[PATCH] [V3] powerpc: Xilinx: PS2: Added new XPS PS2 driver
John Linn
John.Linn at xilinx.com
Thu Jul 10 02:14:06 EST 2008
These look like good comments from Peter.
Dmitry, how would you like to do this, would you prefer us to do an
incremental patch from the existing patch (V3)? Or a new V4 for the
patch?
Peter, with regard to the data sheet, I would prefer not to put a
specific URL in as things always seem to get moved around so anything
beyond xilinx.com would likely be wrong sometime in the future.
Thanks,
John
> -----Original Message-----
> From: Peter Korsgaard [mailto:jacmet at gmail.com] On Behalf Of Peter
Korsgaard
> Sent: Tuesday, July 08, 2008 3:00 AM
> To: John Linn
> Cc: linuxppc-dev at ozlabs.org; linux-input at vger.kernel.org;
grant.likely at secretlab.ca;
> jwboyer at linux.vnet.ibm.com; dmitry.torokhov at gmail.com; Sadanand
Mutyala
> Subject: Re: [PATCH] [V3] powerpc: Xilinx: PS2: Added new XPS PS2
driver
>
> >>>>> "John" == John Linn <john.linn at xilinx.com> writes:
>
> Hi,
>
> > Added a new driver for Xilinx XPS PS2 IP. This driver is
> > a flat driver to better match the Linux driver pattern.
>
> > Signed-off-by: Sadanand <sadanan at xilinx.com>
> > Signed-off-by: John Linn <john.linn at xilinx.com>
> > ---
> > V2
> > Updated the driver based on feedback from Dmitry, Peter, and
Grant.
> > We believe Montavista copyright is still valid.
> > V3
> > Incorporated Dmitry and Grant's 2nd set of comments which were
some
> > minor cleanup and removal of the mutex which was not needed.
>
> > drivers/input/serio/Kconfig | 5 +
> > drivers/input/serio/Makefile | 1 +
> > drivers/input/serio/xilinx_ps2.c | 384
++++++++++++++++++++++++++++++++++++++
> > 3 files changed, 390 insertions(+), 0 deletions(-)
> > create mode 100644 drivers/input/serio/xilinx_ps2.c
>
> > diff --git a/drivers/input/serio/Kconfig
b/drivers/input/serio/Kconfig
> > index ec4b661..0e62b39 100644
> > --- a/drivers/input/serio/Kconfig
> > +++ b/drivers/input/serio/Kconfig
> > @@ -190,4 +190,9 @@ config SERIO_RAW
> > To compile this driver as a module, choose M here: the
> > module will be called serio_raw.
>
> > +config SERIO_XILINX_XPS_PS2
> > + tristate "Xilinx XPS PS/2 Controller Support"
> > + help
> > + This driver supports XPS PS/2 IP from Xilinx EDK.
> > +
> > endif
> > diff --git a/drivers/input/serio/Makefile
b/drivers/input/serio/Makefile
> > index 38b8868..9b6c813 100644
> > --- a/drivers/input/serio/Makefile
> > +++ b/drivers/input/serio/Makefile
> > @@ -21,3 +21,4 @@ obj-$(CONFIG_SERIO_PCIPS2) += pcips2.o
> > obj-$(CONFIG_SERIO_MACEPS2) += maceps2.o
> > obj-$(CONFIG_SERIO_LIBPS2) += libps2.o
> > obj-$(CONFIG_SERIO_RAW) += serio_raw.o
> > +obj-$(CONFIG_SERIO_XILINX_XPS_PS2) += xilinx_ps2.o
> > diff --git a/drivers/input/serio/xilinx_ps2.c
b/drivers/input/serio/xilinx_ps2.c
> > new file mode 100644
> > index 0000000..e86f11b
> > --- /dev/null
> > +++ b/drivers/input/serio/xilinx_ps2.c
> > @@ -0,0 +1,384 @@
> > +/*
> > + * Xilinx XPS PS/2 device driver
> > + *
> > + * (c) 2005 MontaVista Software, Inc.
> > + * (c) 2008 Xilinx, Inc.
> > + *
> > + * 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.
