Re: [PATCH] Generic platform device IDE driver
From: Paul Mundt
Date: Thu Oct 05 2006 - 05:17:11 EST
On Wed, Oct 04, 2006 at 03:38:45PM +0100, Alan Cox wrote:
> Ar Iau, 2006-10-05 am 05:05 +0900, ysgrifennodd Paul Mundt:
> > Ok, I wasn't sure if libata was intended for anything outside of the
> > SATA case (especially non-PCI), but if that's the way to go, I'll look
> > at hacking something up under libata.
>
> Take a look at 2.6.18-mm or 2.6.19-* and you should see all you need in
> that including the pcmcia driver and other users who set up much the
> same way a generic platform device driver would.
>
Ok, just hacked this together quickly, how does it look? I'm booting
this on an SH-4A (R7780RP) from current git and all works fine..
Thankfully you did most of the heavy lifting :-)
--
drivers/ata/Kconfig | 9 ++
drivers/ata/Makefile | 1
drivers/ata/pata_platform.c | 198 ++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 208 insertions(+)
commit f257da330416413947c65dac20cefbd39231eb30
Author: Paul Mundt <lethal@xxxxxxxxxxxx>
Date: Thu Oct 5 18:13:27 2006 +0900
ata: Simple generic platform device libata driver.
This adds a simple generic libata driver for directly-connected
and pre-configured platform devices commonly found on embedded
systems.
For most of these devices, the only variation ends up being the
I/O and CTL bases as well as the IRQ, with everything else
effectively behaving as a standard ISA bus PIO device.
Users of 'pata_platform' are required to pack in 3 resources per
port, namely, the aforementioned variations. Each port must be
registered independently, which doesn't end up being a big problem,
as most of the embedded use cases don't have more than one or two
ports anyways.
Signed-off-by: Paul Mundt <lethal@xxxxxxxxxxxx>
diff --git a/drivers/ata/Kconfig b/drivers/ata/Kconfig
index 3f4aa0c..70a5a08 100644
--- a/drivers/ata/Kconfig
+++ b/drivers/ata/Kconfig
@@ -482,6 +482,15 @@ config PATA_WINBOND
If unsure, say N.
+config PATA_PLATFORM
+ tristate "Generic platform device PATA support"
+ depends on EMBEDDED
+ help
+ This option enables support for generic directly connected ATA
+ devices commonly found on embedded systems.
+
+ If unsure, say N.
+
endif
endmenu
diff --git a/drivers/ata/Makefile b/drivers/ata/Makefile
index 72243a6..408c8c9 100644
--- a/drivers/ata/Makefile
+++ b/drivers/ata/Makefile
@@ -53,6 +53,7 @@ obj-$(CONFIG_PATA_VIA) += pata_via.o
obj-$(CONFIG_PATA_WINBOND) += pata_sl82c105.o
obj-$(CONFIG_PATA_SIS) += pata_sis.o
obj-$(CONFIG_PATA_TRIFLEX) += pata_triflex.o
+obj-$(CONFIG_PATA_PLATFORM) += pata_platform.o
# Should be last but one libata driver
obj-$(CONFIG_ATA_GENERIC) += ata_generic.o
# Should be last libata driver
diff --git a/drivers/ata/pata_platform.c b/drivers/ata/pata_platform.c
new file mode 100644
index 0000000..b9de610
--- /dev/null
+++ b/drivers/ata/pata_platform.c
@@ -0,0 +1,198 @@
+/*
+ * Generic platform device PATA driver
+ *
+ * Copyright (C) 2006 Paul Mundt
+ *
+ * Based on pata_pcmcia:
+ *
+ * Copyright 2005-2006 Red Hat Inc <alan@xxxxxxxxxx>, all rights reserved.
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/blkdev.h>
+#include <scsi/scsi_host.h>
+#include <linux/ata.h>
+#include <linux/libata.h>
+#include <linux/platform_device.h>
+
+#define DRV_NAME "pata_platform"
+#define DRV_VERSION "0.1.0"
+
+static int pio_mask = 1;
+
+/*
+ * Provide our own set_mode() as we don't want to change anything that has
+ * already been configured..
