CRIS v32: Add new machine dependent files for Etrax-FS and Artpec-3.

The two chips are somewhat different, and needs different handling.
Adds handing of the dma, dram initialization, hardware settings, io,
memory arbiter and pinmux

Also moves the dma, dram initialization and io from CRIS v32 common files.

1 files changed, 404 insertions, 0 deletions

diff --git a/arch/cris/arch-v32/mach-fs/arbiter.c b/arch/cris/arch-v32/mach-fs/arbiter.c
new file mode 100644
index 00000000000..84d31bd7b69
--- /dev/null
+++ b/arch/cris/arch-v32/mach-fs/arbiter.c
@@ -0,0 +1,404 @@
+/*
+ * Memory arbiter functions. Allocates bandwidth through the
+ * arbiter and sets up arbiter breakpoints.
+ *
+ * The algorithm first assigns slots to the clients that has specified
+ * bandwidth (e.g. ethernet) and then the remaining slots are divided
+ * on all the active clients.
+ *
+ * Copyright (c) 2004-2007 Axis Communications AB.
+ */
+
+#include <hwregs/reg_map.h>
+#include <hwregs/reg_rdwr.h>
+#include <hwregs/marb_defs.h>
+#include <arbiter.h>
+#include <hwregs/intr_vect.h>
+#include <linux/interrupt.h>
+#include <linux/signal.h>
+#include <linux/errno.h>
+#include <linux/spinlock.h>
+#include <asm/io.h>
+#include <asm/irq_regs.h>
+
+struct crisv32_watch_entry {
+	unsigned long instance;
+	watch_callback *cb;
+	unsigned long start;
+	unsigned long end;
+	int used;
+};
+
+#define NUMBER_OF_BP 4
+#define NBR_OF_CLIENTS 14
+#define NBR_OF_SLOTS 64
+#define SDRAM_BANDWIDTH 100000000	/* Some kind of expected value */
+#define INTMEM_BANDWIDTH 400000000
+#define NBR_OF_REGIONS 2
+
+static struct crisv32_watch_entry watches[NUMBER_OF_BP] = {
+	{regi_marb_bp0},
+	{regi_marb_bp1},
+	{regi_marb_bp2},
+	{regi_marb_bp3}
+};
+
+static u8 requested_slots[NBR_OF_REGIONS][NBR_OF_CLIENTS];
+static u8 active_clients[NBR_OF_REGIONS][NBR_OF_CLIENTS];
+static int max_bandwidth[NBR_OF_REGIONS] =
+    { SDRAM_BANDWIDTH, INTMEM_BANDWIDTH };
+
+DEFINE_SPINLOCK(arbiter_lock);
+
+static irqreturn_t crisv32_arbiter_irq(int irq, void *dev_id);
+
+/*
+ * "I'm the arbiter, I know the score.
+ *  From square one I'll be watching all 64."
+ * (memory arbiter slots, that is)
+ *
+ *  Or in other words:
+ * Program the memory arbiter slots for "region" according to what's
+ * in requested_slots[] and active_clients[], while minimizing
+ * latency. A caller may pass a non-zero positive amount for
+ * "unused_slots", which must then be the unallocated, remaining
+ * number of slots, free to hand out to any client.
+ */
+
+static void crisv32_arbiter_config(int region, int unused_slots)
+{
+	int slot;
+	int client;
+	int interval = 0;
+
+	/*
+	 * This vector corresponds to the hardware arbiter slots (see
+	 * the hardware documentation for semantics). We initialize
+	 * each slot with a suitable sentinel value outside the valid
+	 * range {0 .. NBR_OF_CLIENTS - 1} and replace them with
+	 * client indexes. Then it's fed to the hardware.
