2011-03-02 11:38:40

by TK, Pratheesh Gangadhar

[permalink] [raw]
Subject: [PATCH v8 0/1] Add PRUSS UIO driver support

This patch series add support for PRUSS (Programmable Real-time Unit Sub
System) UIO driver in Texas Instruments DA850, AM18xx and OMAP-L138 processors.
PRUSS is programmable RISC core which can be used to implement Soft IPs
(eg:- DMA, CAN, UART,SmartCard) and Industrial communications data link layers
(eg:- PROFIBUS). UIO driver exposes PRUSS resources like memory and interrupts
to user space application.PRUSS UIO application API can be used to control PRUs
in PRUSS, setup PRU INTC, load firmware to PRUs and implement IPC between Host
processor and PRUs. More information on PRUSS and UIO linux user space API
available in the links below

http://processors.wiki.ti.com/index.php/Programmable_Realtime_Unit_Subsystem
http://processors.wiki.ti.com/index.php/PRU_Linux_Application_Loader
http://processors.wiki.ti.com/index.php/PRU_Linux_Application_Loader_API_Guide

Platform/board specific portion of this patch depends on Mistral patches below

[PATCH 1/1] davinci: changed SRAM allocator to shared ram :
https://patchwork.kernel.org/patch/549351/
[PATCH 1/1] da830: macro rename DA8XX_LPSC0_DMAX to DA8XX_LPSC0_PRUSS :
https://patchwork.kernel.org/patch/549331/
[PATCH v2 01/13] mfd: pruss mfd driver :
https://patchwork.kernel.org/patch/549531/
[PATCH v2 02/13] da850: pruss platform specific additions :
https://patchwork.kernel.org/patch/549521/

I will submit a seperate patch set on top of these patches to support PRUSS
UIO driver.

Pratheesh Gangadhar (1):
PRUSS UIO driver support

drivers/uio/Kconfig | 17 ++++
drivers/uio/Makefile | 1 +
drivers/uio/uio_pruss.c | 226 +++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 244 insertions(+), 0 deletions(-)
create mode 100644 drivers/uio/uio_pruss.c


2011-03-02 11:38:43

by TK, Pratheesh Gangadhar

[permalink] [raw]
Subject: [PATCH v8 1/1] PRUSS UIO driver support

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
handling system events that have tight real time constraints. This
driver is currently supported on Texas Instruments DA850, AM18xx and
OMAP-L138 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 <[email protected]>
Reviewed-by: Thomas Gleixner <[email protected]>
---
drivers/uio/Kconfig | 17 ++++
drivers/uio/Makefile | 1 +
drivers/uio/uio_pruss.c | 226 +++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 244 insertions(+), 0 deletions(-)
create mode 100644 drivers/uio/uio_pruss.c

