Message-ID: <20070513214007.GA24163@lixom.net>
Date:	Sun, 13 May 2007 16:40:07 -0500
From:	olof@...om.net (Olof Johansson)
To:	Christoph Hellwig <hch@...radead.org>,
	linux-pcmcia@...ts.infradead.org, akpm@...l.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2] pcmcia: export pcmcia_bus_type

Hi,

On Sun, May 13, 2007 at 10:20:42PM +0100, Christoph Hellwig wrote:
> On Sat, May 12, 2007 at 01:06:58PM -0500, Olof Johansson wrote:
> > Export pcmcia_bus_type so module-based drivers can register bus notifiers,
> > and add it to what seems to be the main include file.
> 
> This all sounds rather fishy to me.  Care to send the code along that makes
> use of it.

Sure. I was planning on sending the code that uses this on Friday but
ran out of time. Also, given the other discussions regarding I/O space
and mappings, I need to rework it so I ended up holding back until I
had time to do that.

I use the notifier hooks to fix up the ->archdata.dma_ops for the devices
added. Maybe there's an easier way to do it that I'm missing.

Current patch included below, note that it's not not 100% cleaned up.

> And even if we're going to add the export it should be _GPL because it's
> a deeply internal implementation detail.  Then again I'm not exactly
> convinced we should export it yet.

Other buses already export it (i.e. PCI).  Also, other symbols in the
drivers were exported non-_GPL so I went with that. I'll be happy to
switch to the other kind of export if needed. Seems like PCI exports it
non-_GPL as well.


-Olof




Driver for the CompactFlash slot on the PA Semi Electra eval board. It's
a simple device sitting on localbus, with interrupts and detect/voltage
control over GPIO.

The driver is implemented as an of_platform driver, and adds localbus
as a bus being probed by the of_platform framework.


Signed-off-by: Olof Johansson <olof@...om.net>

---

This patch depends on the PCMCIA pcmcia_bus_type export to compile:

http://lists.infradead.org/pipermail/linux-pcmcia/2007-May/004613.html

and on the ioaddr_t + ioport_map changes to work at runtime:

http://patchwork.ozlabs.org/linuxppc/patch?id=11092
http://patchwork.ozlabs.org/linuxppc/patch?id=11093

Index: 2.6.21/drivers/pcmcia/Kconfig
===================================================================
--- 2.6.21.orig/drivers/pcmcia/Kconfig
+++ 2.6.21/drivers/pcmcia/Kconfig
@@ -270,6 +270,13 @@ config AT91_CF
 	  Say Y here to support the CompactFlash controller on AT91 chips.
 	  Or choose M to compile the driver as a module named "at91_cf".
 
+config ELECTRA_CF
+	tristate "Electra CompactFlash Controller"
+	depends on PCMCIA && PPC_PASEMI
+	help
+	  Say Y here to support the CompactFlash controller on the
+	  PA Semi Electra eval board.
+
 config PCCARD_NONSTATIC
 	tristate
 
Index: 2.6.21/drivers/pcmcia/Makefile
===================================================================
--- 2.6.21.orig/drivers/pcmcia/Makefile
+++ 2.6.21/drivers/pcmcia/Makefile
@@ -37,6 +37,7 @@ obj-$(CONFIG_PCMCIA_VRC4171)			+= vrc417
 obj-$(CONFIG_PCMCIA_VRC4173)			+= vrc4173_cardu.o
 obj-$(CONFIG_OMAP_CF)				+= omap_cf.o
 obj-$(CONFIG_AT91_CF)				+= at91_cf.o
+obj-$(CONFIG_ELECTRA_CF)			+= electra_cf.o
 