+	 */
+	s8 val[NBR_OF_SLOTS];
+
+	for (slot = 0; slot < NBR_OF_SLOTS; slot++)
+		val[slot] = -1;
+
+	for (client = 0; client < NBR_OF_CLIENTS; client++) {
+		int pos;
+		/* Allocate the requested non-zero number of slots, but
+		 * also give clients with zero-requests one slot each
+		 * while stocks last. We do the latter here, in client
+		 * order. This makes sure zero-request clients are the
+		 * first to get to any spare slots, else those slots
+		 * could, when bandwidth is allocated close to the limit,
+		 * all be allocated to low-index non-zero-request clients
+		 * in the default-fill loop below. Another positive but
+		 * secondary effect is a somewhat better spread of the
+		 * zero-bandwidth clients in the vector, avoiding some of
+		 * the latency that could otherwise be caused by the
+		 * partitioning of non-zero-bandwidth clients at low
+		 * indexes and zero-bandwidth clients at high
+		 * indexes. (Note that this spreading can only affect the
+		 * unallocated bandwidth.)  All the above only matters for
+		 * memory-intensive situations, of course.
+		 */
+		if (!requested_slots[region][client]) {
+			/*
+			 * Skip inactive clients. Also skip zero-slot
+			 * allocations in this pass when there are no known
+			 * free slots.
+			 */
+			if (!active_clients[region][client]
+			    || unused_slots <= 0)
+				continue;
+
+			unused_slots--;
+
+			/* Only allocate one slot for this client. */
+			interval = NBR_OF_SLOTS;
+		} else
+			interval =
+			    NBR_OF_SLOTS / requested_slots[region][client];
+
+		pos = 0;
+		while (pos < NBR_OF_SLOTS) {
+			if (val[pos] >= 0)
+				pos++;
+			else {
+				val[pos] = client;
+				pos += interval;
+			}
+		}
+	}
+
+	client = 0;
+	for (slot = 0; slot < NBR_OF_SLOTS; slot++) {
+		/*
+		 * Allocate remaining slots in round-robin
+		 * client-number order for active clients. For this
+		 * pass, we ignore requested bandwidth and previous
+		 * allocations.
+		 */
+		if (val[slot] < 0) {
+			int first = client;
+			while (!active_clients[region][client]) {
+				client = (client + 1) % NBR_OF_CLIENTS;
+				if (client == first)
+					break;
+			}
+			val[slot] = client;
+			client = (client + 1) % NBR_OF_CLIENTS;
+		}
+		if (region == EXT_REGION)
+			REG_WR_INT_VECT(marb, regi_marb, rw_ext_slots, slot,
+					val[slot]);
+		else if (region == INT_REGION)
+			REG_WR_INT_VECT(marb, regi_marb, rw_int_slots, slot,
+					val[slot]);
+	}
+}
+
+extern char _stext, _etext;
+
+static void crisv32_arbiter_init(void)
+{
+	static int initialized;
+
+	if (initialized)
+		return;
+
+	initialized = 1;
+
+	/*
+	 * CPU caches are always set to active, but with zero
+	 * bandwidth allocated. It should be ok to allocate zero
+	 * bandwidth for the caches, because DMA for other channels
+	 * will supposedly finish, once their programmed amount is
+	 * done, and then the caches will get access according to the
+	 * "fixed scheme" for unclaimed slots. Though, if for some
+	 * use-case somewhere, there's a maximum CPU latency for
+	 * e.g. some interrupt, we have to start allocating specific
+	 * bandwidth for the CPU caches too.