diff --git a/drivers/uio/Kconfig b/drivers/uio/Kconfig
index bb44079..6f3ea9b 100644
--- a/drivers/uio/Kconfig
+++ b/drivers/uio/Kconfig
@@ -94,4 +94,21 @@ 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, examples and user space
+ driver is available from below SVN repo - you may use anonymous login
+
+ https://gforge.ti.com/gf/project/pru_sw/
+
+ More info on API is available at below wiki
+
+ http://processors.wiki.ti.com/index.php/PRU_Linux_Application_Loader
+
+ 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..12469ae
--- /dev/null
+++ b/drivers/uio/uio_pruss.c
@@ -0,0 +1,226 @@
+/*
+ * 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/moduleparam.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>
+#include <mach/sram.h>
+
+#define DRV_NAME "pruss_uio"
+#define DRV_VERSION "0.50"
+
+static int sram_pool_sz = SZ_16K;
+module_param(sram_pool_sz, int, 0);
+MODULE_PARM_DESC(sram_pool_sz, "sram pool size to allocate ");
+
+static int extram_pool_sz = SZ_256K;
+module_param(extram_pool_sz, int, 0);
+MODULE_PARM_DESC(extram_pool_sz, "external ram pool size to allocate");
+
+/*
+ * 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_EVT 8
+
+#define PINTC_HIDISR 0x4038
+#define PINTC_HIPIR 0x4900
+#define HIPIR_NOPEND 0x80000000
+#define PINTC_HIER 0x5500
+
+static struct clk *pruss_clk;
+static struct uio_info *info;
+static dma_addr_t sram_paddr, ddr_paddr;
+static void *prussio_vaddr, *sram_vaddr, *ddr_vaddr;
+
+static irqreturn_t pruss_handler(int irq, struct uio_info *info)
+{
+ int intr_bit = (irq - IRQ_DA8XX_EVTOUT0 + 2);
+ int val, intr_mask = (1 << intr_bit);
+ void __iomem *base = info->mem[0].internal_addr;
+ void __iomem *intren_reg = base + PINTC_HIER;
+ void __iomem *intrdis_reg = base + PINTC_HIDISR;
+ void __iomem *intrstat_reg = base + PINTC_HIPIR + (intr_bit << 2);
+
+ val = ioread32(intren_reg);
+ /* Is interrupt enabled and active ? */
+ if (!(val & intr_mask) && (ioread32(intrstat_reg) & HIPIR_NOPEND))
+ return IRQ_NONE;
+ /* Disable interrupt */
+ iowrite32(intr_bit, intrdis_reg);
+ return IRQ_HANDLED;
+}
+
+static void pruss_cleanup(struct platform_device *dev, struct uio_info *info)
+{
+ int cnt;
+ struct uio_info *p = info;
+
+ for (cnt = 0; cnt < MAX_PRUSS_EVT; cnt++, p++) {
+ uio_unregister_device(p);
+ kfree(p->name);
+ }
+ iounmap(prussio_vaddr);
+ if (ddr_vaddr) {
+ dma_free_coherent(&dev->dev, extram_pool_sz, ddr_vaddr,
+ ddr_paddr);
+ }
+ if (sram_vaddr)
+ sram_free(sram_vaddr, sram_pool_sz);
+ kfree(info);
+ clk_put(pruss_clk);
+}
+
+static int __devinit pruss_probe(struct platform_device *dev)
+{
+ struct uio_info *p;
+ struct resource *regs_prussio;
+ int ret = -ENODEV, cnt = 0, len;
+
+ info = kzalloc(sizeof(struct uio_info) * MAX_PRUSS_EVT, GFP_KERNEL);
+ if (!info)
+ return -ENOMEM;
+ /* 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");
+ kfree(info);
+ ret = PTR_ERR(pruss_clk);
+ return ret;
+ } else {
+ clk_enable(pruss_clk);
+ }
+
+ regs_prussio = platform_get_resource(dev, IORESOURCE_MEM, 0);
+ if (!regs_prussio) {
+ dev_err(&dev->dev, "No PRUSS I/O resource specified\n");
+ goto out_free;
+ }
+
+ if (!regs_prussio->start) {
+ dev_err(&dev->dev, "Invalid memory resource\n");
+ goto out_free;
+ }
+
+ sram_vaddr = sram_alloc(sram_pool_sz, &sram_paddr);
+ if (!sram_vaddr) {
+ dev_err(&dev->dev, "Could not allocate SRAM pool\n");
+ goto out_free;
+ }
+
+ ddr_vaddr = dma_alloc_coherent(&dev->dev, extram_pool_sz, &ddr_paddr,
+ GFP_KERNEL | GFP_DMA);
+ if (!ddr_vaddr) {
+ dev_err(&dev->dev, "Could not allocate external memory\n");
+ goto out_free;
+ }
+
+ len = resource_size(regs_prussio);
+ prussio_vaddr = ioremap(regs_prussio->start, len);
+ if (!prussio_vaddr) {
+ dev_err(&dev->dev, "Can't remap PRUSS I/O address range\n");
+ goto out_free;
+ }
+
+ for (cnt = 0, p = info; cnt < MAX_PRUSS_EVT; cnt++, p++) {
+ p->mem[0].internal_addr = prussio_vaddr;
+ p->mem[0].addr = regs_prussio->start;
+ p->mem[0].size = resource_size(regs_prussio);
+ p->mem[0].memtype = UIO_MEM_PHYS;
+
+ p->mem[1].internal_addr = sram_vaddr;
+ p->mem[1].addr = sram_paddr;
+ p->mem[1].size = sram_pool_sz;
+ p->mem[1].memtype = UIO_MEM_PHYS;
+
+ p->mem[2].internal_addr = ddr_vaddr;
+ p->mem[2].addr = ddr_paddr;
+ p->mem[2].size = extram_pool_sz;
+ p->mem[2].memtype = UIO_MEM_PHYS;
+
+ p->name = kasprintf(GFP_KERNEL, "pruss_evt%d", cnt);
+ p->version = "0.50";
+
+ /* Register PRUSS IRQ lines */
+ p->irq = IRQ_DA8XX_EVTOUT0 + cnt;
+ p->handler = pruss_handler;
+
+ ret = uio_register_device(&dev->dev, p);
+ 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);
+
+ pruss_cleanup(dev, info);
+ platform_set_drvdata(dev, NULL);
+ return 0;
+}
+
+static struct platform_driver pruss_driver = {
+ .probe = pruss_probe,
+ .remove = __devexit_p(pruss_remove),
+ .driver = {
+ .name = DRV_NAME,
+ .owner = THIS_MODULE,
+ },
+};
+
+static int __init pruss_init_module(void)
+{
+ return platform_driver_register(&pruss_driver);
+}
+
+module_init(pruss_init_module);
+
+static void __exit pruss_exit_module(void)
+{
+ platform_driver_unregister(&pruss_driver);
+}
+
+module_exit(pruss_exit_module);
+
+MODULE_LICENSE("GPL v2");
+MODULE_VERSION(DRV_VERSION);
+MODULE_AUTHOR("Amit Chatterjee <[email protected]>");
+MODULE_AUTHOR("Pratheesh Gangadhar <[email protected]>");
--
1.6.0.6

