1// SPDX-License-Identifier: GPL-2.0-only
 2/*
 3 *  External Memory Interface
 4 *
 5 *  Copyright (C) 2011 Texas Instruments Incorporated
 6 *  Author: Mark Salter <msalter@redhat.com>
 7 */
 8#include <linux/of.h>
 9#include <linux/of_address.h>
10#include <linux/io.h>
11#include <asm/soc.h>
12#include <asm/dscr.h>
13
14#define NUM_EMIFA_CHIP_ENABLES 4
15
16struct emifa_regs {
17	u32	midr;
18	u32	stat;
19	u32	reserved1[6];
20	u32	bprio;
21	u32	reserved2[23];
22	u32	cecfg[NUM_EMIFA_CHIP_ENABLES];
23	u32	reserved3[4];
24	u32	awcc;
25	u32	reserved4[7];
26	u32	intraw;
27	u32	intmsk;
28	u32	intmskset;
29	u32	intmskclr;
30};
31
32static struct of_device_id emifa_match[] __initdata = {
33	{ .compatible = "ti,c64x+emifa"	},
34	{}
35};
36
37/*
38 * Parse device tree for existence of an EMIF (External Memory Interface)
39 * and initialize it if found.
40 */
41static int __init c6x_emifa_init(void)
42{
43	struct emifa_regs __iomem *regs;
44	struct device_node *node;
45	const __be32 *p;
46	u32 val;
47	int i, len, err;
48
49	node = of_find_matching_node(NULL, emifa_match);
50	if (!node)
51		return 0;
52
53	regs = of_iomap(node, 0);
54	if (!regs)
55		return 0;
56
57	/* look for a dscr-based enable for emifa pin buffers */
58	err = of_property_read_u32_array(node, "ti,dscr-dev-enable", &val, 1);
59	if (!err)
60		dscr_set_devstate(val, DSCR_DEVSTATE_ENABLED);
61
62	/* set up the chip enables */
63	p = of_get_property(node, "ti,emifa-ce-config", &len);
64	if (p) {
65		len /= sizeof(u32);
66		if (len > NUM_EMIFA_CHIP_ENABLES)
67			len = NUM_EMIFA_CHIP_ENABLES;
68		for (i = 0; i <= len; i++)
69			soc_writel(be32_to_cpup(&p[i]), &regs->cecfg[i]);
70	}
71
72	err = of_property_read_u32_array(node, "ti,emifa-burst-priority", &val, 1);
73	if (!err)
74		soc_writel(val, &regs->bprio);
75
76	err = of_property_read_u32_array(node, "ti,emifa-async-wait-control", &val, 1);
77	if (!err)
78		soc_writel(val, &regs->awcc);
79
80	iounmap(regs);
81	of_node_put(node);
82	return 0;
83}
84pure_initcall(c6x_emifa_init);