i]->rimsc);
+ writel(0, &chip->regs[i]->fimsc);
+ writel(~0, &chip->regs[i]->ic);
+ }
+ spin_lock_init(&chip->lock);
+ gsta_gpio_setup(chip);
+ for (i = 0; i < GSTA_NR_GPIO; i++)
+ gsta_set_config(chip, i, gpio_pdata->pinconfig[i]);
+
+ /* 384 was used in previous code: be compatible for other drivers */
+ err = irq_alloc_descs(-1, 384, GSTA_NR_GPIO, NUMA_NO_NODE);
+ if (err < 0) {
+ dev_warn(&dev->dev, "sta2x11 gpio: Can't get irq base (%i)\n",
+ -err);
+ return err;
+ }
+ chip->irq_base = err;
+ gsta_alloc_irq_chip(chip);
+
+ err = request_irq(pdev->irq, gsta_gpio_handler,
+ IRQF_SHARED, KBUILD_MODNAME, chip);
+ if (err < 0) {
+ dev_err(&dev->dev, "sta2x11 gpio: Can't request irq (%i)\n",
+ -err);
+ goto err_free_descs;
+ }
+
+ err = gpiochip_add(&chip->gpio);
+ if (err < 0) {
+ dev_err(&dev->dev, "sta2x11 gpio: Can't register (%i)\n",
+ -err);
+ goto err_free_irq;
+ }
+
+ platform_set_drvdata(dev, chip);
+ return 0;
+
+err_free_irq:
+ free_irq(pdev->irq, chip);
+err_free_descs:
+ irq_free_descs(chip->irq_base, GSTA_NR_GPIO);
+ return err;
+}
+
+static struct platform_driver sta2x11_gpio_platform_driver = {
+ .driver = {
+ .name = "sta2x11-gpio",
+ .owner = THIS_MODULE,
+ },
+ .probe = gsta_probe,
+};
+
+module_platform_driver(sta2x11_gpio_platform_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("sta2x11_gpio GPIO driver");
--
1.7.7.2
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