cregit-Linux how code gets into the kernel

Release 4.11 drivers/video/fbdev/pxa3xx-gcu.c

/*
 *  pxa3xx-gcu.c - Linux kernel module for PXA3xx graphics controllers
 *
 *  This driver needs a DirectFB counterpart in user space, communication
 *  is handled via mmap()ed memory areas and an ioctl.
 *
 *  Copyright (c) 2009 Daniel Mack <daniel@caiaq.de>
 *  Copyright (c) 2009 Janine Kropp <nin@directfb.org>
 *  Copyright (c) 2009 Denis Oliver Kropp <dok@directfb.org>
 *
 *  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.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  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.
 */

/*
 * WARNING: This controller is attached to System Bus 2 of the PXA which
 * needs its arbiter to be enabled explicitly (CKENB & 1<<9).
 * There is currently no way to do this from Linux, so you need to teach
 * your bootloader for now.
 */

#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/dma-mapping.h>
#include <linux/miscdevice.h>
#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <linux/uaccess.h>
#include <linux/ioctl.h>
#include <linux/delay.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/clk.h>
#include <linux/fs.h>
#include <linux/io.h>

#include "pxa3xx-gcu.h"


#define DRV_NAME	"pxa3xx-gcu"

#define MISCDEV_MINOR	197


#define REG_GCCR	0x00

#define GCCR_SYNC_CLR	(1 << 9)

#define GCCR_BP_RST	(1 << 8)

#define GCCR_ABORT	(1 << 6)

#define GCCR_STOP	(1 << 4)


#define REG_GCISCR	0x04

#define REG_GCIECR	0x08

#define REG_GCRBBR	0x20

#define REG_GCRBLR	0x24

#define REG_GCRBHR	0x28

#define REG_GCRBTR	0x2C

#define REG_GCRBEXHR	0x30


#define IE_EOB		(1 << 0)

#define IE_EEOB		(1 << 5)

#define IE_ALL		0xff


#define SHARED_SIZE	PAGE_ALIGN(sizeof(struct pxa3xx_gcu_shared))

/* #define PXA3XX_GCU_DEBUG */
/* #define PXA3XX_GCU_DEBUG_TIMER */

#ifdef PXA3XX_GCU_DEBUG

#define QDUMP(msg)					\
	do {                                            \
                QPRINT(priv, KERN_DEBUG, msg);          \
        } while (0)
#else

#define QDUMP(msg)	do {} while (0)
#endif


#define QERROR(msg)					\
	do {                                            \
                QPRINT(priv, KERN_ERR, msg);            \
        } while (0)


struct pxa3xx_gcu_batch {
	
struct pxa3xx_gcu_batch *next;
	
u32			*ptr;
	
dma_addr_t		 phys;
	
unsigned long		 length;
};


struct pxa3xx_gcu_priv {
	
void __iomem		 *mmio_base;
	
struct clk		 *clk;
	
struct pxa3xx_gcu_shared *shared;
	
dma_addr_t		  shared_phys;
	
struct resource		 *resource_mem;
	
struct miscdevice	  misc_dev;
	
wait_queue_head_t	  wait_idle;
	
wait_queue_head_t	  wait_free;
	
spinlock_t		  spinlock;
	
struct timeval 		  base_time;

	
struct pxa3xx_gcu_batch *free;
	
struct pxa3xx_gcu_batch *ready;
	
struct pxa3xx_gcu_batch *ready_last;
	
struct pxa3xx_gcu_batch *running;
};


static inline unsigned long gc_readl(struct pxa3xx_gcu_priv *priv, unsigned int off) { return __raw_readl(priv->mmio_base + off); }

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static inline void gc_writel(struct pxa3xx_gcu_priv *priv, unsigned int off, unsigned long val) { __raw_writel(val, priv->mmio_base + off); }

