MFD and GPIO for STA2X11

+config MFD_STA2X11
+       bool "STA2X11 multi function device support"
+       depends on STA2X11
+       select MFD_CORE
+       select GPIO_STA2X11

drivers/mfd/Kconfig +4 -0

+/*
+ * What follows is the PCI device that hosts the above two pdevs.
+ * Each logic block is 4kB and they are all consecutive: we use this info.
+ */

drivers/mfd/Kconfig +17 -0

+static int __devinit sta2x11_mfd_probe(struct pci_dev *pdev,
+				       const struct pci_device_id *pci_id)
+{
+	int err, i;
+	struct sta2x11_gpio_pdata *gpio_data;
+
+	dev_info(&pdev->dev, "%s\n", __func__);
+
+	err = pci_enable_device(pdev);
+	if (err) {
+		dev_err(&pdev->dev, "Can't enable device.\n");
+		return err;
+	}
+
+	err = pci_enable_msi(pdev);
+	if (err)
+		dev_info(&pdev->dev, "Enable msi failed\n");

drivers/mfd/Kconfig +28 -0

+	/* platform data is the pci device for all of them */
+	for (i = 0; i < ARRAY_SIZE(sta2x11_mfd_bar0); i++) {
+		sta2x11_mfd_bar0[i].pdata_size = sizeof(pdev);
+		sta2x11_mfd_bar0[i].platform_data = &pdev;
+	}
+	sta2x11_mfd_bar1[0].pdata_size = sizeof(pdev);
+	sta2x11_mfd_bar1[0].platform_data = &pdev;
+
+	/* Record this pdev before mfd_add_devices: their probe looks for it */
+	sta2x11_mfd_add(pdev, GFP_ATOMIC);
+
+
+	err = mfd_add_devices(&pdev->dev, -1,
+			      sta2x11_mfd_bar0,
+			      ARRAY_SIZE(sta2x11_mfd_bar0),
+			      &pdev->resource[0],
+			      0);
+	if (err) {
+		dev_err(&pdev->dev, "mfd_add_devices[0] failed: %d\n", err);
+		goto err_disable;
+	}
+
+	err = mfd_add_devices(&pdev->dev, -1,
+			      sta2x11_mfd_bar1,
+			      ARRAY_SIZE(sta2x11_mfd_bar1),
+			      &pdev->resource[1],
+			      0);
+	if (err) {

A few minor comments, since it seems you're going to re-spin this one:

drivers/gpio/gpio-sta2x11.c new file +7 -0

+/*
+ * Special method: alternate functions and pullup/pulldown. This will
+ * need to be exported to other drivers, adding a way to retrieve
+ * the gsta_gpio structure from their own pci device
+ */
+void gsta_set_config(struct gsta_gpio *chip, int nr, unsigned cfg)
+{

+       if (cfg == PINMUX_TYPE_NONE)

+       if (cfg == PINMUX_TYPE_FUNCTION)

+       if (cfg == PINMUX_TYPE_FUNCTION) {

+       case PINMUX_TYPE_OUTPUT_LOW:

+       case PINMUX_TYPE_OUTPUT_HIGH:

+       case PINMUX_TYPE_INPUT:

+       case PINMUX_TYPE_INPUT_PULLUP:

+       case PINMUX_TYPE_INPUT_PULLDOWN:

We have created the pin control subsystem to handle things like this. (Muxing and complex control.)

Quoted 1 line

+ if (cfg == PINMUX_TYPE_FUNCTION) {

(...)

Quoted 1 line

+ case PINMUX_TYPE_OUTPUT_LOW:

(...)

Quoted 1 line

+ case PINMUX_TYPE_OUTPUT_HIGH:

(...)

Quoted 1 line

+ case PINMUX_TYPE_INPUT:

(...)

Quoted 1 line

+ case PINMUX_TYPE_INPUT_PULLUP:

(...)

Quoted 1 line

+ case PINMUX_TYPE_INPUT_PULLDOWN:

We have created the pin control subsystem to handle things like this. (Muxing and complex control.)

Please create a driver in drivers/pinctrl/pinctrl-sta2x11.c that expose both a pinctrl and a GPIOlib interface. The GPIOlib interface can call into the pin control portions just fine.

Quoted 15 lines

Quoted 1 line

+       if (cfg == PINMUX_TYPE_FUNCTION) {

(...)

Quoted 1 line

+       case PINMUX_TYPE_OUTPUT_LOW:

(...)

Quoted 1 line

+       case PINMUX_TYPE_OUTPUT_HIGH:

(...)

