[POWERPC] bestcomm: core bestcomm support for Freescale MPC5200

This patch adds support for the core of the BestComm API
for the Freescale MPC5200(b). The BestComm engine is a
microcode-controlled / tasks-based DMA used by several
of the onchip devices.

Setting up the tasks / memory allocation and all common
low level functions are handled by this patch.
The specifics details of each tasks and their microcode
are split-out in separate patches.

This is not the official API, but a much cleaner one.
(hopefully)

Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

1 files changed, 528 insertions, 0 deletions

diff --git a/arch/powerpc/sysdev/bestcomm/bestcomm.c b/arch/powerpc/sysdev/bestcomm/bestcomm.c
new file mode 100644
index 000000000000..48492a83e5a7
--- /dev/null
+++ b/arch/powerpc/sysdev/bestcomm/bestcomm.c
@@ -0,0 +1,528 @@
+/*
+ * Driver for MPC52xx processor BestComm peripheral controller
+ *
+ *
+ * Copyright (C) 2006-2007 Sylvain Munaut <tnt@246tNt.com>
+ * Copyright (C) 2005      Varma Electronics Oy,
+ *                         ( by Andrey Volkov <avolkov@varma-el.com> )
+ * Copyright (C) 2003-2004 MontaVista, Software, Inc.
+ *                         ( by Dale Farnsworth <dfarnsworth@mvista.com> )
+ *
+ * This file is licensed under the terms of the GNU General Public License
+ * version 2. This program is licensed "as is" without any warranty of any
+ * kind, whether express or implied.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_platform.h>
+#include <asm/io.h>
+#include <asm/irq.h>
+#include <asm/mpc52xx.h>
+
+#include "sram.h"
+#include "bestcomm_priv.h"
+#include "bestcomm.h"
+
+#define DRIVER_NAME "bestcomm-core"
+
+
+struct bcom_engine *bcom_eng = NULL;
+EXPORT_SYMBOL_GPL(bcom_eng);	/* needed for inline functions */
+
+
+/* ======================================================================== */
+/* Public and private API                                                   */
+/* ======================================================================== */
+
+/* Private API */
+
+struct bcom_task *
+bcom_task_alloc(int bd_count, int bd_size, int priv_size)
+{
+	int i, tasknum = -1;
+	struct bcom_task *tsk;
+
+	/* Get and reserve a task num */
+	spin_lock(&bcom_eng->lock);
+
+	for (i=0; i<BCOM_MAX_TASKS; i++)
+		if (!bcom_eng->tdt[i].stop) {	/* we use stop as a marker */
+			bcom_eng->tdt[i].stop = 0xfffffffful; /* dummy addr */
+			tasknum = i;
+			break;
+		}
+
+	spin_unlock(&bcom_eng->lock);
+
+	if (tasknum < 0)
+		return NULL;
+
+	/* Allocate our structure */
+	tsk = kzalloc(sizeof(struct bcom_task) + priv_size, GFP_KERNEL);
+	if (!tsk)
+		goto error;
+
+	tsk->tasknum = tasknum;
+	if (priv_size)
+		tsk->priv = (void*)tsk + sizeof(struct bcom_task);
+
+	/* Get IRQ of that task */
+	tsk->irq = irq_of_parse_and_map(bcom_eng->ofnode, tsk->tasknum);
+	if (tsk->irq == NO_IRQ)
+		goto error;
+
+	/* Init the BDs, if needed */