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#define QPRINT(priv, level, msg) \ do { \ struct timeval tv; \ struct pxa3xx_gcu_shared *shared = priv->shared; \ u32 base = gc_readl(priv, REG_GCRBBR); \ \ do_gettimeofday(&tv); \ \ printk(level "%ld.%03ld.%03ld - %-17s: %-21s (%s, " \ "STATUS " \ "0x%02lx, B 0x%08lx [%ld], E %5ld, H %5ld, " \ "T %5ld)\n", \ tv.tv_sec - priv->base_time.tv_sec, \ tv.tv_usec / 1000, tv.tv_usec % 1000, \ __func__, msg, \ shared->hw_running ? "running" : " idle", \ gc_readl(priv, REG_GCISCR), \ gc_readl(priv, REG_GCRBBR), \ gc_readl(priv, REG_GCRBLR), \ (gc_readl(priv, REG_GCRBEXHR) - base) / 4, \ (gc_readl(priv, REG_GCRBHR) - base) / 4, \ (gc_readl(priv, REG_GCRBTR) - base) / 4); \ } while (0)
static void pxa3xx_gcu_reset(struct pxa3xx_gcu_priv *priv) { QDUMP("RESET"); /* disable interrupts */ gc_writel(priv, REG_GCIECR, 0); /* reset hardware */ gc_writel(priv, REG_GCCR, GCCR_ABORT); gc_writel(priv, REG_GCCR, 0); memset(priv->shared, 0, SHARED_SIZE); priv->shared->buffer_phys = priv->shared_phys; priv->shared->magic = PXA3XX_GCU_SHARED_MAGIC; do_gettimeofday(&priv->base_time); /* set up the ring buffer pointers */ gc_writel(priv, REG_GCRBLR, 0); gc_writel(priv, REG_GCRBBR, priv->shared_phys); gc_writel(priv, REG_GCRBTR, priv->shared_phys); /* enable all IRQs except EOB */ gc_writel(priv, REG_GCIECR, IE_ALL & ~IE_EOB); }

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static void dump_whole_state(struct pxa3xx_gcu_priv *priv) { struct pxa3xx_gcu_shared *sh = priv->shared; u32 base = gc_readl(priv, REG_GCRBBR); QDUMP("DUMP"); printk(KERN_DEBUG "== PXA3XX-GCU DUMP ==\n" "%s, STATUS 0x%02lx, B 0x%08lx [%ld], E %5ld, H %5ld, T %5ld\n", sh->hw_running ? "running" : "idle ", gc_readl(priv, REG_GCISCR), gc_readl(priv, REG_GCRBBR), gc_readl(priv, REG_GCRBLR), (gc_readl(priv, REG_GCRBEXHR) - base) / 4, (gc_readl(priv, REG_GCRBHR) - base) / 4, (gc_readl(priv, REG_GCRBTR) - base) / 4); }

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static void flush_running(struct pxa3xx_gcu_priv *priv) { struct pxa3xx_gcu_batch *running = priv->running; struct pxa3xx_gcu_batch *next; while (running) { next = running->next; running->next = priv->free; priv->free = running; running = next; } priv->running = NULL; }

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static void run_ready(struct pxa3xx_gcu_priv *priv) { unsigned int num = 0; struct pxa3xx_gcu_shared *shared = priv->shared; struct pxa3xx_gcu_batch *ready = priv->ready; QDUMP("Start"); BUG_ON(!ready); shared->buffer[num++] = 0x05000000; while (ready) { shared->buffer[num++] = 0x00000001; shared->buffer[num++] = ready->phys; ready = ready->next; } shared->buffer[num++] = 0x05000000; priv->running = priv->ready; priv->ready = priv->ready_last = NULL; gc_writel(priv, REG_GCRBLR, 0); shared->hw_running = 1; /* ring base address */ gc_writel(priv, REG_GCRBBR, shared->buffer_phys); /* ring tail address */ gc_writel(priv, REG_GCRBTR, shared->buffer_phys + num * 4); /* ring length */ gc_writel(priv, REG_GCRBLR, ((num + 63) & ~63) * 4); }

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static irqreturn_t pxa3xx_gcu_handle_irq(int irq, void *ctx) { struct pxa3xx_gcu_priv *priv = ctx; struct pxa3xx_gcu_shared *shared = priv->shared; u32 status = gc_readl(priv, REG_GCISCR) & IE_ALL; QDUMP("-Interrupt"); if (!status) return IRQ_NONE; spin_lock(&priv->spinlock); shared->num_interrupts++; if (status & IE_EEOB) { QDUMP(" [EEOB]"); flush_running(priv); wake_up_all(&priv->wait_free); if (priv->ready) { run_ready(priv); } else { /* There is no more data prepared by the userspace. * Set hw_running = 0 and wait for the next userspace * kick-off */ shared->num_idle++; shared->hw_running = 0; QDUMP(" '-> Idle."); /* set ring buffer length to zero */ gc_writel(priv, REG_GCRBLR, 0); wake_up_all(&priv->wait_idle); } shared->num_done++; } else { QERROR(" [???]"); dump_whole_state(priv); } /* Clear the interrupt */ gc_writel(priv, REG_GCISCR, status); spin_unlock(&priv->spinlock); return IRQ_HANDLED; }

