RE: [PATCH v2 1/2] PRUSS UIO driver support

From: TK, Pratheesh Gangadhar
Date: Tue Feb 22 2011 - 07:01:53 EST


Hi,

> -----Original Message-----
> From: Hans J. Koch [mailto:hjk@xxxxxxxxxxxx]
> Sent: Tuesday, February 22, 2011 12:15 AM
> To: TK, Pratheesh Gangadhar
> Cc: davinci-linux-open-source@xxxxxxxxxxxxxxxxxxxx; hjk@xxxxxxxxxxxx;
> gregkh@xxxxxxx; Chatterjee, Amit; linux-kernel@xxxxxxxxxxxxxxx; linux-arm-
> kernel@xxxxxxxxxxxxxxxxxxx
> Subject: Re: [PATCH v2 1/2] PRUSS UIO driver support
>
> On Mon, Feb 21, 2011 at 11:05:14PM +0530, Pratheesh Gangadhar wrote:
> > This patch implements PRUSS (Programmable Real-time Unit Sub System)
> > UIO driver which exports SOC resources associated with PRUSS like
> > I/O, memories and IRQs to user space. PRUSS is dual 32-bit RISC
> > processors which is efficient in performing embedded tasks that
> > require manipulation of packed memory mapped data structures and
> > efficient in handling system events that have tight real time
> > constraints. This driver is currently supported on Texas Instruments
> > DA850, AM18xx and OMAPL1-38 devices.
> > For example, PRUSS runs firmware for real-time critical industrial
> > communication data link layer and communicates with application stack
> > running in user space via shared memory and IRQs.
> >
> > Signed-off-by: Pratheesh Gangadhar <pratheesh@xxxxxx>
>
> Looks much better now. Just some minor issues, see below.
>
> Thanks,
> Hans
>
> > ---
> > drivers/uio/Kconfig | 9 ++
> > drivers/uio/Makefile | 1 +
> > drivers/uio/uio_pruss.c | 231
> +++++++++++++++++++++++++++++++++++++++++++++++
> > 3 files changed, 241 insertions(+), 0 deletions(-)
> > create mode 100644 drivers/uio/uio_pruss.c
> >
> > diff --git a/drivers/uio/Kconfig b/drivers/uio/Kconfig
> > index bb44079..f92f20d 100644
> > --- a/drivers/uio/Kconfig
> > +++ b/drivers/uio/Kconfig
> > @@ -94,4 +94,13 @@ config UIO_NETX
> > To compile this driver as a module, choose M here; the module
> > will be called uio_netx.
> >
> > +config UIO_PRUSS
> > + tristate "Texas Instruments PRUSS driver"
> > + depends on ARCH_DAVINCI_DA850
> > + help
> > + PRUSS driver for OMAPL138/DA850/AM18XX devices
> > + PRUSS driver requires user space components
>
> It would be nice to mention a link here where these user space components
> are
> available.
Ok, will do.
>
> > + To compile this driver as a module, choose M here: the module
> > + will be called uio_pruss.
> > +
> > endif
> > diff --git a/drivers/uio/Makefile b/drivers/uio/Makefile
> > index 18fd818..d4dd9a5 100644
> > --- a/drivers/uio/Makefile
> > +++ b/drivers/uio/Makefile
> > @@ -6,3 +6,4 @@ obj-$(CONFIG_UIO_AEC) += uio_aec.o
> > obj-$(CONFIG_UIO_SERCOS3) += uio_sercos3.o
> > obj-$(CONFIG_UIO_PCI_GENERIC) += uio_pci_generic.o
> > obj-$(CONFIG_UIO_NETX) += uio_netx.o
> > +obj-$(CONFIG_UIO_PRUSS) += uio_pruss.o
> > diff --git a/drivers/uio/uio_pruss.c b/drivers/uio/uio_pruss.c
> > new file mode 100644
> > index 0000000..b402197
> > --- /dev/null
> > +++ b/drivers/uio/uio_pruss.c
> > @@ -0,0 +1,231 @@
> > +/*
> > + * Programmable Real-Time Unit Sub System (PRUSS) UIO driver
> (uio_pruss)
> > + *
> > + * This driver exports PRUSS host event out interrupts and PRUSS, L3
> RAM,
> > + * and DDR RAM to user space for applications interacting with PRUSS
> firmware
> > + *
> > + * Copyright (C) 2010-11 Texas Instruments Incorporated -
> http://www.ti.com/
> > + *
> > + * 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 version 2.
