1 files changed, 382 insertions, 0 deletions
diff --git a/drivers/soc/ixp4xx/ixp4xx-qmgr.c b/drivers/soc/ixp4xx/ixp4xx-qmgr.c
new file mode 100644
index 000000000000..2e6d33534afe
--- /dev/null
+++ b/drivers/soc/ixp4xx/ixp4xx-qmgr.c
@@ -0,0 +1,382 @@
+/*
+ * 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 <linux/of.h>
+#include <mach/qmgr.h>
+
+/* FIXME: get rid of these static assigments */
+#define IRQ_IXP4XX_BASE		16
+#define IRQ_IXP4XX_QM1		(IRQ_IXP4XX_BASE + 3)
+#define IRQ_IXP4XX_QM2		(IRQ_IXP4XX_BASE + 4)
+
+static struct qmgr_regs __iomem *qmgr_regs = IXP4XX_QMGR_BASE_VIRT;
+static struct resource *mem_res;
+static spinlock_t qmgr_lock;
+static u32 used_sram_bitmap[4]; /* 128 16-dword pages */
+static void (*irq_handlers[QUEUES])(void *pdev);
+static void *irq_pdevs[QUEUES];
+
+#if DEBUG_QMGR
+char qmgr_queue_descs[QUEUES][32];
+#endif
+
+void qmgr_set_irq(unsigned int queue, int src,
+		  void (*handler)(void *pdev), void *pdev)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&qmgr_lock, flags);
+	if (queue < HALF_QUEUES) {
+		u32 __iomem *reg;
+		int bit;
+		BUG_ON(src > QUEUE_IRQ_SRC_NOT_FULL);
+		reg = &qmgr_regs->irqsrc[queue >> 3]; /* 8 queues per u32 */
+		bit = (queue % 8) * 4; /* 3 bits + 1 reserved bit per queue */
+		__raw_writel((__raw_readl(reg) & ~(7 << bit)) | (src << bit),
+			     reg);
+	} else
+		/* IRQ source for queues 32-63 is fixed */
+		BUG_ON(src != QUEUE_IRQ_SRC_NOT_NEARLY_EMPTY);
+
+	irq_handlers[queue] = handler;
+	irq_pdevs[queue] = pdev;
+	spin_unlock_irqrestore(&qmgr_lock, flags);
+}
+
+
+static irqreturn_t qmgr_irq1_a0(int irq, void *pdev)
+{
+	int i, ret = 0;
+	u32 en_bitmap, src, stat;
+
+	/* ACK - it may clear any bits so don't rely on it */
+	__raw_writel(0xFFFFFFFF, &qmgr_regs->irqstat[0]);
+
+	en_bitmap = qmgr_regs->irqen[0];
+	while (en_bitmap) {
+		i = __fls(en_bitmap); /* number of the last "low" queue */
+		en_bitmap &= ~BIT(i);
+		src = qmgr_regs->irqsrc[i >> 3];
+		stat = qmgr_regs->stat1[i >> 3];
+		if (src & 4) /* the IRQ condition is inverted */
+			stat = ~stat;
+		if (stat & BIT(src & 3)) {
+			irq_handlers[i](irq_pdevs[i]);
+			ret = IRQ_HANDLED;
+		}
+	}
+	return ret;
+}
+
+
+static irqreturn_t qmgr_irq2_a0(int irq, void *pdev)
+{
+	int i, ret = 0;
+	u32 req_bitmap;
+
+	/* ACK - it may clear any bits so don't rely on it */
+	__raw_writel(0xFFFFFFFF, &qmgr_regs->irqstat[1]);
+
+	req_bitmap = qmgr_regs->irqen[1] & qmgr_regs->statne_h;
+	while (req_bitmap) {
+		i = __fls(req_bitmap); /* number of the last "high" queue */
+		req_bitmap &= ~BIT(i);
+		irq_handlers[HALF_QUEUES + i](irq_pdevs[HALF_QUEUES + i]);
+		ret = IRQ_HANDLED;
+	}
+	return ret;
+}
+
+
+static irqreturn_t qmgr_irq(int irq, void *pdev)
+{
+	int i, half = (irq == IRQ_IXP4XX_QM1 ? 0 : 1);
+	u32 req_bitmap = __raw_readl(&qmgr_regs->irqstat[half]);
+
+	if (!req_bitmap)
+		return 0;
+	__raw_writel(req_bitmap, &qmgr_regs->irqstat[half]); /* ACK */
+
+	while (req_bitmap) {
+		i = __fls(req_bitmap); /* number of the last queue */
+		req_bitmap &= ~BIT(i);
+		i += half * HALF_QUEUES;
+		irq_handlers[i](irq_pdevs[i]);
+	}
+	return IRQ_HANDLED;
+}
+
+
+void qmgr_enable_irq(unsigned int queue)
+{
+	unsigned long flags;
+	int half = queue / 32;
+	u32 mask = 1 << (queue & (HALF_QUEUES - 1));
+
+	spin_lock_irqsave(&qmgr_lock, flags);
+	__raw_writel(__raw_readl(&qmgr_regs->irqen[half]) | mask,
+		     &qmgr_regs->irqen[half]);
+	spin_unlock_irqrestore(&qmgr_lock, flags);
+}
+
+void qmgr_disable_irq(unsigned int queue)
+{
+	unsigned long flags;