> > + *
> > + * 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.,
> > + * 675 Mass Ave, Cambridge, MA 02139, USA.
> > + */
> > +
> > +
> > +#include <linux/module.h>
> > +#include <linux/serio.h>
> > +#include <linux/interrupt.h>
> > +#include <linux/errno.h>
> > +#include <linux/init.h>
> > +#include <linux/list.h>
> > +#include <linux/io.h>
> > +
> > +#include <linux/of_device.h>
> > +#include <linux/of_platform.h>
> > +
> > +#define DRIVER_NAME "xilinx_ps2"
> > +
>
> Is there an online datasheet available somewhere on xilinx.com? (I
> couldn't find any right away) - If so, please add a link here.
>
> > +/* Register offsets for the xps2 device */
> > +#define XPS2_SRST_OFFSET 0x00000000 /* Software Reset register */
> > +#define XPS2_STATUS_OFFSET 0x00000004 /* Status register */
> > +#define XPS2_RX_DATA_OFFSET 0x00000008 /* Receive Data
register */
> > +#define XPS2_TX_DATA_OFFSET 0x0000000C /* Transmit Data
register */
> > +#define XPS2_GIER_OFFSET 0x0000002C /* Global Interrupt Enable
reg */
> > +#define XPS2_IPISR_OFFSET 0x00000030 /* Interrupt Status register
*/
> > +#define XPS2_IPIER_OFFSET 0x00000038 /* Interrupt Enable register
*/
> > +
> > +/* Reset Register Bit Definitions */
> > +#define XPS2_SRST_RESET 0x0000000A /* Software Reset */
> > +
> > +/* Status Register Bit Positions */
> > +#define XPS2_STATUS_RX_FULL 0x00000001 /* Receive Full */
> > +#define XPS2_STATUS_TX_FULL 0x00000002 /* Transmit Full */
> > +
> > +/* Bit definitions for ISR/IER registers. Both the registers have
the same bit
> > + * definitions and are only defined once. */
> > +#define XPS2_IPIXR_WDT_TOUT 0x00000001 /* Watchdog Timeout
Interrupt */
> > +#define XPS2_IPIXR_TX_NOACK 0x00000002 /* Transmit No ACK
Interrupt */
> > +#define XPS2_IPIXR_TX_ACK 0x00000004 /* Transmit ACK (Data)
Interrupt */
> > +#define XPS2_IPIXR_RX_OVF 0x00000008 /* Receive Overflow Interrupt
*/
> > +#define XPS2_IPIXR_RX_ERR 0x00000010 /* Receive Error Interrupt */
> > +#define XPS2_IPIXR_RX_FULL 0x00000020 /* Receive Data
Interrupt */
> > +
> > +/* Mask for all the Transmit Interrupts */
> > +#define XPS2_IPIXR_TX_ALL (XPS2_IPIXR_TX_NOACK |
XPS2_IPIXR_TX_ACK)
> > +
> > +/* Mask for all the Receive Interrupts */
> > +#define XPS2_IPIXR_RX_ALL (XPS2_IPIXR_RX_OVF | XPS2_IPIXR_RX_ERR |
\
> > + XPS2_IPIXR_RX_FULL)
> > +
> > +/* Mask for all the Interrupts */
> > +#define XPS2_IPIXR_ALL (XPS2_IPIXR_TX_ALL |
XPS2_IPIXR_RX_ALL | \
> > + XPS2_IPIXR_WDT_TOUT)
> > +
> > +/* Global Interrupt Enable mask */
> > +#define XPS2_GIER_GIE_MASK 0x80000000
> > +
> > +struct xps2data {
> > + int irq;
> > + u32 phys_addr;
> > + u32 remap_size;
>
> Do you need to keep track of these? Couldn't you just do an
> of_address_to_resource in the remove to get them? I guess they should
> be resource_size_t instead of u32s as well.
>
>
> > + spinlock_t lock;
> > + u8 rxb; /* Rx buffer */
>
> Why do you need this? It seems like you don't need to keep this value
> between interrupts.
