[PATCH v9 0/1] Add PRUSS UIO driver support

[PATCH v9 0/1] Add PRUSS UIO driver support

[Pratheesh Gangadhar]

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   |  264 +++++++++++++++++++++++++++++++++++++++++++++
 include/linux/uio_pruss.h |   29 +++++
 4 files changed, 311 insertions(+), 0 deletions(-)
 create mode 100644 drivers/uio/uio_pruss.c
 create mode 100644 include/linux/uio_pruss.h

[PATCH v9 1/1] PRUSS UIO driver support

[Pratheesh Gangadhar]

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 <pratheesh@ti.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
---
 drivers/uio/Kconfig       |   17 +++
 drivers/uio/Makefile      |    1 +
 drivers/uio/uio_pruss.c   |  264 +++++++++++++++++++++++++++++++++++++++++++++
 include/linux/uio_pruss.h |   29 +++++
 4 files changed, 311 insertions(+), 0 deletions(-)
 create mode 100644 drivers/uio/uio_pruss.c
 create mode 100644 include/linux/uio_pruss.h

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..519e53d
--- /dev/null
+++ b/drivers/uio/uio_pruss.c
@@ -0,0 +1,264 @@
+/*
+ * 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/uio_pruss.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	0x0038
+#define PINTC_HIPIR	0x0900
+#define HIPIR_NOPEND	0x80000000
+#define PINTC_HIER	0x1500
+
+struct uio_pruss_dev {
+	struct uio_info *info;
+	struct clk *pruss_clk;
+	dma_addr_t sram_paddr;
+	dma_addr_t ddr_paddr;
+	void __iomem *prussio_vaddr;
+	void *sram_vaddr;
+	void *ddr_vaddr;
+	unsigned int hostirq_start;
+	unsigned int pintc_base;
+};
+
+struct pruss_priv {
+	struct uio_pruss_dev *pupdev;
+};
+
+static irqreturn_t pruss_handler(int irq, struct uio_info *info)
+{
+	struct pruss_priv *priv = info->priv;
+	struct uio_pruss_dev *gdev = priv->pupdev;
+	int intr_bit = (irq - gdev->hostirq_start + 2);
+	int val, intr_mask = (1 << intr_bit);
+	void __iomem *base = info->mem[0].internal_addr + gdev->pintc_base;
+	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_pruss_dev *gdev)
+{
+	int cnt;
+	struct uio_info *p = gdev->info;
+
+	for (cnt = 0; cnt < MAX_PRUSS_EVT; cnt++, p++) {
+		uio_unregister_device(p);
+		kfree(p->name);
+	}
+	iounmap(gdev->prussio_vaddr);
+	if (gdev->ddr_vaddr) {
+		dma_free_coherent(&dev->dev, extram_pool_sz, gdev->ddr_vaddr,
+			gdev->ddr_paddr);
+	}
+	if (gdev->sram_vaddr)
+		sram_free(gdev->sram_vaddr, sram_pool_sz);
+	kfree(gdev->info->priv);
+	kfree(gdev->info);
+	clk_put(gdev->pruss_clk);
+	kfree(gdev);
+}
+
+static int __devinit pruss_probe(struct platform_device *dev)
+{
+	struct uio_info *p;
+	struct pruss_priv *priv;
+	struct uio_pruss_dev *gdev;
+	struct resource *regs_prussio;
+	int ret = -ENODEV, cnt = 0, len;
+	struct uio_pruss_pdata *pdata = dev->dev.platform_data;
+
+	gdev = kzalloc(sizeof(struct uio_pruss_dev), GFP_KERNEL);
+	if (!gdev)
+		return -ENOMEM;
+	priv = kzalloc(sizeof(struct pruss_priv), GFP_KERNEL);
+	if (!priv) {
+		kfree(gdev);
+		return -ENOMEM;
+	}
+
+	priv->pupdev = gdev;
+
+	gdev->info = kzalloc(sizeof(*p) * MAX_PRUSS_EVT, GFP_KERNEL);
+	if (!gdev->info) {
+		kfree(priv);
+		kfree(gdev);
+		return -ENOMEM;
+	}
+	/* Power on PRU in case its not done as part of boot-loader */
+	gdev->pruss_clk = clk_get(&dev->dev, "pruss");
+	if (IS_ERR(gdev->pruss_clk)) {
+		dev_err(&dev->dev, "Failed to get clock\n");
+		kfree(gdev->info);
+		kfree(priv);
+		kfree(gdev);
+		ret = PTR_ERR(gdev->pruss_clk);
+		return ret;
+	} else {
+		clk_enable(gdev->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;
+	}
+
+	gdev->sram_vaddr = sram_alloc(sram_pool_sz, &(gdev->sram_paddr));
+	if (!gdev->sram_vaddr) {
+		dev_err(&dev->dev, "Could not allocate SRAM pool\n");
+		goto out_free;
+	}
+
+	gdev->ddr_vaddr = dma_alloc_coherent(&dev->dev, extram_pool_sz,
+				&(gdev->ddr_paddr), GFP_KERNEL | GFP_DMA);
+	if (!gdev->ddr_vaddr) {
+		dev_err(&dev->dev, "Could not allocate external memory\n");
+		goto out_free;
+	}
+
+	len = resource_size(regs_prussio);
+	gdev->prussio_vaddr = ioremap(regs_prussio->start, len);
+	if (!gdev->prussio_vaddr) {
+		dev_err(&dev->dev, "Can't remap PRUSS I/O  address range\n");
+		goto out_free;
+	}
+
+	gdev->pintc_base = pdata->pintc_base;
+	gdev->hostirq_start = platform_get_irq(dev, 0);
+
+	for (cnt = 0, p = gdev->info; cnt < MAX_PRUSS_EVT; cnt++, p++) {
+		p->mem[0].internal_addr = gdev->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].addr = gdev->sram_paddr;
+		p->mem[1].size = sram_pool_sz;
+		p->mem[1].memtype = UIO_MEM_PHYS;
+
+		p->mem[2].addr = gdev->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 = DRV_VERSION;
+
+		/* Register PRUSS IRQ lines */
+		p->irq = gdev->hostirq_start + cnt;
+		p->handler = pruss_handler;
+		p->priv = priv;
+
+		ret = uio_register_device(&dev->dev, p);
+		if (ret < 0)
+			goto out_free;
+	}
+
+	platform_set_drvdata(dev, gdev);
+	return 0;
+
+out_free:
+	pruss_cleanup(dev, gdev);
+	return ret;
+}
+
+static int __devexit pruss_remove(struct platform_device *dev)
+{
+	struct uio_pruss_dev *gdev = platform_get_drvdata(dev);
+
+	pruss_cleanup(dev, gdev);
+	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 <amit.chatterjee@ti.com>");
+MODULE_AUTHOR("Pratheesh Gangadhar <pratheesh@ti.com>");
diff --git a/include/linux/uio_pruss.h b/include/linux/uio_pruss.h
new file mode 100644
index 0000000..2164845
--- /dev/null
+++ b/include/linux/uio_pruss.h
@@ -0,0 +1,29 @@
+/*
+ * include/linux/uio_pruss.h
+ *
+ * Platform data for uio_pruss driver
+ *
+ * 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.
+ */
+
+#ifndef _UIO_PRUSS_H_
+#define _UIO_PRUSS_H_
+
+/* Used to configure the PRUSS INTC base offset for UIO driver */
+struct uio_pruss_pdata {
+	u32	pintc_base;
+};
+
+#endif /* _LINUX_UIO_PRUSS_H_ */
+
+
+
-- 
1.6.0.6

