diff options
Diffstat (limited to 'arch/arm/mach-ixp4xx/ixp4xx_qmgr.c')
| -rw-r--r-- | arch/arm/mach-ixp4xx/ixp4xx_qmgr.c | 274 |
1 files changed, 274 insertions, 0 deletions
diff --git a/arch/arm/mach-ixp4xx/ixp4xx_qmgr.c b/arch/arm/mach-ixp4xx/ixp4xx_qmgr.c new file mode 100644 index 00000000000..e8330132530 --- /dev/null +++ b/arch/arm/mach-ixp4xx/ixp4xx_qmgr.c @@ -0,0 +1,274 @@ +/* + * Intel IXP4xx Queue Manager driver for Linux + * + * Copyright (C) 2007 Krzysztof Halasa <khc@pm.waw.pl> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of version 2 of the GNU General Public License + * as published by the Free Software Foundation. + */ + +#include <linux/ioport.h> +#include <linux/interrupt.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <asm/arch/qmgr.h> + +#define DEBUG 0 + +struct qmgr_regs __iomem *qmgr_regs; +static struct resource *mem_res; +static spinlock_t qmgr_lock; +static u32 used_sram_bitmap[4]; /* 128 16-dword pages */ +static void (*irq_handlers[HALF_QUEUES])(void *pdev); +static void *irq_pdevs[HALF_QUEUES]; + +void qmgr_set_irq(unsigned int queue, int src, + void (*handler)(void *pdev), void *pdev) +{ + u32 __iomem *reg = &qmgr_regs->irqsrc[queue / 8]; /* 8 queues / u32 */ + int bit = (queue % 8) * 4; /* 3 bits + 1 reserved bit per queue */ + unsigned long flags; + + src &= 7; + spin_lock_irqsave(&qmgr_lock, flags); + __raw_writel((__raw_readl(reg) & ~(7 << bit)) | (src << bit), reg); + irq_handlers[queue] = handler; + irq_pdevs[queue] = pdev; + spin_unlock_irqrestore(&qmgr_lock, flags); +} + + +static irqreturn_t qmgr_irq1(int irq, void *pdev) +{ + int i; + u32 val = __raw_readl(&qmgr_regs->irqstat[0]); + __raw_writel(val, &qmgr_regs->irqstat[0]); /* ACK */ + + for (i = 0; i < HALF_QUEUES; i++) + if (val & (1 << i)) + irq_handlers[i](irq_pdevs[i]); + + return val ? IRQ_HANDLED : 0; +} + + +void qmgr_enable_irq(unsigned int queue) +{ + unsigned long flags; + + spin_lock_irqsave(&qmgr_lock, flags); + __raw_writel(__raw_readl(&qmgr_regs->irqen[0]) | (1 << queue), + &qmgr_regs->irqen[0]); + spin_unlock_irqrestore(&qmgr_lock, flags); +} + +void qmgr_disable_irq(unsigned int queue) +{ + unsigned long flags; + + spin_lock_irqsave(&qmgr_lock, flags); + __raw_writel(__raw_readl(&qmgr_regs->irqen[0]) & ~(1 << queue), + &qmgr_regs->irqen[0]); + spin_unlock_irqrestore(&qmgr_lock, flags); +} + +static inline void shift_mask(u32 *mask) +{ + mask[3] = mask[3] << 1 | mask[2] >> 31; + mask[2] = mask[2] << 1 | mask[1] >> 31; + mask[1] = mask[1] << 1 | mask[0] >> 31; + mask[0] <<= 1; +} + +int qmgr_request_queue(unsigned int queue, unsigned int len /* dwords */, + unsigned int nearly_empty_watermark, + unsigned int nearly_full_watermark) +{ + u32 cfg, addr = 0, mask[4]; /* in 16-dwords */ + int err; + + if (queue >= HALF_QUEUES) + return -ERANGE; + + if ((nearly_empty_watermark | nearly_full_watermark) & ~7) + return -EINVAL; + + switch (len) { + case 16: + cfg = 0 << 24; + mask[0] = 0x1; + break; + case 32: + cfg = 1 << 24; + mask[0] = 0x3; + break; + case 64: + cfg = 2 << 24; + mask[0] = 0xF; + break; + case 128: + cfg = 3 << 24; + mask[0] = 0xFF; + break; + default: + return -EINVAL; + } + + cfg |= nearly_empty_watermark << 26; + cfg |= nearly_full_watermark << 29; + len /= 16; /* in 16-dwords: 1, 2, 4 or 8 */ + mask[1] = mask[2] = mask[3] = 0; + + if (!try_module_get(THIS_MODULE)) + return -ENODEV; + + spin_lock_irq(&qmgr_lock); + if (__raw_readl(&qmgr_regs->sram[queue])) { + err = -EBUSY; + goto err; + } + + while (1) { + if (!