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static int pxa3xx_gcu_wait_idle(struct pxa3xx_gcu_priv *priv) { int ret = 0; QDUMP("Waiting for idle..."); /* Does not need to be atomic. There's a lock in user space, * but anyhow, this is just for statistics. */ priv->shared->num_wait_idle++; while (priv->shared->hw_running) { int num = priv->shared->num_interrupts; u32 rbexhr = gc_readl(priv, REG_GCRBEXHR); ret = wait_event_interruptible_timeout(priv->wait_idle, !priv->shared->hw_running, HZ*4); if (ret != 0) break; if (gc_readl(priv, REG_GCRBEXHR) == rbexhr && priv->shared->num_interrupts == num) { QERROR("TIMEOUT"); ret = -ETIMEDOUT; break; } } QDUMP("done"); return ret; }

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static int pxa3xx_gcu_wait_free(struct pxa3xx_gcu_priv *priv) { int ret = 0; QDUMP("Waiting for free..."); /* Does not need to be atomic. There's a lock in user space, * but anyhow, this is just for statistics. */ priv->shared->num_wait_free++; while (!priv->free) { u32 rbexhr = gc_readl(priv, REG_GCRBEXHR); ret = wait_event_interruptible_timeout(priv->wait_free, priv->free, HZ*4); if (ret < 0) break; if (ret > 0) continue; if (gc_readl(priv, REG_GCRBEXHR) == rbexhr) { QERROR("TIMEOUT"); ret = -ETIMEDOUT; break; } } QDUMP("done"); return ret; }

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/* Misc device layer */
static inline struct pxa3xx_gcu_priv *to_pxa3xx_gcu_priv(struct file *file) { struct miscdevice *dev = file->private_data; return container_of(dev, struct pxa3xx_gcu_priv, misc_dev); }

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Al Viro3397.06%150.00%
Daniel Mack12.94%150.00%
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/* * provide an empty .open callback, so the core sets file->private_data * for us. */
static int pxa3xx_gcu_open(struct inode *inode, struct file *file) { return 0; }

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static ssize_t pxa3xx_gcu_write(struct file *file, const char *buff, size_t count, loff_t *offp) { int ret; unsigned long flags; struct pxa3xx_gcu_batch *buffer; struct pxa3xx_gcu_priv *priv = to_pxa3xx_gcu_priv(file); int words = count / 4; /* Does not need to be atomic. There's a lock in user space, * but anyhow, this is just for statistics. */ priv->shared->num_writes++; priv->shared->num_words += words; /* Last word reserved for batch buffer end command */ if (words >= PXA3XX_GCU_BATCH_WORDS) return -E2BIG; /* Wait for a free buffer */ if (!priv->free) { ret = pxa3xx_gcu_wait_free(priv); if (ret < 0) return ret; } /* * Get buffer from free list */ spin_lock_irqsave(&priv->spinlock, flags); buffer = priv->free; priv->free = buffer->next; spin_unlock_irqrestore(&priv->spinlock, flags); /* Copy data from user into buffer */ ret = copy_from_user(buffer->ptr, buff, words * 4); if (ret) { spin_lock_irqsave(&priv->spinlock, flags); buffer->next = priv->free; priv->free = buffer; spin_unlock_irqrestore(&priv->spinlock, flags); return -EFAULT; } buffer->length = words; /* Append batch buffer end command */ buffer->ptr[words] = 0x01000000; /* * Add buffer to ready list */ spin_lock_irqsave(&priv->spinlock, flags); buffer->next = NULL; if (priv->ready) { BUG_ON(priv->ready_last == NULL); priv->ready_last->next = buffer; } else priv->ready = buffer; priv->ready_last = buffer; if (!priv->shared->hw_running) run_ready(priv); spin_unlock_irqrestore(&priv->spinlock, flags); return words * 4; }