 sa11xx_core-y					+= soc_common.o sa11xx_base.o
 pxa2xx_core-y					+= soc_common.o pxa2xx_base.o
Index: 2.6.21/drivers/pcmcia/electra_cf.c
===================================================================
--- /dev/null
+++ 2.6.21/drivers/pcmcia/electra_cf.c
@@ -0,0 +1,393 @@
+/*
+ * Copyright (C) 2007 PA Semi, Inc
+ *
+ * Maintained by: Olof Johansson <olof@...om.net>
+ *
+ * Based on drivers/pcmcia/omap_cf.c
+ *
+ * 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, 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/sched.h>
+#include <linux/platform_device.h>
+#include <linux/platform_device.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+
+#include <pcmcia/ss.h>
+#include <asm/of_platform.h>
+
+static const char driver_name[] = "electra-cf";
+
+struct electra_cf_socket {
+	struct pcmcia_socket	socket;
+
+	struct timer_list	timer;
+	unsigned		present:1;
+	unsigned		active:1;
+
+	struct of_device	*ofdev;
+	unsigned long		mem_phys;
+	void __iomem *		mem_base;
+	unsigned long		mem_size;
+	unsigned long		io_phys;
+	void __iomem *		io_base;
+	unsigned long		io_size;
+	u_int			irq;
+	struct resource		iomem;
+	void __iomem *		gpio_base;
+	int			gpio_detect;
+	int			gpio_vsense;
+	int			gpio_3v;
+	int			gpio_5v;
+};
+
+#define	POLL_INTERVAL		(2 * HZ)
+
+
+static int electra_cf_present(struct electra_cf_socket *cf)
+{
+	unsigned int gpio;
+
+	gpio = in_le32(cf->gpio_base+0x40);
+	return !(gpio & (1 << cf->gpio_detect));
+}
+
+static int electra_cf_ss_init(struct pcmcia_socket *s)
+{
+	return 0;
+}
+
+/* the timer is primarily to kick this socket's pccardd */
+static void electra_cf_timer(unsigned long _cf)
+{
+	struct electra_cf_socket *cf = (void *) _cf;
+	int present = electra_cf_present(cf);
+
+	if (present != cf->present) {
+		cf->present = present;
+		pcmcia_parse_events(&cf->socket, SS_DETECT);
+	}
+
+	if (cf->active)
+		mod_timer(&cf->timer, jiffies + POLL_INTERVAL);
+}
+
+static irqreturn_t electra_cf_irq(int irq, void *_cf)
+{
+	electra_cf_timer((unsigned long)_cf);
+	return IRQ_HANDLED;
+}
+
+static int electra_cf_get_status(struct pcmcia_socket *s, u_int *sp)
+{
+	struct electra_cf_socket *cf;
+
+	if (!sp)
+		return -EINVAL;
+
+	cf = container_of(s, struct electra_cf_socket, socket);
+
+	/* NOTE CF is always 3VCARD */
+	if (electra_cf_present(cf)) {
+		struct electra_cf_socket *cf;
+
+		*sp = SS_READY | SS_DETECT | SS_POWERON | SS_3VCARD;
+		cf = container_of(s, struct electra_cf_socket, socket);
+		s->pci_irq = cf->irq;
+	} else
+		*sp = 0;
+	return 0;
+}
+
+static int electra_cf_set_socket(struct pcmcia_socket *sock,
+				 struct socket_state_t *s)
+{
+	unsigned int gpio;
+	unsigned int vcc;
+	struct electra_cf_socket *cf;
+
+	cf = container_of(sock, struct electra_cf_socket, socket);
+
+	/* "reset" means no power in our case */
+	vcc = (s->flags & SS_RESET) ? 0 : s->Vcc;
+
+	switch (vcc) {
+	case 0:
+		gpio = 0;
+		break;
+	case 33:
+		gpio = (1 << cf->gpio_3v);
+		break;
+	default:
+		/* CF is 3.3V only */
+		return -EINVAL;
+	}
+
+	gpio |= 1 << (cf->gpio_3v + 16); /* enwr */
+	gpio |= 1 << (cf->gpio_5v + 16); /* enwr */
+	out_le32(cf->gpio_base+0x90, gpio);
+
+	pr_debug("%s: Vcc %d, io_irq %d, flags %04x csc %04x\n",
+		driver_name, s->Vcc, s->io_irq, s->flags, s->csc_mask);
+
+	return 0;
+}
+