>
> > + void __iomem *base_address; /* virt. address of control
registers */
> > + unsigned int dfl;
>
> flags is maybe a better name. Do you need to keep track of it between
> interrupts?
>
> > + struct serio serio; /* serio */
> > +};
> > +
> > +/************************************/
> > +/* XPS PS/2 data transmission calls */
> > +/************************************/
> > +
> > +/*
> > + * xps2_recv() will attempt to receive a byte of data from the
PS/2 port.
> > + */
> > +static int xps2_recv(struct xps2data *drvdata, u8 *byte)
> > +{
> > + u32 sr;
> > + int status = -1;
> > +
> > + /* If there is data available in the PS/2 receiver, read it */
> > + sr = in_be32(drvdata->base_address + XPS2_STATUS_OFFSET);
> > + if (sr & XPS2_STATUS_RX_FULL) {
> > + *byte = in_be32(drvdata->base_address +
XPS2_RX_DATA_OFFSET);
> > + status = 0;
> > + }
> > +
> > + return status;
> > +}
> > +
> > +/*********************/
> > +/* Interrupt handler */
> > +/*********************/
> > +static irqreturn_t xps2_interrupt(int irq, void *dev_id)
> > +{
> > + struct xps2data *drvdata = (struct xps2data *)dev_id;
>
> The cast isn't needed.
>
> > + u32 intr_sr;
> > + u8 c;
> > + int status;
> > +
> > + /* Get the PS/2 interrupts and clear them */
> > + intr_sr = in_be32(drvdata->base_address + XPS2_IPISR_OFFSET);
> > + out_be32(drvdata->base_address + XPS2_IPISR_OFFSET, intr_sr);
> > +
> > + /* Check which interrupt is active */
> > + if (intr_sr & XPS2_IPIXR_RX_OVF) {
> > + printk(KERN_ERR "%s: receive overrun error\n",
> > + drvdata->serio.name);
> > + }
> > +
> > + if (intr_sr & XPS2_IPIXR_RX_ERR)
> > + drvdata->dfl |= SERIO_PARITY;
> > +
> > + if (intr_sr & (XPS2_IPIXR_TX_NOACK | XPS2_IPIXR_WDT_TOUT))
> > + drvdata->dfl |= SERIO_TIMEOUT;
> > +
> > + if (intr_sr & XPS2_IPIXR_RX_FULL) {
> > + status = xps2_recv(drvdata, &drvdata->rxb);
> > +
> > + /* Error, if a byte is not received */
> > + if (status) {
> > + printk(KERN_ERR
> > + "%s: wrong rcvd byte count (%d)\n",
> > + drvdata->serio.name, status);
> > + } else {
> > + c = drvdata->rxb;
> > + serio_interrupt(&drvdata->serio, c,
drvdata->dfl);
> > + drvdata->dfl = 0;
> > + }
> > + }
> > +
> > + if (intr_sr & XPS2_IPIXR_TX_ACK)
> > + drvdata->dfl = 0;
> > +
> > + return IRQ_HANDLED;
> > +}
> > +
> > +/*******************/
> > +/* serio callbacks */
> > +/*******************/
> > +
> > +/*
> > + * sxps2_write() sends a byte out through the PS/2 interface.
> > + */
> > +static int sxps2_write(struct serio *pserio, unsigned char c)
> > +{
> > + struct xps2data *drvdata = pserio->port_data;
> > + unsigned long flags;
> > + u32 sr;
> > + int status = -1;
> > +
> > + spin_lock_irqsave(&drvdata->lock, flags);
> > + /* If the PS/2 transmitter is empty send a byte of data */
> > + sr = in_be32(drvdata->base_address + XPS2_STATUS_OFFSET);
> > + if ((sr & XPS2_STATUS_TX_FULL) == 0) {
> > + out_be32(drvdata->base_address + XPS2_TX_DATA_OFFSET,
c);
> > + status = 0;
> > + }
> > + spin_unlock_irqrestore(&drvdata->lock, flags);
> > +
> > + return status;
> > +}
> > +
> > +/*
> > + * sxps2_open() is called when a port is open by the higher layer.