+	 */
+	active_clients[EXT_REGION][10] = active_clients[EXT_REGION][11] = 1;
+	crisv32_arbiter_config(EXT_REGION, 0);
+	crisv32_arbiter_config(INT_REGION, 0);
+
+	if (request_irq(MEMARB_INTR_VECT, crisv32_arbiter_irq, IRQF_DISABLED,
+			"arbiter", NULL))
+		printk(KERN_ERR "Couldn't allocate arbiter IRQ\n");
+
+#ifndef CONFIG_ETRAX_KGDB
+	/* Global watch for writes to kernel text segment. */
+	crisv32_arbiter_watch(virt_to_phys(&_stext), &_etext - &_stext,
+			      arbiter_all_clients, arbiter_all_write, NULL);
+#endif
+}
+
+/* Main entry for bandwidth allocation. */
+
+int crisv32_arbiter_allocate_bandwidth(int client, int region,
+				       unsigned long bandwidth)
+{
+	int i;
+	int total_assigned = 0;
+	int total_clients = 0;
+	int req;
+
+	crisv32_arbiter_init();
+
+	for (i = 0; i < NBR_OF_CLIENTS; i++) {
+		total_assigned += requested_slots[region][i];
+		total_clients += active_clients[region][i];
+	}
+
+	/* Avoid division by 0 for 0-bandwidth requests. */
+	req = bandwidth == 0
+	    ? 0 : NBR_OF_SLOTS / (max_bandwidth[region] / bandwidth);
+
+	/*
+	 * We make sure that there are enough slots only for non-zero
+	 * requests. Requesting 0 bandwidth *may* allocate slots,
+	 * though if all bandwidth is allocated, such a client won't
+	 * get any and will have to rely on getting memory access
+	 * according to the fixed scheme that's the default when one
+	 * of the slot-allocated clients doesn't claim their slot.
+	 */
+	if (total_assigned + req > NBR_OF_SLOTS)
+		return -ENOMEM;
+
+	active_clients[region][client] = 1;
+	requested_slots[region][client] = req;
+	crisv32_arbiter_config(region, NBR_OF_SLOTS - total_assigned);
+
+	return 0;
+}
+
+/*
+ * Main entry for bandwidth deallocation.
+ *
+ * Strictly speaking, for a somewhat constant set of clients where
+ * each client gets a constant bandwidth and is just enabled or
+ * disabled (somewhat dynamically), no action is necessary here to
+ * avoid starvation for non-zero-allocation clients, as the allocated
+ * slots will just be unused. However, handing out those unused slots
+ * to active clients avoids needless latency if the "fixed scheme"
+ * would give unclaimed slots to an eager low-index client.
+ */
+
+void crisv32_arbiter_deallocate_bandwidth(int client, int region)
+{
+	int i;
+	int total_assigned = 0;
+
+	requested_slots[region][client] = 0;
+	active_clients[region][client] = 0;
+
+	for (i = 0; i < NBR_OF_CLIENTS; i++)
+		total_assigned += requested_slots[region][i];
+
+	crisv32_arbiter_config(region, NBR_OF_SLOTS - total_assigned);
+}
+
+int crisv32_arbiter_watch(unsigned long start, unsigned long size,
+			  unsigned long clients, unsigned long accesses,
+			  watch_callback *cb)
+{
+	int i;
+
+	crisv32_arbiter_init();
+
+	if (start > 0x80000000) {
+		printk(KERN_ERR "Arbiter: %lX doesn't look like a "
+			"physical address", start);
+		return -EFAULT;
+	}
+
+	spin_lock(&arbiter_lock);
+
+	for (i = 0; i < NUMBER_OF_BP; i++) {
+		if (!watches[i].used) {
+			reg_marb_rw_intr_mask intr_mask =
+			    REG_RD(marb, regi_marb, rw_intr_mask);
+
+			watches[i].used = 1;
+			watches[i].start = start;
+			watches[i].end = start + size;
+			watches[i].cb = cb;
+
+			REG_WR_INT(marb_bp, watches[i].instance, rw_first_addr,