+	if (bd_count) {
+		tsk->cookie = kmalloc(sizeof(void*) * bd_count, GFP_KERNEL);
+		if (!tsk->cookie)
+			goto error;
+
+		tsk->bd = bcom_sram_alloc(bd_count * bd_size, 4, &tsk->bd_pa);
+		if (!tsk->bd)
+			goto error;
+		memset(tsk->bd, 0x00, bd_count * bd_size);
+
+		tsk->num_bd = bd_count;
+		tsk->bd_size = bd_size;
+	}
+
+	return tsk;
+
+error:
+	if (tsk) {
+		if (tsk->irq != NO_IRQ)
+			irq_dispose_mapping(tsk->irq);
+		bcom_sram_free(tsk->bd);
+		kfree(tsk->cookie);
+		kfree(tsk);
+	}
+
+	bcom_eng->tdt[tasknum].stop = 0;
+
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(bcom_task_alloc);
+
+void
+bcom_task_free(struct bcom_task *tsk)
+{
+	/* Stop the task */
+	bcom_disable_task(tsk->tasknum);
+
+	/* Clear TDT */
+	bcom_eng->tdt[tsk->tasknum].start = 0;
+	bcom_eng->tdt[tsk->tasknum].stop  = 0;
+
+	/* Free everything */
+	irq_dispose_mapping(tsk->irq);
+	bcom_sram_free(tsk->bd);
+	kfree(tsk->cookie);
+	kfree(tsk);
+}
+EXPORT_SYMBOL_GPL(bcom_task_free);
+
+int
+bcom_load_image(int task, u32 *task_image)
+{
+	struct bcom_task_header *hdr = (struct bcom_task_header *)task_image;
+	struct bcom_tdt *tdt;
+	u32 *desc, *var, *inc;
+	u32 *desc_src, *var_src, *inc_src;
+
+	/* Safety checks */
+	if (hdr->magic != BCOM_TASK_MAGIC) {
+		printk(KERN_ERR DRIVER_NAME
+			": Trying to load invalid microcode\n");
+		return -EINVAL;
+	}
+
+	if ((task < 0) || (task >= BCOM_MAX_TASKS)) {
+		printk(KERN_ERR DRIVER_NAME
+			": Trying to load invalid task %d\n", task);
+		return -EINVAL;
+	}
+
+	/* Initial load or reload */
+	tdt = &bcom_eng->tdt[task];
+
+	if (tdt->start) {
+		desc = bcom_task_desc(task);
+		if (hdr->desc_size != bcom_task_num_descs(task)) {
+			printk(KERN_ERR DRIVER_NAME
+				": Trying to reload wrong task image "
+				"(%d size %d/%d)!\n",
+				task,
+				hdr->desc_size,
+				bcom_task_num_descs(task));
+			return -EINVAL;
+		}
+	} else {
+		phys_addr_t start_pa;
+
+		desc = bcom_sram_alloc(hdr->desc_size * sizeof(u32), 4, &start_pa);
+		if (!desc)
+			return -ENOMEM;
+
+		tdt->start = start_pa;
+		tdt->stop = start_pa + ((hdr->desc_size-1) * sizeof(u32));
+	}
+
+	var = bcom_task_var(task);
+	inc = bcom_task_inc(task);
+
+	/* Clear & copy */
+	memset(var, 0x00, BCOM_VAR_SIZE);
+	memset(inc, 0x00, BCOM_INC_SIZE);
+
+	desc_src = (u32 *)(hdr + 1);
+	var_src = desc_src + hdr->desc_size;
+	inc_src = var_src + hdr->var_size;
+
+	memcpy(desc, desc_src, hdr->desc_size * sizeof(u32));
+	memcpy(var + hdr->first_var, var_src, hdr->var_size * sizeof(u32));
+	memcpy(inc, inc_src, hdr->inc_size * sizeof(u32));
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(bcom_load_image);
+
+void
+bcom_set_initiator(int task, int initiator)
+{
+	int i;
+	int num_descs;
+	u32 *desc;
+	int next_drd_has_initiator;
+
+	bcom_set_tcr_initiator(task, initiator);
+
+	/* Just setting tcr is apparently not enough due to some problem */