>
> s/open/opened/
>
> > + */
> > +static int sxps2_open(struct serio *pserio)
> > +{
> > + struct xps2data *drvdata = pserio->port_data;
> > + int retval;
> > +
> > + retval = request_irq(drvdata->irq, &xps2_interrupt, 0,
> > + DRIVER_NAME, drvdata);
> > + if (retval) {
> > + printk(KERN_ERR
> > + "%s: Couldn't allocate interrupt %d\n",
> > + drvdata->serio.name, drvdata->irq);
>
> please use dev_err here and elsewhere.
>
> > + return retval;
> > + }
> > +
> > + /* start reception by enabling the interrupts */
> > + out_be32(drvdata->base_address + XPS2_GIER_OFFSET,
XPS2_GIER_GIE_MASK);
> > + out_be32(drvdata->base_address + XPS2_IPIER_OFFSET,
XPS2_IPIXR_RX_ALL);
> > + (void)xps2_recv(drvdata, &drvdata->rxb);
> > +
> > + return 0; /* success */
> > +}
> > +
> > +/*
> > + * sxps2_close() frees the interrupt.
> > + */
> > +static void sxps2_close(struct serio *pserio)
> > +{
> > + struct xps2data *drvdata = pserio->port_data;
> > +
> > + /* Disable the PS2 interrupts */
> > + out_be32(drvdata->base_address + XPS2_GIER_OFFSET, 0x00);
> > + out_be32(drvdata->base_address + XPS2_IPIER_OFFSET, 0x00);
> > + free_irq(drvdata->irq, drvdata);
> > +}
> > +
> > +/*********************/
> > +/* Device setup code */
> > +/*********************/
> > +
> > +static int xps2_setup(struct device *dev, struct resource
*regs_res,
> > + struct resource *irq_res)
> > +{
>
> Why not just merge this with the of_ code now that you only have a
> single user of it?
>
> > + struct xps2data *drvdata;
> > + struct serio *serio;
> > + unsigned long remap_size;
> > + int retval;
> > +
> > + if (!dev)
> > + return -EINVAL;
> > +
> > + drvdata = kzalloc(sizeof(struct xps2data), GFP_KERNEL);
> > + if (!drvdata) {
> > + dev_err(dev, "Couldn't allocate device private
record\n");
> > + return -ENOMEM;
> > + }
> > + spin_lock_init(&drvdata->lock);
> > + dev_set_drvdata(dev, drvdata);
> > +
> > + if (!regs_res || !irq_res) {
> > + dev_err(dev, "IO resource(s) not found\n");
> > + retval = -EFAULT;
> > + goto failed1;
> > + }
> > +
> > + drvdata->irq = irq_res->start;
> > + remap_size = regs_res->end - regs_res->start + 1;
> > + if (!request_mem_region(regs_res->start, remap_size,
DRIVER_NAME)) {
> > +
> > + dev_err(dev, "Couldn't lock memory region at 0x%08X\n",
> > + (unsigned int)regs_res->start);
> > + retval = -EBUSY;
> > + goto failed1;
> > + }
> > +
> > + /* Fill in configuration data and add them to the list */
> > + drvdata->phys_addr = regs_res->start;
> > + drvdata->remap_size = remap_size;
> > + drvdata->base_address = ioremap(regs_res->start, remap_size);
> > + if (drvdata->base_address == NULL) {
> > +
> > + dev_err(dev, "Couldn't ioremap memory at 0x%08X\n",
> > + (unsigned int)regs_res->start);
> > + retval = -EFAULT;
> > + goto failed2;
> > + }
> > +
> > + /* Disable all the interrupts, just in case */
> > + out_be32(drvdata->base_address + XPS2_IPIER_OFFSET, 0);
> > +
> > + /* Reset the PS2 device and abort any current transaction, to
make sure
> > + * we have the PS2 in a good state */
> > + out_be32(drvdata->base_address + XPS2_SRST_OFFSET,
XPS2_SRST_RESET);
> > +
> > + dev_info(dev, "Xilinx PS2 at 0x%08X mapped to 0x%08X, irq=%d\n",