+				   watches[i].start);
+			REG_WR_INT(marb_bp, watches[i].instance, rw_last_addr,
+				   watches[i].end);
+			REG_WR_INT(marb_bp, watches[i].instance, rw_op,
+				   accesses);
+			REG_WR_INT(marb_bp, watches[i].instance, rw_clients,
+				   clients);
+
+			if (i == 0)
+				intr_mask.bp0 = regk_marb_yes;
+			else if (i == 1)
+				intr_mask.bp1 = regk_marb_yes;
+			else if (i == 2)
+				intr_mask.bp2 = regk_marb_yes;
+			else if (i == 3)
+				intr_mask.bp3 = regk_marb_yes;
+
+			REG_WR(marb, regi_marb, rw_intr_mask, intr_mask);
+			spin_unlock(&arbiter_lock);
+
+			return i;
+		}
+	}
+	spin_unlock(&arbiter_lock);
+	return -ENOMEM;
+}
+
+int crisv32_arbiter_unwatch(int id)
+{
+	reg_marb_rw_intr_mask intr_mask = REG_RD(marb, regi_marb, rw_intr_mask);
+
+	crisv32_arbiter_init();
+
+	spin_lock(&arbiter_lock);
+
+	if ((id < 0) || (id >= NUMBER_OF_BP) || (!watches[id].used)) {
+		spin_unlock(&arbiter_lock);
+		return -EINVAL;
+	}
+
+	memset(&watches[id], 0, sizeof(struct crisv32_watch_entry));
+
+	if (id == 0)
+		intr_mask.bp0 = regk_marb_no;
+	else if (id == 1)
+		intr_mask.bp2 = regk_marb_no;
+	else if (id == 2)
+		intr_mask.bp2 = regk_marb_no;
+	else if (id == 3)
+		intr_mask.bp3 = regk_marb_no;
+
+	REG_WR(marb, regi_marb, rw_intr_mask, intr_mask);
+
+	spin_unlock(&arbiter_lock);
+	return 0;
+}
+
+extern void show_registers(struct pt_regs *regs);
+
+static irqreturn_t crisv32_arbiter_irq(int irq, void *dev_id)
+{
+	reg_marb_r_masked_intr masked_intr =
+	    REG_RD(marb, regi_marb, r_masked_intr);
+	reg_marb_bp_r_brk_clients r_clients;
+	reg_marb_bp_r_brk_addr r_addr;
+	reg_marb_bp_r_brk_op r_op;
+	reg_marb_bp_r_brk_first_client r_first;
+	reg_marb_bp_r_brk_size r_size;
+	reg_marb_bp_rw_ack ack = { 0 };
+	reg_marb_rw_ack_intr ack_intr = {
+		.bp0 = 1, .bp1 = 1, .bp2 = 1, .bp3 = 1
+	};
+	struct crisv32_watch_entry *watch;
+
+	if (masked_intr.bp0) {
+		watch = &watches[0];
+		ack_intr.bp0 = regk_marb_yes;
+	} else if (masked_intr.bp1) {
+		watch = &watches[1];
+		ack_intr.bp1 = regk_marb_yes;
+	} else if (masked_intr.bp2) {
+		watch = &watches[2];
+		ack_intr.bp2 = regk_marb_yes;
+	} else if (masked_intr.bp3) {
+		watch = &watches[3];
+		ack_intr.bp3 = regk_marb_yes;
+	} else {
+		return IRQ_NONE;
+	}
+
+	/* Retrieve all useful information and print it. */
+	r_clients = REG_RD(marb_bp, watch->instance, r_brk_clients);
+	r_addr = REG_RD(marb_bp, watch->instance, r_brk_addr);
+	r_op = REG_RD(marb_bp, watch->instance, r_brk_op);
+	r_first = REG_RD(marb_bp, watch->instance, r_brk_first_client);
+	r_size = REG_RD(marb_bp, watch->instance, r_brk_size);
+
+	printk(KERN_INFO "Arbiter IRQ\n");
+	printk(KERN_INFO "Clients %X addr %X op %X first %X size %X\n",
+	       REG_TYPE_CONV(int, reg_marb_bp_r_brk_clients, r_clients),
+	       REG_TYPE_CONV(int, reg_marb_bp_r_brk_addr, r_addr),
+	       REG_TYPE_CONV(int, reg_marb_bp_r_brk_op, r_op),
+	       REG_TYPE_CONV(int, reg_marb_bp_r_brk_first_client, r_first),
+	       REG_TYPE_CONV(int, reg_marb_bp_r_brk_size, r_size));
+
+	REG_WR(marb_bp, watch->instance, rw_ack, ack);
+	REG_WR(marb, regi_marb, rw_ack_intr, ack_intr);
+
+	printk(KERN_INFO "IRQ occured at %lX\n", get_irq_regs()->erp);
+
+	if (watch->cb)
+		watch->cb();
+
+	return IRQ_HANDLED;
+}