2011-03-02 13:22:48

by Arnd Bergmann

[permalink] [raw]
Subject: Re: [PATCH v8 1/1] PRUSS UIO driver support

On Wednesday 02 March 2011, Pratheesh Gangadhar wrote:
> +
> +static struct clk *pruss_clk;
> +static struct uio_info *info;
> +static dma_addr_t sram_paddr, ddr_paddr;
> +static void *prussio_vaddr, *sram_vaddr, *ddr_vaddr;
> +

To my initial comment about these being single-instance
variables, you said you'd change that, which has not happened
yet.

Also, I now noticed that the types are wrong, you are
missing __iomem annotations for MMIO ranges. Please make
sure that the code builds fine with sparse and "make C=1",
which will tell you about these problems.

Arnd

2011-03-02 13:24:05

by Thomas Gleixner

[permalink] [raw]
Subject: Re: [PATCH v8 1/1] PRUSS UIO driver support

On Wed, 2 Mar 2011, 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
> handling system events that have tight real time constraints. This
> driver is currently supported on Texas Instruments DA850, AM18xx and
> OMAP-L138 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 <[email protected]>
> Reviewed-by: Thomas Gleixner <[email protected]>

No further objections.

Thanks for your patience,

tglx

2011-03-02 20:11:25

by Hans J. Koch

[permalink] [raw]
Subject: Re: [PATCH v8 1/1] PRUSS UIO driver support

On Wed, Mar 02, 2011 at 05:08:06PM +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
> handling system events that have tight real time constraints. This
> driver is currently supported on Texas Instruments DA850, AM18xx and
> OMAP-L138 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 <[email protected]>
> Reviewed-by: Thomas Gleixner <[email protected]>
> ---
> drivers/uio/Kconfig | 17 ++++
> drivers/uio/Makefile | 1 +
> drivers/uio/uio_pruss.c | 226 +++++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 244 insertions(+), 0 deletions(-)
> create mode 100644 drivers/uio/uio_pruss.c

That looks good now, I don't see any further issues. But you should
address Arnd's comment about that __iomem stuff. It's a bit nit-picking,
but he's right, ioremap() returns void __iomem *, and uio_mem.internal_addr
also has that type.

> +static struct uio_info *info;
> +static dma_addr_t sram_paddr, ddr_paddr;
> +static void *prussio_vaddr, *sram_vaddr, *ddr_vaddr;

So the correct thing would be

static void __iomem *prussio_vaddr;
static void *sram_vaddr, *ddr_vaddr;

Thanks,
Hans

2011-03-02 20:24:31

by Arnd Bergmann

[permalink] [raw]
Subject: Re: [PATCH v8 1/1] PRUSS UIO driver support

On Wednesday 02 March 2011 21:09:56 Hans J. Koch wrote:
> > +static struct uio_info *info;
> > +static dma_addr_t sram_paddr, ddr_paddr;
> > +static void *prussio_vaddr, *sram_vaddr, *ddr_vaddr;
>
> So the correct thing would be
>
> static void __iomem *prussio_vaddr;
> static void *sram_vaddr, *ddr_vaddr;

I also commented that it should not be a global variable at
all, but a dynamic data structure referenced from the device.