> > + *
> > + * This program is distributed "as is" WITHOUT ANY WARRANTY of any
> > + * kind, whether express or implied; without even the implied warranty
> > + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> > + * GNU General Public License for more details.
> > + */
> > +#include <linux/device.h>
> > +#include <linux/module.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/uio_driver.h>
> > +#include <linux/io.h>
> > +#include <linux/clk.h>
> > +#include <linux/dma-mapping.h>
> > +#include <linux/slab.h>
> > +
> > +#define DRV_NAME "pruss"
> > +#define DRV_VERSION "0.50"
> > +
> > +/*
> > + * Host event IRQ numbers from PRUSS - PRUSS can generate upto 8
> interrupt
> > + * events to AINTC of ARM host processor - which can be used for IPC
> b/w PRUSS
> > + * firmware and user space application, async notification from PRU
> firmware
> > + * to user space application
> > + * 3 PRU_EVTOUT0
> > + * 4 PRU_EVTOUT1
> > + * 5 PRU_EVTOUT2
> > + * 6 PRU_EVTOUT3
> > + * 7 PRU_EVTOUT4
> > + * 8 PRU_EVTOUT5
> > + * 9 PRU_EVTOUT6
> > + * 10 PRU_EVTOUT7
> > +*/
> > +
> > +#define MAX_PRUSS_EVTOUT_INSTANCE 8
> > +
> > +#define PRUSS_INTC_HIPIR 0x4900
> > +#define PRUSS_INTC_HIPIR_INTPEND_MASK 0x80000000
> > +#define PRUSS_INTC_HIER 0x5500
> > +
> > +struct clk *pruss_clk;
> > +struct uio_info *info;
> > +void *ddr_virt_addr;
> > +dma_addr_t ddr_phy_addr;
> > +
> > +static irqreturn_t pruss_handler(int irq, struct uio_info *dev_info)
> > +{
> > + void __iomem *int_enable_reg = dev_info->mem[0].internal_addr
> > + + PRUSS_INTC_HIER;
> > + void __iomem *int_status_reg = dev_info->mem[0].internal_addr
> > + + PRUSS_INTC_HIPIR+((irq-1) << 2);
>
> Blank line between variable definitions and code, please.
>
Ok.
> > + /* Is interrupt enabled and active ? */
> > + if (!(ioread32(int_enable_reg) & (1<<(irq-1))) &&
>
> Hmm. I'd prefer blanks around operands, like (1 << (irq - 1))).
> I won't be too picky about that, noticing that checkpatch.pl doesn't
> complain.
> If you want to do me a favor, you can fix it ;-)
>
Ok.
> > + (ioread32(int_status_reg) & PRUSS_INTC_HIPIR_INTPEND_MASK))
> > + return IRQ_NONE;
> > +
> > + /* Disable interrupt */
> > + iowrite32(ioread32(int_enable_reg) & ~(1<<(irq-1)),
>
> If you save the return value of the first ioread32(int_enable_reg) in a
> variable,
> you don't need the second hardware access.
>
Will do.
> > + int_enable_reg);
> > + return IRQ_HANDLED;
> > +}
> > +
> > +static void pruss_cleanup(struct platform_device *dev, struct uio_info
> *info)
> > +{
> > + int count;
>
> Blank line between variable definitions and code, please.
>
Ok.
> > + if (info) {
> > + for (count = 0; count < MAX_PRUSS_EVTOUT_INSTANCE; count++) {
> > + uio_unregister_device(&info[count]);
> > + kfree(info[count].name);
> > + iounmap(info[count].mem[0].internal_addr);
> > +
> > + }
> > + if (ddr_virt_addr)
> > + dma_free_coherent(&dev->dev, info[0].mem[2].size,
> > + info[0].mem[2].internal_addr,
> > + info[0].mem[2].addr);
> > + kfree(info);
> > + }
> > + if (pruss_clk != NULL)
> > + clk_put(pruss_clk);
> > +}
> > +
> > +static int __devinit pruss_probe(struct platform_device *dev)
> > +{
> > + int ret = -ENODEV, count = 0;
> > + struct resource *regs_pruram, *regs_l3ram, *regs_ddr;
> > + char *string;
> > +
> > + /* Power on PRU in case its not done as part of boot-loader */
> > + pruss_clk = clk_get(&dev->dev, "pruss");
> > + if (IS_ERR(pruss_clk)) {
> > + dev_err(&dev->dev, "Failed to get clock\n");
> > + ret = PTR_ERR(pruss_clk);
> > + return ret;
> > + } else {
> > + clk_enable(pruss_clk);
> > + }
> > +
> > + info = kzalloc(sizeof(struct uio_info) * MAX_PRUSS_EVTOUT_INSTANCE,
> > + GFP_KERNEL);
> > + if (info == NULL)
>
> if (!info) looks better.