Quoted 1 line

+       case PINMUX_TYPE_INPUT:

(...)

Quoted 1 line

+       case PINMUX_TYPE_INPUT_PULLUP:

(...)

Quoted 1 line

+       case PINMUX_TYPE_INPUT_PULLDOWN:

We have created the pin control subsystem to handle things like this. (Muxing and complex control.)

Quoted 3 lines

Please create a driver in drivers/pinctrl/pinctrl-sta2x11.c that expose both a pinctrl and a GPIOlib interface. The GPIOlib interface can call into the pin control portions just fine.

I'm sorry, after digging in it for a while I'm really lost.  This pinctrl file should be there _instead_ of the gpio file or in addition to it?  I see tegra has both, but u300 has only one.

Also, this pinctrl depends on CONFIG_EXPERIMENTAL at this point in time. Is it wise the make the whole sta2x11 thing depend on experimental?

+        * 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->base = 0;

[Nitpick: spelling]

drivers/gpio/gpio-sta2x11.c line 148

Quoted 2 lines

drivers/gpio/gpio-sta2x11.c new file +2 -0

+       gpio->base = gpio_base;
+       gpio->base = 0;

What are you doing here?

The GPIO pin number space is global and you need to be able to handle the case where several controllers of this kind are plugged in, will you not?

Make sure that the global GPIO numberspace is properly handled on these systems, alas I am a bit worried that this may not be that very easy.

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

Signed-off-by Alessandro Rubini <[email protected]>

Acked-by Giancarlo Asnaghi <[email protected]>

Cc Alan Cox <[email protected]>

---
 drivers/gpio/Kconfig        |    9 +
 drivers/gpio/Makefile       |    1 +
 drivers/gpio/gpio-sta2x11.c |  443 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 453 insertions(+), 0 deletions(-)
 create mode 100644 drivers/gpio/gpio-sta2x11.c

drivers/gpio/Kconfig +8 -0

index dbb1909..dbae9c2 100644
@@ -149,6 +149,14 @@ 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

drivers/gpio/Makefile +1 -0

index 593bdcd..f72313d 100644
@@ -47,6 +47,7 @@ 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

drivers/gpio/gpio-sta2x11.c new file +44 -0

new file mode 100644
index 0000000..f1885f4
@@ -0,0 +1,443 @@
+/*
+ * 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 */

drivers/gpio/gpio-sta2x11.c new file +55 -0

+	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;

drivers/gpio/gpio-sta2x11.c new file +46 -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 compatiility, 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->base = 0;
+	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.
+	 * With ARCH_NR_GPIOS = 256 we can fit for example two steval cards
+	 */
+	if (!gpio_base)
+		gpio_base = 1;
+}
+
+/*
+ * Special method: alternate functions and pullup/pulldown. This will
+ * need to be exported to other drivers, adding a way to retrieve
+ * the gsta_gpio structure from their own pci device

drivers/gpio/gpio-sta2x11.c new file +52 -0

+
+	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);
+}

drivers/gpio/gpio-sta2x11.c new file +129 -0

+	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);

drivers/gpio/gpio-sta2x11.c new file +10 -0

+	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++)

drivers/gpio/gpio-sta2x11.c new file +31 -0

+
+	if (err < 0) {
+		dev_warn(&dev->dev, "sta2x11 gpio: Can't get irq base (%i)\n",
+			 -err);
+		goto err_out;
+	}
+	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_out;
+	}
+
+	platform_set_drvdata(dev, chip);
+	return 0;
+
+err_out:
+	if (chip->irq_base > 0)
+		irq_free_descs(chip->irq_base, GSTA_NR_GPIO);
+	kfree(chip);
+	return err;
+}
+
+static struct platform_driver sta2x11_gpio_platform_driver = {
+	.driver = {
+		.name	= "sta2x11-gpio",
+		.owner	= THIS_MODULE,

drivers/gpio/gpio-sta2x11.c new file +3 -0

+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("sta2x11_gpio GPIO driver");

Signature · 1 line

1.7.7.2

drivers/gpio/gpio-sta2x11.c line 399

Quoted 2 lines

drivers/gpio/gpio-sta2x11.c new file +2 -0

+	/* 384 was used in previous code: be compatible for other drivers */
+	err = irq_alloc_descs(-1, 384, GSTA_NR_GPIO, NUMA_NO_NODE);

That's a lot of irqs. Will they all be used?

How do other drivers determine which irq number to use (is it statically assigned, or is there a dynamic mechanism)? If only a portion are used, then the irq_domain linear mapping would be a win here.