Re: [PATCH v9 1/1] PRUSS UIO driver support

[Arnd Bergmann]

On Thursday 03 March 2011 19:07:57 Pratheesh Gangadhar wrote:
> +struct uio_pruss_dev {
> +       struct uio_info *info;
> +       struct clk *pruss_clk;
> +       dma_addr_t sram_paddr;
> +       dma_addr_t ddr_paddr;
> +       void __iomem *prussio_vaddr;
> +       void *sram_vaddr;
> +       void *ddr_vaddr;
> +       unsigned int hostirq_start;
> +       unsigned int pintc_base;
> +};
> +
> +struct pruss_priv {
> +       struct uio_pruss_dev *pupdev;
> +};

I cannot see the point of struct pruss_priv, I think it would be better to
just merge the two data structures into one. Everything else looks
good to me now.

	Arnd

RE: [PATCH v9 1/1] PRUSS UIO driver support

[TK, Pratheesh Gangadhar]

Hi,
> -----Original Message-----
> From: Arnd Bergmann [mailto:arnd@arndb.de]
> Sent: Thursday, March 03, 2011 11:46 PM
> On Thursday 03 March 2011 19:07:57 Pratheesh Gangadhar wrote:
> > +struct uio_pruss_dev {
> > +       struct uio_info *info;
> > +       struct clk *pruss_clk;
> > +       dma_addr_t sram_paddr;
> > +       dma_addr_t ddr_paddr;
> > +       void __iomem *prussio_vaddr;
> > +       void *sram_vaddr;
> > +       void *ddr_vaddr;
> > +       unsigned int hostirq_start;
> > +       unsigned int pintc_base;
> > +};
> > +
> > +struct pruss_priv {
> > +       struct uio_pruss_dev *pupdev;
> > +};
> 
> I cannot see the point of struct pruss_priv, I think it would be better to
> just merge the two data structures into one. Everything else looks
> good to me now.

pruss_priv is needed to get access to uio_pruss_dev from uio_info *info in
UIO interrupt handler (pruss_handler) and shall be per interrupt entry.

+static irqreturn_t pruss_handler(int irq, struct uio_info *info) {
+	struct pruss_priv *priv = info->priv;
+	struct uio_pruss_dev *gdev = priv->pupdev;

Note that info is a pointer to array supporting 8 interrupts. This allows to
redirect to driver structure via info->priv quickly.