>
> > + return -ENOMEM;
> > +
> > + regs_pruram = platform_get_resource(dev, IORESOURCE_MEM, 0);
> > + if (!regs_pruram) {
> > + dev_err(&dev->dev, "No memory resource specified\n");
> > + goto out_free;
> > + }
> > +
> > + regs_l3ram = platform_get_resource(dev, IORESOURCE_MEM, 1);
> > + if (!regs_l3ram) {
> > + dev_err(&dev->dev, "No memory resource specified\n");
> > + goto out_free;
> > + }
> > +
> > + regs_ddr = platform_get_resource(dev, IORESOURCE_MEM, 2);
> > + if (!regs_ddr) {
> > + dev_err(&dev->dev, "No memory resource specified\n");
> > + goto out_free;
> > + }
> > + ddr_virt_addr =
> > + dma_alloc_coherent(&dev->dev, regs_ddr->end - regs_ddr->start +
> 1,
> > + &ddr_phy_addr, GFP_KERNEL | GFP_DMA);
> > + if (!ddr_virt_addr) {
> > + dev_err(&dev->dev, "Could not allocate external memory\n");
> > + goto out_free;
> > + }
> > +
> > + for (count = 0; count < MAX_PRUSS_EVTOUT_INSTANCE; count++) {
> > + info[count].mem[0].addr = regs_pruram->start;
> > + info[count].mem[0].size =
> > + regs_pruram->end - regs_pruram->start + 1;
> > + if (!info[count].mem[0].addr ||
> > + !(info[count].mem[0].size - 1)) {
> > + dev_err(&dev->dev, "Invalid memory resource\n");
> > + goto out_free;
> > + }
> > + info[count].mem[0].internal_addr =
> > + ioremap(regs_pruram->start, info[count].mem[0].size);
> > + if (!info[count].mem[0].internal_addr) {
> > + dev_err(&dev->dev,
> > + "Can't remap memory address range\n");
> > + goto out_free;
> > + }
> > + info[count].mem[0].memtype = UIO_MEM_PHYS;
> > +
> > + info[count].mem[1].addr = regs_l3ram->start;
> > + info[count].mem[1].size =
> > + regs_l3ram->end - regs_l3ram->start + 1;
> > + if (!info[count].mem[1].addr ||
> > + !(info[count].mem[1].size - 1)) {
> > + dev_err(&dev->dev, "Invalid memory resource\n");
> > + goto out_free;
> > + }
> > + info[count].mem[1].memtype = UIO_MEM_PHYS;
> > +
> > + info[count].mem[2].internal_addr = ddr_virt_addr;
> > + info[count].mem[2].addr = ddr_phy_addr;
> > + info[count].mem[2].size = regs_ddr->end - regs_ddr->start + 1;
> > + info[count].mem[2].memtype = UIO_MEM_PHYS;
> > +
> > + string = kzalloc(20, GFP_KERNEL);
> > + sprintf(string, "pruss_evt%d", count);
> > + info[count].name = string;
> > + info[count].version = "0.50";
> > +
> > + /* Register PRUSS IRQ lines */
> > + info[count].irq = IRQ_DA8XX_EVTOUT0 + count;
> > +
> > + info[count].irq_flags = 0;
> > + info[count].handler = pruss_handler;
> > +
> > + ret = uio_register_device(&dev->dev, &info[count]);
> > +
> > + if (ret < 0)
> > + goto out_free;
> > + }
> > +
> > + platform_set_drvdata(dev, info);
> > + return 0;
> > +
> > +out_free:
> > + pruss_cleanup(dev, info);
> > + return ret;
> > +}
> > +
> > +static int __devexit pruss_remove(struct platform_device *dev)
> > +{
> > + struct uio_info *info = platform_get_drvdata(dev);
>
> Blank line, please.
>
Ok.

Thanks,
Pratheesh
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