+	/* with it. So we just go thru all the microcode and replace in  */
+	/* the DRD directly */
+
+	desc = bcom_task_desc(task);
+	next_drd_has_initiator = 1;
+	num_descs = bcom_task_num_descs(task);
+
+	for (i=0; i<num_descs; i++, desc++) {
+		if (!bcom_desc_is_drd(*desc))
+			continue;
+		if (next_drd_has_initiator)
+			if (bcom_desc_initiator(*desc) != BCOM_INITIATOR_ALWAYS)
+				bcom_set_desc_initiator(desc, initiator);
+		next_drd_has_initiator = !bcom_drd_is_extended(*desc);
+	}
+}
+EXPORT_SYMBOL_GPL(bcom_set_initiator);
+
+
+/* Public API */
+
+void
+bcom_enable(struct bcom_task *tsk)
+{
+	bcom_enable_task(tsk->tasknum);
+}
+EXPORT_SYMBOL_GPL(bcom_enable);
+
+void
+bcom_disable(struct bcom_task *tsk)
+{
+	bcom_disable_task(tsk->tasknum);
+}
+EXPORT_SYMBOL_GPL(bcom_disable);
+
+
+/* ======================================================================== */
+/* Engine init/cleanup                                                      */
+/* ======================================================================== */
+
+/* Function Descriptor table */
+/* this will need to be updated if Freescale changes their task code FDT */
+static u32 fdt_ops[] = {
+	0xa0045670,	/* FDT[48] - load_acc()	  */
+	0x80045670,	/* FDT[49] - unload_acc() */
+	0x21800000,	/* FDT[50] - and()        */
+	0x21e00000,	/* FDT[51] - or()         */
+	0x21500000,	/* FDT[52] - xor()        */
+	0x21400000,	/* FDT[53] - andn()       */
+	0x21500000,	/* FDT[54] - not()        */
+	0x20400000,	/* FDT[55] - add()        */
+	0x20500000,	/* FDT[56] - sub()        */
+	0x20800000,	/* FDT[57] - lsh()        */
+	0x20a00000,	/* FDT[58] - rsh()        */
+	0xc0170000,	/* FDT[59] - crc8()       */
+	0xc0145670,	/* FDT[60] - crc16()      */
+	0xc0345670,	/* FDT[61] - crc32()      */
+	0xa0076540,	/* FDT[62] - endian32()   */
+	0xa0000760,	/* FDT[63] - endian16()   */
+};
+
+
+static int __devinit
+bcom_engine_init(void)
+{
+	int task;
+	phys_addr_t tdt_pa, ctx_pa, var_pa, fdt_pa;
+	unsigned int tdt_size, ctx_size, var_size, fdt_size;
+
+	/* Allocate & clear SRAM zones for FDT, TDTs, contexts and vars/incs */
+	tdt_size = BCOM_MAX_TASKS * sizeof(struct bcom_tdt);
+	ctx_size = BCOM_MAX_TASKS * BCOM_CTX_SIZE;
+	var_size = BCOM_MAX_TASKS * (BCOM_VAR_SIZE + BCOM_INC_SIZE);
+	fdt_size = BCOM_FDT_SIZE;
+
+	bcom_eng->tdt = bcom_sram_alloc(tdt_size, sizeof(u32), &tdt_pa);
+	bcom_eng->ctx = bcom_sram_alloc(ctx_size, BCOM_CTX_ALIGN, &ctx_pa);
+	bcom_eng->var = bcom_sram_alloc(var_size, BCOM_VAR_ALIGN, &var_pa);
+	bcom_eng->fdt = bcom_sram_alloc(fdt_size, BCOM_FDT_ALIGN, &fdt_pa);
+
+	if (!bcom_eng->tdt || !bcom_eng->ctx || !bcom_eng->var || !bcom_eng->fdt) {
+		printk(KERN_ERR "DMA: SRAM alloc failed in engine init !\n");
+
+		bcom_sram_free(bcom_eng->tdt);
+		bcom_sram_free(bcom_eng->ctx);
+		bcom_sram_free(bcom_eng->var);
+		bcom_sram_free(bcom_eng->fdt);
+
+		return -ENOMEM;
+	}
+
+	memset(bcom_eng->tdt, 0x00, tdt_size);