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Daniel Mack29698.67%250.00%
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static long pxa3xx_gcu_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { unsigned long flags; struct pxa3xx_gcu_priv *priv = to_pxa3xx_gcu_priv(file); switch (cmd) { case PXA3XX_GCU_IOCTL_RESET: spin_lock_irqsave(&priv->spinlock, flags); pxa3xx_gcu_reset(priv); spin_unlock_irqrestore(&priv->spinlock, flags); return 0; case PXA3XX_GCU_IOCTL_WAIT_IDLE: return pxa3xx_gcu_wait_idle(priv); } return -ENOSYS; }

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Daniel Mack8197.59%266.67%
Al Viro22.41%133.33%
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static int pxa3xx_gcu_mmap(struct file *file, struct vm_area_struct *vma) { unsigned int size = vma->vm_end - vma->vm_start; struct pxa3xx_gcu_priv *priv = to_pxa3xx_gcu_priv(file); switch (vma->vm_pgoff) { case 0: /* hand out the shared data area */ if (size != SHARED_SIZE) return -EINVAL; return dma_mmap_coherent(NULL, vma, priv->shared, priv->shared_phys, size); case SHARED_SIZE >> PAGE_SHIFT: /* hand out the MMIO base for direct register access * from userspace */ if (size != resource_size(priv->resource_mem)) return -EINVAL; vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); return io_remap_pfn_range(vma, vma->vm_start, priv->resource_mem->start >> PAGE_SHIFT, size, vma->vm_page_prot); } return -EINVAL; }

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#ifdef PXA3XX_GCU_DEBUG_TIMER static struct timer_list pxa3xx_gcu_debug_timer;
static void pxa3xx_gcu_debug_timedout(unsigned long ptr) { struct pxa3xx_gcu_priv *priv = (struct pxa3xx_gcu_priv *) ptr; QERROR("Timer DUMP"); /* init the timer structure */ init_timer(&pxa3xx_gcu_debug_timer); pxa3xx_gcu_debug_timer.function = pxa3xx_gcu_debug_timedout; pxa3xx_gcu_debug_timer.data = ptr; pxa3xx_gcu_debug_timer.expires = jiffies + 5*HZ; /* one second */ add_timer(&pxa3xx_gcu_debug_timer); }

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static void pxa3xx_gcu_init_debug_timer(void) { pxa3xx_gcu_debug_timedout((unsigned long) &pxa3xx_gcu_debug_timer); }

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#else
static inline void pxa3xx_gcu_init_debug_timer(void) {}

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#endif
static int pxa3xx_gcu_add_buffer(struct device *dev, struct pxa3xx_gcu_priv *priv) { struct pxa3xx_gcu_batch *buffer; buffer = kzalloc(sizeof(struct pxa3xx_gcu_batch), GFP_KERNEL); if (!buffer) return -ENOMEM; buffer->ptr = dma_alloc_coherent(dev, PXA3XX_GCU_BATCH_WORDS * 4, &buffer->phys, GFP_KERNEL); if (!buffer->ptr) { kfree(buffer); return -ENOMEM; } buffer->next = priv->free; priv->free = buffer; return 0; }

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static void pxa3xx_gcu_free_buffers(struct device *dev, struct pxa3xx_gcu_priv *priv) { struct pxa3xx_gcu_batch *next, *buffer = priv->free; while (buffer) { next = buffer->next; dma_free_coherent(dev, PXA3XX_GCU_BATCH_WORDS * 4, buffer->ptr, buffer->phys); kfree(buffer); buffer = next; } priv->free = NULL; }