Not important, but Pratheesh said he'd change it. If it stays
a global variable, I'd at least expect an explanation why
the static variable is considered better in this case.

Arnd

2011-03-02 20:57:18

by Thomas Gleixner

[permalink] [raw]
Subject: Re: [PATCH v8 1/1] PRUSS UIO driver support

On Wed, 2 Mar 2011, Arnd Bergmann wrote:

> On Wednesday 02 March 2011 21:09:56 Hans J. Koch wrote:
> > > +static struct uio_info *info;
> > > +static dma_addr_t sram_paddr, ddr_paddr;
> > > +static void *prussio_vaddr, *sram_vaddr, *ddr_vaddr;
> >
> > So the correct thing would be
> >
> > static void __iomem *prussio_vaddr;
> > static void *sram_vaddr, *ddr_vaddr;
>
> I also commented that it should not be a global variable at
> all, but a dynamic data structure referenced from the device.
>
> Not important, but Pratheesh said he'd change it. If it stays
> a global variable, I'd at least expect an explanation why
> the static variable is considered better in this case.

I did not pick at that, because there is no indicator that we'll see
more than one PRUSS unit per SoC in the forseeable future.

Thanks,

tglx

2011-03-03 09:30:07

by TK, Pratheesh Gangadhar

[permalink] [raw]
Subject: RE: [PATCH v8 1/1] PRUSS UIO driver support


Hi,
> -----Original Message-----
> From: Thomas Gleixner [mailto:[email protected]]
> Sent: Thursday, March 03, 2011 2:27 AM
> On Wed, 2 Mar 2011, Arnd Bergmann wrote:
>
> > On Wednesday 02 March 2011 21:09:56 Hans J. Koch wrote:
> > > > +static struct uio_info *info;
> > > > +static dma_addr_t sram_paddr, ddr_paddr;
> > > > +static void *prussio_vaddr, *sram_vaddr, *ddr_vaddr;
> > >
> > > So the correct thing would be
> > >
> > > static void __iomem *prussio_vaddr;
> > > static void *sram_vaddr, *ddr_vaddr;
> >
> > I also commented that it should not be a global variable at
> > all, but a dynamic data structure referenced from the device.
> >
> > Not important, but Pratheesh said he'd change it. If it stays
> > a global variable, I'd at least expect an explanation why
> > the static variable is considered better in this case.
>
> I did not pick at that, because there is no indicator that we'll see
> more than one PRUSS unit per SoC in the forseeable future.
>
It's a possibility - May be in 2-3 years time.

Thanks,
Pratheesh

2011-03-03 09:34:21

by TK, Pratheesh Gangadhar

[permalink] [raw]
Subject: RE: [PATCH v8 1/1] PRUSS UIO driver support

Hi,

> -----Original Message-----
> From: Arnd Bergmann [mailto:[email protected]]
> Sent: Wednesday, March 02, 2011 6:52 PM
> On Wednesday 02 March 2011, Pratheesh Gangadhar wrote:
> > +
> > +static struct clk *pruss_clk;
> > +static struct uio_info *info;
> > +static dma_addr_t sram_paddr, ddr_paddr;
> > +static void *prussio_vaddr, *sram_vaddr, *ddr_vaddr;
> > +
>
> To my initial comment about these being single-instance
> variables, you said you'd change that, which has not happened
> yet.
>
I will do this in next version. Also realized that in next SoC,
PRU INTC base offset is different, so plan to add a platform_data
variable to make this portable.

+#define PINTC_HIDISR 0x4038
+#define PINTC_HIPIR 0x4900
+#define PINTC_HIER 0x5500

These hard coding also need to go to make it fully portable.
+int intr_bit = (irq - IRQ_DA8XX_EVTOUT0 + 2);
+p->irq = IRQ_DA8XX_EVTOUT0 + cnt;

> Also, I now noticed that the types are wrong, you are
> missing __iomem annotations for MMIO ranges. Please make
> sure that the code builds fine with sparse and "make C=1",
> which will tell you about these problems.
>
Thanks, this also helped to identify 2 unused lines in the code.

+ p->mem[1].internal_addr = sram_vaddr;
+ p->mem[2].internal_addr = ddr_vaddr;

Pratheesh