+static int electra_cf_ss_suspend(struct pcmcia_socket *s)
+{
+	pr_debug("%s: %s\n", driver_name, __FUNCTION__);
+	return electra_cf_set_socket(s, &dead_socket);
+}
+
+static int electra_cf_set_io_map(struct pcmcia_socket *s,
+				 struct pccard_io_map *io)
+{
+	struct electra_cf_socket *cf;
+
+	cf = container_of(s, struct electra_cf_socket, socket);
+	io->flags &= MAP_ACTIVE|MAP_ATTRIB|MAP_16BIT;
+	io->start = (unsigned long)cf->io_base;
+	io->stop = (unsigned long)cf->io_base + 0x800 - 1;
+	return 0;
+}
+
+static int electra_cf_set_mem_map(struct pcmcia_socket *s,
+				  struct pccard_mem_map *map)
+{
+	struct electra_cf_socket *cf;
+
+	if (map->card_start)
+		return -EINVAL;
+	cf = container_of(s, struct electra_cf_socket, socket);
+	map->static_start = cf->mem_phys;
+	map->flags &= MAP_ACTIVE|MAP_ATTRIB|MAP_16BIT;
+	if (!(map->flags & MAP_ATTRIB))
+		map->static_start += 0x800;
+	return 0;
+}
+
+static struct pccard_operations electra_cf_ops = {
+	.init			= electra_cf_ss_init,
+	.suspend		= electra_cf_ss_suspend,
+	.get_status		= electra_cf_get_status,
+	.set_socket		= electra_cf_set_socket,
+	.set_io_map		= electra_cf_set_io_map,
+	.set_mem_map		= electra_cf_set_mem_map,
+};
+
+static int __devinit electra_cf_probe(struct of_device *ofdev,
+				      const struct of_device_id *match)
+{
+	struct device *device = &ofdev->dev;
+	struct device_node *np = ofdev->node;
+	struct electra_cf_socket   *cf;
+	struct resource mem, io;
+	int status;
+	const unsigned int *prop;
+	int err;
+
+	err = of_address_to_resource(np, 0, &mem);
+	if (err)
+		return -EINVAL;
+
+	err = of_address_to_resource(np, 1, &io);
+	if (err)
+		return -EINVAL;
+
+	cf = kzalloc(sizeof *cf, GFP_KERNEL);
+	if (!cf)
+		return -ENOMEM;
+
+	init_timer(&cf->timer);
+	cf->timer.function = electra_cf_timer;
+	cf->timer.data = (unsigned long) cf;
+
+	cf->ofdev = ofdev;
+	cf->mem_phys = mem.start;
+	cf->mem_base = ioremap(mem.start, mem.end - mem.start);
+	cf->io_base = ioremap(io.start, io.end - io.start);
+	cf->gpio_base = ioremap(0xfc103000, 0x1000);
+	dev_set_drvdata(device, cf);
+
+	if (!cf->mem_base || !cf->io_base || !cf->gpio_base) {
+		dev_err(device, "can't ioremap ranges\n");
+		status = -ENOMEM;
+		goto fail1;
+	}
+
+	cf->iomem.start = (unsigned long)cf->io_base;
+	cf->iomem.end = (unsigned long)cf->io_base + (io.end - io.start);
+	cf->iomem.flags = IORESOURCE_MEM;
+
+	cf->irq = irq_of_parse_and_map(np, 0);
+
+	status = request_irq(cf->irq, electra_cf_irq, IRQF_SHARED,
+			     driver_name, cf);
+	if (status < 0) {
+		dev_err(device, "request_irq failed\n");
+		goto fail1;
+	}
+
+	cf->socket.pci_irq = cf->irq;
+
+	prop = get_property(np, "card-detect-gpio", NULL);
+	cf->gpio_detect = *prop;
+	prop = get_property(np, "card-vsense-gpio", NULL);
+	cf->gpio_vsense = *prop;
+	prop = get_property(np, "card-3v-gpio", NULL);
+	cf->gpio_3v = *prop;
+	prop = get_property(np, "card-5v-gpio", NULL);
+	cf->gpio_5v = *prop;
+
+	/* pcmcia layer only remaps "real" memory not iospace */
+	cf->socket.io_offset = (unsigned long)cf->io_base;
+
+	/* reserve chip-select regions */
+	if (!request_mem_region(mem.start, mem.end + 1 - mem.start,
+				driver_name)) {
+		status = -ENXIO;
+		dev_err(device, "Can't claim memory region\n");
+		goto fail1;
+	}
+
+	if (!request_mem_region(io.start, io.end + 1 - io.start,