> > + drvdata->phys_addr, (u32)drvdata->base_address,
drvdata->irq);
> > +
> > + serio = &drvdata->serio;
> > + serio->id.type = SERIO_8042;
> > + serio->write = sxps2_write;
> > + serio->open = sxps2_open;
> > + serio->close = sxps2_close;
> > + serio->port_data = drvdata;
> > + serio->dev.parent = dev;
> > + snprintf(drvdata->serio.name, sizeof(serio->name),
> > + "Xilinx XPS PS/2 at %08X", drvdata->phys_addr);
> > + snprintf(drvdata->serio.phys, sizeof(serio->phys),
> > + "xilinxps2/serio at %08X", drvdata->phys_addr);
> > + serio_register_port(serio);
> > +
> > + return 0; /* success */
> > +
> > +failed2:
> > + release_mem_region(regs_res->start, remap_size);
> > +
> > +failed1:
> > + kfree(drvdata);
> > + dev_set_drvdata(dev, NULL);
> > +
> > + return retval;
> > +}
> > +
> > +/***************************/
> > +/* OF Platform Bus Support */
> > +/***************************/
> > +
> > +static int __devinit xps2_of_probe(struct of_device *ofdev, const
struct
> > + of_device_id * match)
> > +{
> > + struct resource r_irq; /* Interrupt resources */
> > + struct resource r_mem; /* IO mem resources */
> > + int rc = 0;
> > +
> > + printk(KERN_INFO "Device Tree Probing \'%s\'\n",
> > + ofdev->node->name);
> > +
> > + /* Get iospace for the device */
> > + rc = of_address_to_resource(ofdev->node, 0, &r_mem);
> > + if (rc) {
> > + dev_err(&ofdev->dev, "invalid address\n");
> > + return rc;
> > + }
> > +
> > + /* Get IRQ for the device */
> > + rc = of_irq_to_resource(ofdev->node, 0, &r_irq);
> > + if (rc == NO_IRQ) {
> > + dev_err(&ofdev->dev, "no IRQ found\n");
> > + return rc;
> > + }
> > +
> > + return xps2_setup(&ofdev->dev, &r_mem, &r_irq);
> > +}
> > +
> > +static int __devexit xps2_of_remove(struct of_device *of_dev)
> > +{
> > + struct xps2data *drvdata;
> > + struct device *dev;
> > +
> > + dev = &of_dev->dev;
> > + if (!dev)
> > + return -EINVAL;
> > +
> > + drvdata = (struct xps2data *)dev_get_drvdata(dev);
> > +
> > + serio_unregister_port(&drvdata->serio);
> > +
> > + iounmap(drvdata->base_address);
> > +
> > + release_mem_region(drvdata->phys_addr, drvdata->remap_size);
> > +
> > + kfree(drvdata);
> > + dev_set_drvdata(dev, NULL);
> > +
> > + return 0; /* success */
> > +}
> > +
> > +/* Match table for of_platform binding */
> > +static struct of_device_id xps2_of_match[] __devinitdata = {
> > + { .compatible = "xlnx,xps-ps2-1.00.a", },
> > + { /* end of list */ },
> > +};
> > +MODULE_DEVICE_TABLE(of, xps2_of_match);
> > +
> > +static struct of_platform_driver xps2_of_driver = {
> > + .name = DRIVER_NAME,
> > + .match_table = xps2_of_match,
> > + .probe = xps2_of_probe,
> > + .remove = __devexit_p(xps2_of_remove),
> > +};
> > +
> > +static int __init xps2_init(void)
> > +{
> > + return of_register_platform_driver(&xps2_of_driver);
> > +}
> > +
> > +static void __exit xps2_cleanup(void)
> > +{
> > + of_unregister_platform_driver(&xps2_of_driver);
> > +}
> > +
> > +module_init(xps2_init);
> > +module_exit(xps2_cleanup);
> > +
> > +MODULE_AUTHOR("Xilinx, Inc.");
> > +MODULE_DESCRIPTION("Xilinx XPS PS/2 driver");
> > +MODULE_LICENSE("GPL");
> > +
> > --
> > 1.5.2.1
>
> --
> Bye, Peter Korsgaard
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