diff options
Diffstat (limited to 'drivers/misc/imx_otp.c')
| -rw-r--r-- | drivers/misc/imx_otp.c | 256 |
1 files changed, 256 insertions, 0 deletions
diff --git a/drivers/misc/imx_otp.c b/drivers/misc/imx_otp.c new file mode 100644 index 0000000..917924d --- /dev/null +++ b/drivers/misc/imx_otp.c @@ -0,0 +1,256 @@ +/* + * Copyright (C) 2010-2011 Freescale Semiconductor, Inc. + * + * 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 <linux/types.h> +#include <asm/io.h> +#include <common.h> +#include <asm-arm/arch/regs-ocotp.h> +#include <imx_otp.h> + +#define HW_OCOTP_CUSTn(n) (0x00000400 + (n) * 0x10) +#define BF(value, field) (((value) << BP_##field) & BM_##field) +#define DEF_RELAX 20 + +#ifdef CONFIG_IMX_OTP_DEBUG +#define log(a, ...) printf("[%s,%3d]:"a"\n", __func__, __LINE__, ## __VA_ARGS__) +#else +#define log(a, ...) +#endif + +static int otp_wait_busy(u32 flags) +{ + int count; + u32 c; + + for (count = 10000; count >= 0; count--) { + c = readl(IMX_OTP_BASE + HW_OCOTP_CTRL); + if (!(c & (BM_OCOTP_CTRL_BUSY | BM_OCOTP_CTRL_ERROR | flags))) + break; + } + + if (count < 0) { + printf("ERROR: otp_wait_busy timeout. 0x%X\n", c); + /* clear ERROR bit, busy bit will be cleared by controller */ + writel(BM_OCOTP_CTRL_ERROR, IMX_OTP_BASE + HW_OCOTP_CTRL_CLR); + return -1; + } + + log("wait busy successful."); + return 0; +} + +static int set_otp_timing(void) +{ + u32 clk_rate = 0; + u32 relax, strobe_read, strobe_prog; + u32 timing = 0; + + /* get clock */ + clk_rate = mxc_get_clock(MXC_IPG_CLK); + if (clk_rate == -1) { + printf("ERROR: mxc_get_clock failed\n"); + return -1; + } + + log("clk_rate: %d.", clk_rate); + + relax = clk_rate / (1000000000 / DEF_RELAX) - 1; + strobe_prog = clk_rate / (1000000000 / 10000) + 2 * (DEF_RELAX + 1) - 1; + strobe_read = clk_rate / (1000000000 / 40) + 2 * (DEF_RELAX + 1) - 1; + + timing = BF(relax, OCOTP_TIMING_RELAX); + timing |= BF(strobe_read, OCOTP_TIMING_STROBE_READ); + timing |= BF(strobe_prog, OCOTP_TIMING_STROBE_PROG); + log("timing: 0x%X", timing); + + writel(timing, IMX_OTP_BASE + HW_OCOTP_TIMING); + + return 0; +} + +static int otp_read_prep(void) +{ + return (!set_otp_timing()) ? otp_wait_busy(0) : -1; +} + +static int otp_read_post(void) +{ + return 0; +} + +static int otp_blow_prep(void) +{ + return (!set_otp_timing()) ? otp_wait_busy(0) : -1; +} + +static int otp_blow_post(void) +{ + printf("Reloading shadow registers...