(used_sram_bitmap[0] & mask[0]) && + !(used_sram_bitmap[1] & mask[1]) && + !(used_sram_bitmap[2] & mask[2]) && + !(used_sram_bitmap[3] & mask[3])) + break; /* found free space */ + + addr++; + shift_mask(mask); + if (addr + len > ARRAY_SIZE(qmgr_regs->sram)) { + printk(KERN_ERR "qmgr: no free SRAM space for" + " queue %i\n", queue); + err = -ENOMEM; + goto err; + } + } + + used_sram_bitmap[0] |= mask[0]; + used_sram_bitmap[1] |= mask[1]; + used_sram_bitmap[2] |= mask[2]; + used_sram_bitmap[3] |= mask[3]; + __raw_writel(cfg | (addr << 14), &qmgr_regs->sram[queue]); + spin_unlock_irq(&qmgr_lock); + +#if DEBUG + printk(KERN_DEBUG "qmgr: requested queue %i, addr = 0x%02X\n", + queue, addr); +#endif + return 0; + +err: + spin_unlock_irq(&qmgr_lock); + module_put(THIS_MODULE); + return err; +} + +void qmgr_release_queue(unsigned int queue) +{ + u32 cfg, addr, mask[4]; + + BUG_ON(queue >= HALF_QUEUES); /* not in valid range */ + + spin_lock_irq(&qmgr_lock); + cfg = __raw_readl(&qmgr_regs->sram[queue]); + addr = (cfg >> 14) & 0xFF; + + BUG_ON(!addr); /* not requested */ + + switch ((cfg >> 24) & 3) { + case 0: mask[0] = 0x1; break; + case 1: mask[0] = 0x3; break; + case 2: mask[0] = 0xF; break; + case 3: mask[0] = 0xFF; break; + } + + while (addr--) + shift_mask(mask); + + __raw_writel(0, &qmgr_regs->sram[queue]); + + used_sram_bitmap[0] &= ~mask[0]; + used_sram_bitmap[1] &= ~mask[1]; + used_sram_bitmap[2] &= ~mask[2]; + used_sram_bitmap[3] &= ~mask[3]; + irq_handlers[queue] = NULL; /* catch IRQ bugs */ + spin_unlock_irq(&qmgr_lock); + + module_put(THIS_MODULE); +#if DEBUG + printk(KERN_DEBUG "qmgr: released queue %i\n", queue); +#endif +} + +static int qmgr_init(void) +{ + int i, err; + mem_res = request_mem_region(IXP4XX_QMGR_BASE_PHYS, + IXP4XX_QMGR_REGION_SIZE, + "IXP4xx Queue Manager"); + if (mem_res == NULL) + return -EBUSY; + + qmgr_regs = ioremap(IXP4XX_QMGR_BASE_PHYS, IXP4XX_QMGR_REGION_SIZE); + if (qmgr_regs == NULL) { + err = -ENOMEM; + goto error_map; + } + + /* reset qmgr registers */ + for (i = 0; i < 4; i++) { + __raw_writel(0x33333333, &qmgr_regs->stat1[i]); + __raw_writel(0, &qmgr_regs->irqsrc[i]); + } + for (i = 0; i < 2; i++) { + __raw_writel(0, &qmgr_regs->stat2[i]); + __raw_writel(0xFFFFFFFF, &qmgr_regs->irqstat[i]); /* clear */ + __raw_writel(0, &qmgr_regs->irqen[i]); + } + + for (i = 0; i < QUEUES; i++) + __raw_writel(0, &qmgr_regs->sram[i]); + + err = request_irq(IRQ_IXP4XX_QM1, qmgr_irq1, 0, + "IXP4xx Queue Manager", NULL); + if (err) { + printk(KERN_ERR "qmgr: failed to request IRQ%i\n", + IRQ_IXP4XX_QM1); + goto error_irq; + } + + used_sram_bitmap[0] = 0xF; /* 4 first pages reserved for config */ + spin_lock_init(&qmgr_lock); + + printk(KERN_INFO "IXP4xx Queue Manager initialized.\n"); + return 0; + +error_irq: + iounmap(qmgr_regs); +error_map: + release_mem_region(IXP4XX_QMGR_BASE_PHYS, IXP4XX_QMGR_REGION_SIZE); + return err; +} + +static void qmgr_remove(void) +{ + free_irq(IRQ_IXP4XX_QM1, NULL); + synchronize_irq(IRQ_IXP4XX_QM1); + iounmap(qmgr_regs); + release_mem_region(IXP4XX_QMGR_BASE_PHYS, IXP4XX_QMGR_REGION_SIZE); +} + +module_init(qmgr_init); +module_exit(qmgr_remove); + +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("Krzysztof Halasa"); + +EXPORT_SYMBOL(qmgr_regs); +EXPORT_SYMBOL(qmgr_set_irq); +EXPORT_SYMBOL(qmgr_enable_irq); +EXPORT_SYMBOL(qmgr_disable_irq); +EXPORT_SYMBOL(qmgr_request_queue); +EXPORT_SYMBOL(qmgr_release_queue); |