+ */
+static void pata_platform_set_mode(struct ata_port *ap)
+{
+ int i;
+
+ for (i = 0; i < ATA_MAX_DEVICES; i++) {
+ struct ata_device *dev = &ap->device[i];
+
+ if (ata_dev_enabled(dev)) {
+ /* We don't really care */
+ dev->pio_mode = dev->xfer_mode = XFER_PIO_0;
+ dev->xfer_shift = ATA_SHIFT_PIO;
+ dev->flags |= ATA_DFLAG_PIO;
+ }
+ }
+}
+
+static struct scsi_host_template pata_platform_sht = {
+ .module = THIS_MODULE,
+ .name = DRV_NAME,
+ .ioctl = ata_scsi_ioctl,
+ .queuecommand = ata_scsi_queuecmd,
+ .can_queue = ATA_DEF_QUEUE,
+ .this_id = ATA_SHT_THIS_ID,
+ .sg_tablesize = LIBATA_MAX_PRD,
+ .max_sectors = ATA_MAX_SECTORS,
+ .cmd_per_lun = ATA_SHT_CMD_PER_LUN,
+ .emulated = ATA_SHT_EMULATED,
+ .use_clustering = ATA_SHT_USE_CLUSTERING,
+ .proc_name = DRV_NAME,
+ .dma_boundary = ATA_DMA_BOUNDARY,
+ .slave_configure = ata_scsi_slave_config,
+ .bios_param = ata_std_bios_param,
+};
+
+static struct ata_port_operations pata_platform_port_ops = {
+ .set_mode = pata_platform_set_mode,
+
+ .port_disable = ata_port_disable,
+ .tf_load = ata_tf_load,
+ .tf_read = ata_tf_read,
+ .check_status = ata_check_status,
+ .exec_command = ata_exec_command,
+ .dev_select = ata_std_dev_select,
+
+ .freeze = ata_bmdma_freeze,
+ .thaw = ata_bmdma_thaw,
+ .error_handler = ata_bmdma_error_handler,
+ .post_internal_cmd = ata_bmdma_post_internal_cmd,
+
+ .qc_prep = ata_qc_prep,
+ .qc_issue = ata_qc_issue_prot,
+
+ .data_xfer = ata_pio_data_xfer_noirq,
+
+ .irq_handler = ata_interrupt,
+ .irq_clear = ata_bmdma_irq_clear,
+
+ .port_start = ata_port_start,
+ .port_stop = ata_port_stop,
+ .host_stop = ata_host_stop
+};
+
+/**
+ * pata_platform_probe - attach a platform interface
+ * @pdev: platform device
+ *
+ * Register a platform bus IDE interface. Such interfaces are PIO and we
+ * assume do not support IRQ sharing.
+ *
+ * Platform devices are expected to contain 3 resources per port:
+ *
+ * - I/O Base (IORESOURCE_IO)
+ * - CTL Base (IORESOURCE_IO)
+ * - IRQ (IORESOURCE_IRQ)
+ */
+static int __devinit pata_platform_probe(struct platform_device *pdev)
+{
+ struct resource *io_res, *ctl_res;
+ struct ata_probe_ent ae;
+ int ret = -EBUSY;
+
+ /*
+ * Simple resource validation ..
+ */
+ if (unlikely(pdev->num_resources != 3)) {
+ dev_err(&pdev->dev, "invalid number of resources\n");
+ return -EINVAL;
+ }
+
+ io_res = platform_get_resource(pdev, IORESOURCE_IO, 0);
+ if (unlikely(io_res == NULL))
+ return -EINVAL;
+
+ ctl_res = platform_get_resource(pdev, IORESOURCE_IO, 1);
+ if (unlikely(ctl_res == NULL))
+ return -EINVAL;
+
+ /*
+ * Now that that's out of the way, wire up the port..
+ */
+ memset(&ae, 0, sizeof(struct ata_probe_ent));
+ INIT_LIST_HEAD(&ae.node);
+ ae.dev = &pdev->dev;
+ ae.port_ops = &pata_platform_port_ops;
+ ae.sht = &pata_platform_sht;
+ ae.n_ports = 1;
+ ae.pio_mask = pio_mask;
+ ae.irq = platform_get_irq(pdev, 0);
+ ae.irq_flags = 0;
+ ae.port_flags = ATA_FLAG_SLAVE_POSS | ATA_FLAG_SRST;
+ ae.port[0].cmd_addr = io_res->start;
+ ae.port[0].altstatus_addr = ctl_res->start;
+ ae.port[0].ctl_addr = ctl_res->start;
+ ata_std_ports(&ae.port[0]);
+
+ ret = ata_device_add(&ae);
+ if (unlikely(ret == 0))
+ return -ENODEV;
+
+ return 0;
+}
+
+/**
+ * pata_platform_remove - unplug a platform interface
+ * @pdev: platform device
+ *
+ * A platform bus ATA device has been unplugged. Perform the needed
+ * cleanup. Also called on module unload for any active devices.
+ */
+static int __devexit pata_platform_remove(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct ata_host *host = dev_get_drvdata(dev);
+
+ ata_host_remove(host);
+ dev_set_drvdata(dev, NULL);
+
+ return 0;
+}
+
+static struct platform_driver pata_platform_driver = {
+ .probe = pata_platform_probe,
+ .remove = __devexit_p(pata_platform_remove),
+ .driver = {
+ .name = DRV_NAME,
+ .owner = THIS_MODULE,
+ },
+};
+
+static int __init pata_platform_init(void)
+{
+ return platform_driver_register(&pata_platform_driver);
+}
+
+static void __exit pata_platform_exit(void)
+{
+ platform_driver_unregister(&pata_platform_driver);
+}
+module_init(pata_platform_init);
+module_exit(pata_platform_exit);
+
+module_param(pio_mask, int, 0);
+
+MODULE_AUTHOR("Paul Mundt");
+MODULE_DESCRIPTION("low-level driver for platform device ATA");
+MODULE_LICENSE("GPL");
+MODULE_VERSION(DRV_VERSION);
-
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