+				driver_name)) {
+		status = -ENXIO;
+		dev_err(device, "Can't claim I/O region\n");
+		goto fail2;
+	}
+
+	cf->socket.owner = THIS_MODULE;
+	cf->socket.dev.parent = &ofdev->dev;
+	cf->socket.ops = &electra_cf_ops;
+	cf->socket.resource_ops = &pccard_static_ops;
+	cf->socket.features = SS_CAP_PCCARD | SS_CAP_STATIC_MAP |
+				SS_CAP_MEM_ALIGN;
+	cf->socket.map_size = 0x800;
+	cf->socket.io[0].res = &cf->iomem;
+
+	status = pcmcia_register_socket(&cf->socket);
+	if (status < 0) {
+		dev_err(device, "pcmcia_register_socket failed\n");
+		goto fail3;
+	}
+
+	dev_info(device, "at mem 0x%lx io 0x%lx irq %d\n",
+		 mem.start, io.start, cf->irq);
+
+	cf->active = 1;
+	electra_cf_timer((unsigned long)cf);
+	return 0;
+
+fail3:
+	release_mem_region(io.start, io.end + 1 - io.start);
+fail2:
+	release_mem_region(mem.start, mem.end + 1 - mem.start);
+fail1:
+	if (cf->io_base)
+		iounmap(cf->io_base);
+	if (cf->mem_base)
+		iounmap(cf->mem_base);
+	if (cf->gpio_base)
+		iounmap(cf->gpio_base);
+	device_init_wakeup(&ofdev->dev, 0);
+	kfree(cf);
+	return status;
+
+}
+
+static int __devexit electra_cf_remove(struct of_device *ofdev)
+{
+	struct device *device = &ofdev->dev;
+	struct electra_cf_socket *cf;
+
+	cf = dev_get_drvdata(device);
+
+	cf->active = 0;
+	pcmcia_unregister_socket(&cf->socket);
+	del_timer_sync(&cf->timer);
+	free_irq(cf->irq, cf);
+
+	iounmap(cf->io_base);
+	iounmap(cf->mem_base);
+	iounmap(cf->gpio_base);
+	release_mem_region(cf->mem_phys, cf->mem_size);
+	release_region(cf->io_phys, cf->io_size);
+
+	kfree(cf);
+
+	return 0;
+}
+
+static int bus_notify(struct notifier_block *nb, unsigned long action,
+		      void *data)
+{
+	struct device *dev = data;
+
+	pr_debug("bus notify called\n");
+
+	/* We are only intereted in device addition */
+	if (action != BUS_NOTIFY_ADD_DEVICE)
+		return 0;
+
+	/* We use the direct ops for localbus */
+	dev->archdata.dma_ops = &dma_direct_ops;
+
+	return 0;
+}
+
+static struct notifier_block bus_notifier = {
+	.notifier_call = bus_notify,
+};
+
+static struct of_device_id electra_cf_match[] =
+{
+	{
+		.type	   = "electra-cf",
+	},
+	{},
+};
+
+static struct of_platform_driver electra_cf_driver =
+{
+	.name	   = (char *)driver_name,
+	.match_table    = electra_cf_match,
+	.probe	  = electra_cf_probe,
+	.remove   = electra_cf_remove,
+};
+
+static int __init electra_cf_init(void)
+{
+	bus_register_notifier(&pcmcia_bus_type, &bus_notifier);
+	return of_register_platform_driver(&electra_cf_driver);
+}
+module_init(electra_cf_init);
+
+static void __exit electra_cf_exit(void)
+{
+	bus_unregister_notifier(&pcmcia_bus_type, &bus_notifier);
+	of_unregister_platform_driver(&electra_cf_driver);
+}
+module_exit(electra_cf_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR ("Olof Johansson <olof@...om.net>");
+MODULE_DESCRIPTION("PA Semi Electra CF driver");
+
Index: 2.6.21/arch/powerpc/platforms/pasemi/setup.c
===================================================================
--- 2.6.21.orig/arch/powerpc/platforms/pasemi/setup.c
+++ 2.6.21/arch/powerpc/platforms/pasemi/setup.c
@@ -245,6 +245,7 @@ static void __init pas_init_early(void)
 }
 
 static struct of_device_id pasemi_bus_ids[] = {
+	{ .type = "localbus", },
 	{ .type = "sdc", },
 	{},
 };
-
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