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static const struct file_operations pxa3xx_gcu_miscdev_fops = { .owner = THIS_MODULE, .open = pxa3xx_gcu_open, .write = pxa3xx_gcu_write, .unlocked_ioctl = pxa3xx_gcu_ioctl, .mmap = pxa3xx_gcu_mmap, };
static int pxa3xx_gcu_probe(struct platform_device *pdev) { int i, ret, irq; struct resource *r; struct pxa3xx_gcu_priv *priv; struct device *dev = &pdev->dev; priv = devm_kzalloc(dev, sizeof(struct pxa3xx_gcu_priv), GFP_KERNEL); if (!priv) return -ENOMEM; init_waitqueue_head(&priv->wait_idle); init_waitqueue_head(&priv->wait_free); spin_lock_init(&priv->spinlock); /* we allocate the misc device structure as part of our own allocation, * so we can get a pointer to our priv structure later on with * container_of(). This isn't really necessary as we have a fixed minor * number anyway, but this is to avoid statics. */ priv->misc_dev.minor = MISCDEV_MINOR, priv->misc_dev.name = DRV_NAME, priv->misc_dev.fops = &pxa3xx_gcu_miscdev_fops; /* handle IO resources */ r = platform_get_resource(pdev, IORESOURCE_MEM, 0); priv->mmio_base = devm_ioremap_resource(dev, r); if (IS_ERR(priv->mmio_base)) return PTR_ERR(priv->mmio_base); /* enable the clock */ priv->clk = devm_clk_get(dev, NULL); if (IS_ERR(priv->clk)) { dev_err(dev, "failed to get clock\n"); return PTR_ERR(priv->clk); } /* request the IRQ */ irq = platform_get_irq(pdev, 0); if (irq < 0) { dev_err(dev, "no IRQ defined\n"); return -ENODEV; } ret = devm_request_irq(dev, irq, pxa3xx_gcu_handle_irq, 0, DRV_NAME, priv); if (ret < 0) { dev_err(dev, "request_irq failed\n"); return ret; } /* allocate dma memory */ priv->shared = dma_alloc_coherent(dev, SHARED_SIZE, &priv->shared_phys, GFP_KERNEL); if (!priv->shared) { dev_err(dev, "failed to allocate DMA memory\n"); return -ENOMEM; } /* register misc device */ ret = misc_register(&priv->misc_dev); if (ret < 0) { dev_err(dev, "misc_register() for minor %d failed\n", MISCDEV_MINOR); goto err_free_dma; } ret = clk_prepare_enable(priv->clk); if (ret < 0) { dev_err(dev, "failed to enable clock\n"); goto err_misc_deregister; } for (i = 0; i < 8; i++) { ret = pxa3xx_gcu_add_buffer(dev, priv); if (ret) { dev_err(dev, "failed to allocate DMA memory\n"); goto err_disable_clk; } } platform_set_drvdata(pdev, priv); priv->resource_mem = r; pxa3xx_gcu_reset(priv); pxa3xx_gcu_init_debug_timer(); dev_info(dev, "registered @0x%p, DMA 0x%p (%d bytes), IRQ %d\n", (void *) r->start, (void *) priv->shared_phys, SHARED_SIZE, irq); return 0; err_free_dma: dma_free_coherent(dev, SHARED_SIZE, priv->shared, priv->shared_phys); err_misc_deregister: misc_deregister(&priv->misc_dev); err_disable_clk: clk_disable_unprepare(priv->clk); return ret; }

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static int pxa3xx_gcu_remove(struct platform_device *pdev) { struct pxa3xx_gcu_priv *priv = platform_get_drvdata(pdev); struct device *dev = &pdev->dev; pxa3xx_gcu_wait_idle(priv); misc_deregister(&priv->misc_dev); dma_free_coherent(dev, SHARED_SIZE, priv->shared, priv->shared_phys); pxa3xx_gcu_free_buffers(dev, priv); return 0; }

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static struct platform_driver pxa3xx_gcu_driver = { .probe = pxa3xx_gcu_probe, .remove = pxa3xx_gcu_remove, .driver = { .name = DRV_NAME, }, }; module_platform_driver(pxa3xx_gcu_driver); MODULE_DESCRIPTION("PXA3xx graphics controller unit driver"); MODULE_LICENSE("GPL"); MODULE_ALIAS_MISCDEV(MISCDEV_MINOR); MODULE_AUTHOR("Janine Kropp <nin@directfb.org>, " "Denis Oliver Kropp <dok@directfb.org>, " "Daniel Mack <daniel@caiaq.de>");

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Daniel Mack261897.32%538.46%
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Axel Lin60.22%323.08%
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Lucas De Marchi10.04%17.69%
Jingoo Han10.04%17.69%
Greg Kroah-Hartman0.00%00.00%
Total2690100.00%13100.00%
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