+	memset(bcom_eng->ctx, 0x00, ctx_size);
+	memset(bcom_eng->var, 0x00, var_size);
+	memset(bcom_eng->fdt, 0x00, fdt_size);
+
+	/* Copy the FDT for the EU#3 */
+	memcpy(&bcom_eng->fdt[48], fdt_ops, sizeof(fdt_ops));
+
+	/* Initialize Task base structure */
+	for (task=0; task<BCOM_MAX_TASKS; task++)
+	{
+		out_be16(&bcom_eng->regs->tcr[task], 0);
+		out_8(&bcom_eng->regs->ipr[task], 0);
+
+		bcom_eng->tdt[task].context	= ctx_pa;
+		bcom_eng->tdt[task].var	= var_pa;
+		bcom_eng->tdt[task].fdt	= fdt_pa;
+
+		var_pa += BCOM_VAR_SIZE + BCOM_INC_SIZE;
+		ctx_pa += BCOM_CTX_SIZE;
+	}
+
+	out_be32(&bcom_eng->regs->taskBar, tdt_pa);
+
+	/* Init 'always' initiator */
+	out_8(&bcom_eng->regs->ipr[BCOM_INITIATOR_ALWAYS], BCOM_IPR_ALWAYS);
+
+	/* Disable COMM Bus Prefetch, apparently it's not reliable yet */
+	/* FIXME: This should be done on 5200 and not 5200B ... */
+	out_be16(&bcom_eng->regs->PtdCntrl, in_be16(&bcom_eng->regs->PtdCntrl) | 1);
+
+	/* Init lock */
+	spin_lock_init(&bcom_eng->lock);
+
+	return 0;
+}
+
+static void
+bcom_engine_cleanup(void)
+{
+	int task;
+
+	/* Stop all tasks */
+	for (task=0; task<BCOM_MAX_TASKS; task++)
+	{
+		out_be16(&bcom_eng->regs->tcr[task], 0);
+		out_8(&bcom_eng->regs->ipr[task], 0);
+	}
+
+	out_be32(&bcom_eng->regs->taskBar, 0ul);
+
+	/* Release the SRAM zones */
+	bcom_sram_free(bcom_eng->tdt);
+	bcom_sram_free(bcom_eng->ctx);
+	bcom_sram_free(bcom_eng->var);
+	bcom_sram_free(bcom_eng->fdt);
+}
+
+
+/* ======================================================================== */
+/* OF platform driver                                                       */
+/* ======================================================================== */
+
+static int __devinit
+mpc52xx_bcom_probe(struct of_device *op, const struct of_device_id *match)
+{
+	struct device_node *ofn_sram;
+	struct resource res_bcom;
+
+	int rv;
+
+	/* Inform user we're ok so far */
+	printk(KERN_INFO "DMA: MPC52xx BestComm driver\n");
+
+	/* Get the bestcomm node */
+	of_node_get(op->node);
+
+	/* Prepare SRAM */
+	ofn_sram = of_find_compatible_node(NULL, "sram", "mpc5200-sram");
+	if (!ofn_sram) {
+		printk(KERN_ERR DRIVER_NAME ": "
+			"No SRAM found in device tree\n");
+		rv = -ENODEV;
+		goto error_ofput;
+	}
+	rv = bcom_sram_init(ofn_sram, DRIVER_NAME);
+	of_node_put(ofn_sram);
+
+	if (rv) {
+		printk(KERN_ERR DRIVER_NAME ": "
+			"Error in SRAM init\n");
+		goto error_ofput;
+	}
+
+	/* Get a clean struct */
+	bcom_eng = kzalloc(sizeof(struct bcom_engine), GFP_KERNEL);
+	if (!bcom_eng) {
+		printk(KERN_ERR DRIVER_NAME ": "
+			"Can't allocate state structure\n");
+		rv = -ENOMEM;
+		goto error_sramclean;
+	}
+
+	/* Save the node */
+	bcom_eng->ofnode = op->node;
+
+	/* Get, reserve & map io */
+	if (of_address_to_resource(op->node, 0, &res_bcom)) {
+		printk(KERN_ERR DRIVER_NAME ": "
+			"Can't get resource\n");
+		rv = -EINVAL;
+		goto error_sramclean;
+	}
+