+	int half = queue / 32;
+	u32 mask = 1 << (queue & (HALF_QUEUES - 1));
+
+	spin_lock_irqsave(&qmgr_lock, flags);
+	__raw_writel(__raw_readl(&qmgr_regs->irqen[half]) & ~mask,
+		     &qmgr_regs->irqen[half]);
+	__raw_writel(mask, &qmgr_regs->irqstat[half]); /* clear */
+	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;
+}
+
+#if DEBUG_QMGR
+int qmgr_request_queue(unsigned int queue, unsigned int len /* dwords */,
+		       unsigned int nearly_empty_watermark,
+		       unsigned int nearly_full_watermark,
+		       const char *desc_format, const char* name)
+#else
+int __qmgr_request_queue(unsigned int queue, unsigned int len /* dwords */,
+			 unsigned int nearly_empty_watermark,
+			 unsigned int nearly_full_watermark)
+#endif
+{
+	u32 cfg, addr = 0, mask[4]; /* in 16-dwords */
+	int err;
+
+	BUG_ON(queue >= QUEUES);
+
+	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]);
+#if DEBUG_QMGR
+	snprintf(qmgr_queue_descs[queue], sizeof(qmgr_queue_descs[0]),
+		 desc_format, name);
+	printk(KERN_DEBUG "qmgr: requested queue %s(%i) addr = 0x%02X\n",
+	       qmgr_queue_descs[queue], queue, addr);
+#endif
+	spin_unlock_irq(&qmgr_lock);
+	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 >= 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;
+	}
+
+	mask[1] = mask[2] = mask[3] = 0;
+
+	while (addr--)
+		shift_mask(mask);
+
+#if DEBUG_QMGR
+	printk(KERN_DEBUG "qmgr: releasing queue %s(%i)\n",
+	       qmgr_queue_descs[queue], queue);
+	qmgr_queue_descs[queue][0] = '\x0';
+#endif
+
+	while ((addr = qmgr_get_entry(queue)))
+		printk(KERN_ERR "qmgr: released queue %i not empty: 0x%08X\n",
+		       queue, addr);
+
+	__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);
+}
+
+static int qmgr_init(void)
+{
+	int i, err;
+	irq_handler_t handler1, handler2;
+
+	/* This driver does not work with device tree */
+	if (of_have_populated_dt())
+		return -ENODEV;
+
+	mem_res = request_mem_region(IXP4XX_QMGR_BASE_PHYS,
+				     IXP4XX_QMGR_REGION_SIZE,
+				     "IXP4xx Queue Manager");
+	if (mem_res == NULL)
+		return -EBUSY;
+
+	/* 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]);
+	}
+
+	__raw_writel(0xFFFFFFFF, &qmgr_regs->statne_h);
+	__raw_writel(0, &qmgr_regs->statf_h);
+
+	for (i = 0; i < QUEUES; i++)
+		__raw_writel(0, &qmgr_regs->sram[i]);
+
+	if (cpu_is_ixp42x_rev_a0()) {
+		handler1 = qmgr_irq1_a0;
+		handler2 = qmgr_irq2_a0;
+	} else
+		handler1 = handler2 = qmgr_irq;
+
+	err = request_irq(IRQ_IXP4XX_QM1, handler1, 0, "IXP4xx Queue Manager",
+			  NULL);
+	if (err) {
+		printk(KERN_ERR "qmgr: failed to request IRQ%i (%i)\n",
+		       IRQ_IXP4XX_QM1, err);
+		goto error_irq;
+	}
+
+	err = request_irq(IRQ_IXP4XX_QM2, handler2, 0, "IXP4xx Queue Manager",
+			  NULL);
+	if (err) {
+		printk(KERN_ERR "qmgr: failed to request IRQ%i (%i)\n",
+		       IRQ_IXP4XX_QM2, err);
+		goto error_irq2;
+	}
+
+	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_irq2:
+	free_irq(IRQ_IXP4XX_QM1, NULL);
+error_irq:
+	release_mem_region(IXP4XX_QMGR_BASE_PHYS, IXP4XX_QMGR_REGION_SIZE);
+	return err;
+}
+
+static void qmgr_remove(void)
+{
+	free_irq(IRQ_IXP4XX_QM1, NULL);
+	free_irq(IRQ_IXP4XX_QM2, NULL);
+	synchronize_irq(IRQ_IXP4XX_QM1);
+	synchronize_irq(IRQ_IXP4XX_QM2);
+	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_set_irq);
+EXPORT_SYMBOL(qmgr_enable_irq);
+EXPORT_SYMBOL(qmgr_disable_irq);
+#if DEBUG_QMGR
+EXPORT_SYMBOL(qmgr_queue_descs);
+EXPORT_SYMBOL(qmgr_request_queue);
+#else
+EXPORT_SYMBOL(__qmgr_request_queue);
+#endif
+EXPORT_SYMBOL(qmgr_release_queue);