xref: /linux/drivers/bcma/driver_chipcommon_nflash.c (revision 4f2c0a4acffbec01079c28f839422e64ddeff004)
1 /*
2  * Broadcom specific AMBA
3  * ChipCommon NAND flash interface
4  *
5  * Licensed under the GNU/GPL. See COPYING for details.
6  */
7 
8 #include "bcma_private.h"
9 
10 #include <linux/bitops.h>
11 #include <linux/platform_device.h>
12 #include <linux/platform_data/brcmnand.h>
13 #include <linux/bcma/bcma.h>
14 
15 /* Alternate NAND controller driver name in order to allow both bcm47xxnflash
16  * and bcma_brcmnand to be built into the same kernel image.
17  */
18 static const char *bcma_nflash_alt_name = "bcma_brcmnand";
19 
20 struct platform_device bcma_nflash_dev = {
21 	.name		= "bcma_nflash",
22 	.num_resources	= 0,
23 };
24 
25 static const char *probes[] = { "bcm47xxpart", NULL };
26 
27 /* Initialize NAND flash access */
bcma_nflash_init(struct bcma_drv_cc * cc)28 int bcma_nflash_init(struct bcma_drv_cc *cc)
29 {
30 	struct bcma_bus *bus = cc->core->bus;
31 	u32 reg;
32 
33 	if (bus->chipinfo.id != BCMA_CHIP_ID_BCM4706 &&
34 	    cc->core->id.rev != 38) {
35 		bcma_err(bus, "NAND flash on unsupported board!\n");
36 		return -ENOTSUPP;
37 	}
38 
39 	if (!(cc->capabilities & BCMA_CC_CAP_NFLASH)) {
40 		bcma_err(bus, "NAND flash not present according to ChipCommon\n");
41 		return -ENODEV;
42 	}
43 
44 	cc->nflash.present = true;
45 	if (cc->core->id.rev == 38 &&
46 	    (cc->status & BCMA_CC_CHIPST_5357_NAND_BOOT)) {
47 		cc->nflash.boot = true;
48 		/* Determine the chip select that is being used */
49 		reg = bcma_cc_read32(cc, BCMA_CC_NAND_CS_NAND_SELECT) & 0xff;
50 		cc->nflash.brcmnand_info.chip_select = ffs(reg) - 1;
51 		cc->nflash.brcmnand_info.part_probe_types = probes;
52 		cc->nflash.brcmnand_info.ecc_stepsize = 512;
53 		cc->nflash.brcmnand_info.ecc_strength = 1;
54 		bcma_nflash_dev.name = bcma_nflash_alt_name;
55 	}
56 
57 	/* Prepare platform device, but don't register it yet. It's too early,
58 	 * malloc (required by device_private_init) is not available yet. */
59 	bcma_nflash_dev.dev.platform_data = &cc->nflash;
60 
61 	return 0;
62 }
63