\n"); + /* reload all the shadow registers */ + writel(BM_OCOTP_CTRL_RELOAD_SHADOWS, + IMX_OTP_BASE + HW_OCOTP_CTRL_SET); + udelay(1); + + return otp_wait_busy(BM_OCOTP_CTRL_RELOAD_SHADOWS); +} + +static int fuse_read_addr(u32 addr, u32 *pdata) +{ + u32 ctrl_reg = 0; + +#ifdef CONFIG_IMX_OTP_READ_SHADOW_REG + *pdata = readl(IMX_OTP_BASE + HW_OCOTP_CUSTn(addr)); + printf("Shadow register data: 0x%X\n", *pdata); +#endif + + ctrl_reg = readl(IMX_OTP_BASE + HW_OCOTP_CTRL); + ctrl_reg &= ~BM_OCOTP_CTRL_ADDR; + ctrl_reg &= ~BM_OCOTP_CTRL_WR_UNLOCK; + ctrl_reg |= BF(addr, OCOTP_CTRL_ADDR); + writel(ctrl_reg, IMX_OTP_BASE + HW_OCOTP_CTRL); + + writel(BM_OCOTP_READ_CTRL_READ_FUSE, IMX_OTP_BASE + HW_OCOTP_READ_CTRL); + if (otp_wait_busy(0)) + return -1; + + *pdata = readl(IMX_OTP_BASE + HW_OCOTP_READ_FUSE_DATA); + *pdata = BF_OCOTP_READ_FUSE_DATA_DATA(*pdata); + return 0; +} + +static int fuse_blow_addr(u32 addr, u32 value) +{ + u32 ctrl_reg = 0; + + log("blowing..."); + + /* control register */ + ctrl_reg = readl(IMX_OTP_BASE + HW_OCOTP_CTRL); + ctrl_reg &= ~BM_OCOTP_CTRL_ADDR; + ctrl_reg |= BF(addr, OCOTP_CTRL_ADDR); + ctrl_reg |= BF(BV_OCOTP_CTRL_WR_UNLOCK__KEY, OCOTP_CTRL_WR_UNLOCK); + writel(ctrl_reg, IMX_OTP_BASE + HW_OCOTP_CTRL); + + writel(BF_OCOTP_DATA_DATA(value), IMX_OTP_BASE + HW_OCOTP_DATA); + if (otp_wait_busy(0)) + return -1; + + /* write postamble */ + udelay(2000); + return 0; +} + +/* + * read one u32 to indexed fuse + */ +int imx_otp_read_one_u32(u32 index, u32 *pdata) +{ + u32 ctrl_reg = 0; + int ret = 0; + + log("index: 0x%X", index); + if (index > IMX_OTP_ADDR_MAX) { + printf("ERROR: invalid address.\n"); + ret = -1; + goto exit_nop; + } + + if (otp_clk_enable()) { + ret = -1; + printf("ERROR: failed to initialize OTP\n"); + goto exit_nop; + } + + if (otp_read_prep()) { + ret = -1; + printf("ERROR: read preparation failed\n"); + goto exit_cleanup; + } + if (fuse_read_addr(index, pdata)) { + ret = -1; + printf("ERROR: read failed\n"); + goto exit_cleanup; + } + if (otp_read_post()) { + ret = -1; + printf("ERROR: read post operation failed\n"); + goto exit_cleanup; + } + + if (*pdata == IMX_OTP_DATA_ERROR_VAL) { + ctrl_reg = readl(IMX_OTP_BASE + HW_OCOTP_CTRL); + if (ctrl_reg & BM_OCOTP_CTRL_ERROR) { + printf("ERROR: read fuse failed\n"); + ret = -1; + goto exit_cleanup; + } + } + +exit_cleanup: + otp_clk_disable(); +exit_nop: + return ret; +} + +/* + * blow one u32 to indexed fuse + */ +int imx_otp_blow_one_u32(u32 index, u32 data, u32 *pfused_value) +{ + u32 ctrl_reg = 0; + int ret = 0; + + if (otp_clk_enable()) { + ret = -1; + goto exit_nop; + } + + if (otp_blow_prep()) { + ret = -1; + printf("ERROR: blow preparation failed\n"); + goto exit_cleanup; + } + if (fuse_blow_addr(index, data)) { + ret = -1; + printf("ERROR: blow fuse failed\n"); + goto exit_cleanup; + } + if (otp_blow_post()) { + ret = -1; + printf("ERROR: blow post operation failed\n"); + goto exit_cleanup; + } + + ctrl_reg = readl(IMX_OTP_BASE + HW_OCOTP_CTRL); + if (ctrl_reg & BM_OCOTP_CTRL_ERROR) { + ret = -1; + goto exit_cleanup; + } + + if (imx_otp_read_one_u32(index, pfused_value)) { + ret = -1; + goto exit_cleanup; + } + +exit_cleanup: + otp_clk_disable(); +exit_nop: + return ret; +} + |