+	if (!request_mem_region(res_bcom.start, sizeof(struct mpc52xx_sdma),
+				DRIVER_NAME)) {
+		printk(KERN_ERR DRIVER_NAME ": "
+			"Can't request registers region\n");
+		rv = -EBUSY;
+		goto error_sramclean;
+	}
+
+	bcom_eng->regs_base = res_bcom.start;
+	bcom_eng->regs = ioremap(res_bcom.start, sizeof(struct mpc52xx_sdma));
+	if (!bcom_eng->regs) {
+		printk(KERN_ERR DRIVER_NAME ": "
+			"Can't map registers\n");
+		rv = -ENOMEM;
+		goto error_release;
+	}
+
+	/* Now, do the real init */
+	rv = bcom_engine_init();
+	if (rv)
+		goto error_unmap;
+
+	/* Done ! */
+	printk(KERN_INFO "DMA: MPC52xx BestComm engine @%08lx ok !\n",
+		bcom_eng->regs_base);
+
+	return 0;
+
+	/* Error path */
+error_unmap:
+	iounmap(bcom_eng->regs);
+error_release:
+	release_mem_region(res_bcom.start, sizeof(struct mpc52xx_sdma));
+error_sramclean:
+	kfree(bcom_eng);
+	bcom_sram_cleanup();
+error_ofput:
+	of_node_put(op->node);
+
+	printk(KERN_ERR "DMA: MPC52xx BestComm init failed !\n");
+
+	return rv;
+}
+
+
+static int
+mpc52xx_bcom_remove(struct of_device *op)
+{
+	/* Clean up the engine */
+	bcom_engine_cleanup();
+
+	/* Cleanup SRAM */
+	bcom_sram_cleanup();
+
+	/* Release regs */
+	iounmap(bcom_eng->regs);
+	release_mem_region(bcom_eng->regs_base, sizeof(struct mpc52xx_sdma));
+
+	/* Release the node */
+	of_node_put(bcom_eng->ofnode);
+
+	/* Release memory */
+	kfree(bcom_eng);
+	bcom_eng = NULL;
+
+	return 0;
+}
+
+static struct of_device_id mpc52xx_bcom_of_match[] = {
+	{
+		.type		= "dma-controller",
+		.compatible	= "mpc5200-bestcomm",
+	},
+	{},
+};
+
+MODULE_DEVICE_TABLE(of, mpc52xx_bcom_of_match);
+
+
+static struct of_platform_driver mpc52xx_bcom_of_platform_driver = {
+	.owner		= THIS_MODULE,
+	.name		= DRIVER_NAME,
+	.match_table	= mpc52xx_bcom_of_match,
+	.probe		= mpc52xx_bcom_probe,
+	.remove		= mpc52xx_bcom_remove,
+	.driver		= {
+		.name	= DRIVER_NAME,
+		.owner	= THIS_MODULE,
+	},
+};
+
+
+/* ======================================================================== */
+/* Module                                                                   */
+/* ======================================================================== */
+
+static int __init
+mpc52xx_bcom_init(void)
+{
+	return of_register_platform_driver(&mpc52xx_bcom_of_platform_driver);
+}
+
+static void __exit
+mpc52xx_bcom_exit(void)
+{
+	of_unregister_platform_driver(&mpc52xx_bcom_of_platform_driver);
+}
+
+/* If we're not a module, we must make sure everything is setup before  */
+/* anyone tries to use us ... that's why we use subsys_initcall instead */
+/* of module_init. */
+subsys_initcall(mpc52xx_bcom_init);
+module_exit(mpc52xx_bcom_exit);
+
+MODULE_DESCRIPTION("Freescale MPC52xx BestComm DMA");
+MODULE_AUTHOR("Sylvain Munaut <tnt@246tNt.com>");
+MODULE_AUTHOR("Andrey Volkov <avolkov@varma-el.com>");
+MODULE_AUTHOR("Dale Farnsworth <dfarnsworth@mvista.com>");
+MODULE_LICENSE("GPL v2");
+