3 * Texas Instruments, <www.ti.com>
6 * Tom Rini <trini@ti.com>
9 * Richard Woodruff <r-woodruff2@ti.com>
10 * Jian Zhang <jzhang@ti.com>
12 * SPDX-License-Identifier: GPL-2.0+
16 #include <linux/mtd/nand.h>
18 #include <asm/arch/sys_proto.h>
19 #include <asm/arch/mem.h>
21 static struct gpmc *gpmc_config = (struct gpmc *)GPMC_BASE;
23 /* nand_command: Send a flash command to the flash chip */
24 static void nand_command(u8 command)
26 writeb(command, &gpmc_config->cs[0].nand_cmd);
28 if (command == NAND_CMD_RESET) {
29 unsigned char ret_val;
30 writeb(NAND_CMD_STATUS, &gpmc_config->cs[0].nand_cmd);
32 /* Wait until ready */
33 ret_val = readl(&gpmc_config->cs[0].nand_dat);
34 } while ((ret_val & NAND_STATUS_READY) != NAND_STATUS_READY);
39 * Many boards will want to know the results of the NAND_CMD_READID command
40 * in order to decide what to do about DDR initialization. This function
41 * allows us to do that very early and to pass those results back to the
42 * board so it can make whatever decisions need to be made.
44 void identify_nand_chip(int *mfr, int *id)
46 /* Make sure that we have setup GPMC for NAND correctly. */
47 writel(M_NAND_GPMC_CONFIG1, &gpmc_config->cs[0].config1);
48 writel(M_NAND_GPMC_CONFIG2, &gpmc_config->cs[0].config2);
49 writel(M_NAND_GPMC_CONFIG3, &gpmc_config->cs[0].config3);
50 writel(M_NAND_GPMC_CONFIG4, &gpmc_config->cs[0].config4);
51 writel(M_NAND_GPMC_CONFIG5, &gpmc_config->cs[0].config5);
52 writel(M_NAND_GPMC_CONFIG6, &gpmc_config->cs[0].config6);
55 * Enable the config. The CS size goes in bits 11:8. We set
56 * bit 6 to enable the CS and the base address goes into bits 5:0.
58 writel((GPMC_SIZE_128M << 8) | (GPMC_CS_ENABLE << 6) |
59 ((NAND_BASE >> 24) & GPMC_BASEADDR_MASK),
60 &gpmc_config->cs[0].config7);
64 /* Issue a RESET and then READID */
65 nand_command(NAND_CMD_RESET);
66 nand_command(NAND_CMD_READID);
68 /* Set the address to read to 0x0 */
69 writeb(0x0, &gpmc_config->cs[0].nand_adr);
71 /* Read off the manufacturer and device id. */
72 *mfr = readb(&gpmc_config->cs[0].nand_dat);
73 *id = readb(&gpmc_config->cs[0].nand_dat);