diff options
Diffstat (limited to 'drivers/misc/mxc_ocotp.c')
| -rw-r--r-- | drivers/misc/mxc_ocotp.c | 216 |
1 files changed, 216 insertions, 0 deletions
diff --git a/drivers/misc/mxc_ocotp.c b/drivers/misc/mxc_ocotp.c new file mode 100644 index 0000000..0095b47 --- /dev/null +++ b/drivers/misc/mxc_ocotp.c @@ -0,0 +1,216 @@ +/* + * (C) Copyright 2013 ADVANSEE + * Benoît Thébaudeau <benoit.thebaudeau@advansee.com> + * + * Based on Dirk Behme's + * https://github.com/dirkbehme/u-boot-imx6/blob/28b17e9/drivers/misc/imx_otp.c, + * which is based on Freescale's + * http://git.freescale.com/git/cgit.cgi/imx/uboot-imx.git/tree/drivers/misc/imx_otp.c?h=imx_v2009.08_1.1.0&id=9aa74e6, + * which is: + * Copyright (C) 2011 Freescale Semiconductor, Inc. + * + * See file CREDITS for list of people who contributed to this + * project. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + */ + +#include <common.h> +#include <fuse.h> +#include <asm/errno.h> +#include <asm/io.h> +#include <asm/arch/clock.h> +#include <asm/arch/imx-regs.h> + +#define BO_CTRL_WR_UNLOCK 16 +#define BM_CTRL_WR_UNLOCK 0xffff0000 +#define BV_CTRL_WR_UNLOCK_KEY 0x3e77 +#define BM_CTRL_ERROR 0x00000200 +#define BM_CTRL_BUSY 0x00000100 +#define BO_CTRL_ADDR 0 +#define BM_CTRL_ADDR 0x0000007f + +#define BO_TIMING_STROBE_READ 16 +#define BM_TIMING_STROBE_READ 0x003f0000 +#define BV_TIMING_STROBE_READ_NS 37 +#define BO_TIMING_RELAX 12 +#define BM_TIMING_RELAX 0x0000f000 +#define BV_TIMING_RELAX_NS 17 +#define BO_TIMING_STROBE_PROG 0 +#define BM_TIMING_STROBE_PROG 0x00000fff +#define BV_TIMING_STROBE_PROG_US 10 + +#define BM_READ_CTRL_READ_FUSE 0x00000001 + +#define BF(value, field) (((value) << BO_##field) & BM_##field) + +#define WRITE_POSTAMBLE_US 2 + +static void wait_busy(struct ocotp_regs *regs, unsigned int delay_us) +{ + while (readl(®s->ctrl) & BM_CTRL_BUSY) + udelay(delay_us); +} + +static void clear_error(struct ocotp_regs *regs) +{ + writel(BM_CTRL_ERROR, ®s->ctrl_clr); +} + +static int prepare_access(struct ocotp_regs **regs, u32 bank, u32 word, + int assert, const char *caller) +{ + *regs = (struct ocotp_regs *)OCOTP_BASE_ADDR; + + if (bank >= ARRAY_SIZE((*regs)->bank) || + word >= ARRAY_SIZE((*regs)->bank[0].fuse_regs) >> 2 || + !assert) { + printf("mxc_ocotp %s(): Invalid argument\n", caller); + return -EINVAL; + } + + enable_ocotp_clk(1); + + wait_busy(*regs, 1); + clear_error(*regs); + + return 0; +} + +static int finish_access(struct ocotp_regs *regs, const char *caller) +{ + u32 err; + + err = !!(readl(®s->ctrl) & BM_CTRL_ERROR); + clear_error(regs); + + enable_ocotp_clk(0); + + if (err) { + printf("mxc_ocotp %s(): Access protect error\n", caller); + return -EIO; + } + + return 0; +} + +static int prepare_read(struct ocotp_regs **regs, u32 bank, u32 word, u32 *val, + const char *caller) +{ + return prepare_access(regs, bank, word, val != NULL, caller); +} + +int fuse_read(u32 bank, u32 word, u32 *val) +{ + struct ocotp_regs *regs; + int ret; + + ret = prepare_read(®s, bank, word, val, __func__); + if (ret) + return ret; + + *val = readl(®s->bank[bank].fuse_regs[word << 2]); + + return finish_access(regs, __func__); +} + +static void set_timing(struct ocotp_regs *regs) +{ + u32 ipg_clk; + u32 relax, strobe_read, strobe_prog; + u32 timing; + + ipg_clk = mxc_get_clock(MXC_IPG_CLK); + + relax = DIV_ROUND_UP(ipg_clk * BV_TIMING_RELAX_NS, 1000000000) - 1; + strobe_read = DIV_ROUND_UP(ipg_clk * BV_TIMING_STROBE_READ_NS, + 1000000000) + 2 * (relax + 1) - 1; + strobe_prog = DIV_ROUND(ipg_clk * BV_TIMING_STROBE_PROG_US, 1000000) + + 2 * (relax + 1) - 1; + + timing = BF(strobe_read, TIMING_STROBE_READ) | + BF(relax, TIMING_RELAX) | + BF(strobe_prog, TIMING_STROBE_PROG); + + clrsetbits_le32(®s->timing, BM_TIMING_STROBE_READ | BM_TIMING_RELAX | + BM_TIMING_STROBE_PROG, timing); +} + +static void setup_direct_access(struct ocotp_regs *regs, u32 bank, u32 word, + int write) +{ + u32 wr_unlock = write ? BV_CTRL_WR_UNLOCK_KEY : 0; + u32 addr = bank << 3 | word; + + set_timing(regs); + clrsetbits_le32(®s->ctrl, BM_CTRL_WR_UNLOCK | BM_CTRL_ADDR, + BF(wr_unlock, CTRL_WR_UNLOCK) | + BF(addr, CTRL_ADDR)); +} + +int fuse_sense(u32 bank, u32 word, u32 *val) +{ + struct ocotp_regs *regs; + int ret; + + ret = prepare_read(®s, bank, word, val, __func__); + if (ret) + return ret; + + setup_direct_access(regs, bank, word, false); + writel(BM_READ_CTRL_READ_FUSE, ®s->read_ctrl); + wait_busy(regs, 1); + *val = readl(®s->read_fuse_data); + + return finish_access(regs, __func__); +} + +static int prepare_write(struct ocotp_regs **regs, u32 bank, u32 word, + const char *caller) +{ + return prepare_access(regs, bank, word, true, caller); +} + +int fuse_prog(u32 bank, u32 word, u32 val) +{ + struct ocotp_regs *regs; + int ret; + + ret = prepare_write(®s, bank, word, __func__); + if (ret) + return ret; + + setup_direct_access(regs, bank, word, true); + writel(val, ®s->data); + wait_busy(regs, BV_TIMING_STROBE_PROG_US); + udelay(WRITE_POSTAMBLE_US); + + return finish_access(regs, __func__); +} + +int fuse_override(u32 bank, u32 word, u32 val) +{ + struct ocotp_regs *regs; + int ret; + + ret = prepare_write(®s, bank, word, __func__); + if (ret) + return ret; + + writel(val, ®s->bank[bank].fuse_regs[word << 2]); + + return finish_access(regs, __func__); +} |