Thanks,
Pratheesh   

RE: [PATCH v9 1/1] PRUSS UIO driver support

[Thomas Gleixner]

On Fri, 4 Mar 2011, TK, Pratheesh Gangadhar wrote:

> Hi,
> > -----Original Message-----
> > From: Arnd Bergmann [mailto:arnd@arndb.de]
> > Sent: Thursday, March 03, 2011 11:46 PM
> > On Thursday 03 March 2011 19:07:57 Pratheesh Gangadhar wrote:
> > > +struct uio_pruss_dev {
> > > +       struct uio_info *info;
> > > +       struct clk *pruss_clk;
> > > +       dma_addr_t sram_paddr;
> > > +       dma_addr_t ddr_paddr;
> > > +       void __iomem *prussio_vaddr;
> > > +       void *sram_vaddr;
> > > +       void *ddr_vaddr;
> > > +       unsigned int hostirq_start;
> > > +       unsigned int pintc_base;
> > > +};
> > > +
> > > +struct pruss_priv {
> > > +       struct uio_pruss_dev *pupdev;
> > > +};
> > 
> > I cannot see the point of struct pruss_priv, I think it would be better to
> > just merge the two data structures into one. Everything else looks
> > good to me now.
> 
> pruss_priv is needed to get access to uio_pruss_dev from uio_info *info in
> UIO interrupt handler (pruss_handler) and shall be per interrupt entry.
> 
> +static irqreturn_t pruss_handler(int irq, struct uio_info *info) {
> +	struct pruss_priv *priv = info->priv;
> +	struct uio_pruss_dev *gdev = priv->pupdev;
> 
> Note that info is a pointer to array supporting 8 interrupts. This allows to
> redirect to driver structure via info->priv quickly.

struct uio_pruss_dev *dev = container_of(info, struct uio_pruss_dev, info);

Perhaps ?

Thanks,

	tglx

Re: [PATCH v9 1/1] PRUSS UIO driver support

[Arnd Bergmann]

On Tuesday 08 March 2011, Thomas Gleixner wrote:
> > 
> > +static irqreturn_t pruss_handler(int irq, struct uio_info *info) {
> > +     struct pruss_priv *priv = info->priv;
> > +     struct uio_pruss_dev *gdev = priv->pupdev;
> > 
> > Note that info is a pointer to array supporting 8 interrupts. This allows to
> > redirect to driver structure via info->priv quickly.
> 
> struct uio_pruss_dev *dev = container_of(info, struct uio_pruss_dev, info);
> 
> Perhaps ?

That would require having the same number of uio_info structs as uio_pruss_dev
instances. Right now, one platform device has one uio_pruss_dev instance, which
has 8 uio_info instances, so the container_of() trick doesn't work.

	Arnd

Re: [PATCH v9 1/1] PRUSS UIO driver support

[Thomas Gleixner]

On Tue, 8 Mar 2011, Arnd Bergmann wrote:

> On Tuesday 08 March 2011, Thomas Gleixner wrote:
> > > 
> > > +static irqreturn_t pruss_handler(int irq, struct uio_info *info) {
> > > +     struct pruss_priv *priv = info->priv;
> > > +     struct uio_pruss_dev *gdev = priv->pupdev;
> > > 
> > > Note that info is a pointer to array supporting 8 interrupts. This allows to
> > > redirect to driver structure via info->priv quickly.
> > 
> > struct uio_pruss_dev *dev = container_of(info, struct uio_pruss_dev, info);
> > 
> > Perhaps ?
> 
> That would require having the same number of uio_info structs as uio_pruss_dev
> instances. Right now, one platform device has one uio_pruss_dev instance, which
> has 8 uio_info instances, so the container_of() trick doesn't work.

Duh. Yes :)

     tglx

RE: [PATCH v9 1/1] PRUSS UIO driver support

[TK, Pratheesh Gangadhar]

Hi,

> -----Original Message-----
> From: TK, Pratheesh Gangadhar
> Sent: Friday, March 04, 2011 8:55 AM
> > > +struct uio_pruss_dev {
> > > +       struct uio_info *info;
> > > +       struct clk *pruss_clk;
> > > +       dma_addr_t sram_paddr;
> > > +       dma_addr_t ddr_paddr;
> > > +       void __iomem *prussio_vaddr;
> > > +       void *sram_vaddr;
> > > +       void *ddr_vaddr;
> > > +       unsigned int hostirq_start;
> > > +       unsigned int pintc_base;
> > > +};
> > > +
> > > +struct pruss_priv {
> > > +       struct uio_pruss_dev *pupdev;
> > > +};
> >
> > I cannot see the point of struct pruss_priv, I think it would be better
> to
> > just merge the two data structures into one. Everything else looks
> > good to me now.
> 
> pruss_priv is needed to get access to uio_pruss_dev from uio_info *info in
> UIO interrupt handler (pruss_handler) and shall be per interrupt entry.
> 
> +static irqreturn_t pruss_handler(int irq, struct uio_info *info) {
> +	struct pruss_priv *priv = info->priv;
> +	struct uio_pruss_dev *gdev = priv->pupdev;
> 
> Note that info is a pointer to array supporting 8 interrupts. This allows
> to
> redirect to driver structure via info->priv quickly.
> 

I get your point, no need of additional structure here, can directly assign 
uio_pruss_dev pointer to info->priv. Will resubmit with this change.

Thanks,
Pratheesh