diff options
Diffstat (limited to '')
-rw-r--r-- | drivers/nvmem/imx-ocotp.c | 644 |
1 files changed, 644 insertions, 0 deletions
diff --git a/drivers/nvmem/imx-ocotp.c b/drivers/nvmem/imx-ocotp.c new file mode 100644 index 000000000..9590a864e --- /dev/null +++ b/drivers/nvmem/imx-ocotp.c @@ -0,0 +1,644 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * i.MX6 OCOTP fusebox driver + * + * Copyright (c) 2015 Pengutronix, Philipp Zabel <p.zabel@pengutronix.de> + * + * Copyright 2019 NXP + * + * Based on the barebox ocotp driver, + * Copyright (c) 2010 Baruch Siach <baruch@tkos.co.il>, + * Orex Computed Radiography + * + * Write support based on the fsl_otp driver, + * Copyright (C) 2010-2013 Freescale Semiconductor, Inc + */ + +#include <linux/clk.h> +#include <linux/device.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/nvmem-provider.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/platform_device.h> +#include <linux/slab.h> +#include <linux/delay.h> + +#define IMX_OCOTP_OFFSET_B0W0 0x400 /* Offset from base address of the + * OTP Bank0 Word0 + */ +#define IMX_OCOTP_OFFSET_PER_WORD 0x10 /* Offset between the start addr + * of two consecutive OTP words. + */ + +#define IMX_OCOTP_ADDR_CTRL 0x0000 +#define IMX_OCOTP_ADDR_CTRL_SET 0x0004 +#define IMX_OCOTP_ADDR_CTRL_CLR 0x0008 +#define IMX_OCOTP_ADDR_TIMING 0x0010 +#define IMX_OCOTP_ADDR_DATA0 0x0020 +#define IMX_OCOTP_ADDR_DATA1 0x0030 +#define IMX_OCOTP_ADDR_DATA2 0x0040 +#define IMX_OCOTP_ADDR_DATA3 0x0050 + +#define IMX_OCOTP_BM_CTRL_ADDR 0x000000FF +#define IMX_OCOTP_BM_CTRL_BUSY 0x00000100 +#define IMX_OCOTP_BM_CTRL_ERROR 0x00000200 +#define IMX_OCOTP_BM_CTRL_REL_SHADOWS 0x00000400 + +#define IMX_OCOTP_BM_CTRL_ADDR_8MP 0x000001FF +#define IMX_OCOTP_BM_CTRL_BUSY_8MP 0x00000200 +#define IMX_OCOTP_BM_CTRL_ERROR_8MP 0x00000400 +#define IMX_OCOTP_BM_CTRL_REL_SHADOWS_8MP 0x00000800 + +#define IMX_OCOTP_BM_CTRL_DEFAULT \ + { \ + .bm_addr = IMX_OCOTP_BM_CTRL_ADDR, \ + .bm_busy = IMX_OCOTP_BM_CTRL_BUSY, \ + .bm_error = IMX_OCOTP_BM_CTRL_ERROR, \ + .bm_rel_shadows = IMX_OCOTP_BM_CTRL_REL_SHADOWS,\ + } + +#define IMX_OCOTP_BM_CTRL_8MP \ + { \ + .bm_addr = IMX_OCOTP_BM_CTRL_ADDR_8MP, \ + .bm_busy = IMX_OCOTP_BM_CTRL_BUSY_8MP, \ + .bm_error = IMX_OCOTP_BM_CTRL_ERROR_8MP, \ + .bm_rel_shadows = IMX_OCOTP_BM_CTRL_REL_SHADOWS_8MP,\ + } + +#define TIMING_STROBE_PROG_US 10 /* Min time to blow a fuse */ +#define TIMING_STROBE_READ_NS 37 /* Min time before read */ +#define TIMING_RELAX_NS 17 +#define DEF_FSOURCE 1001 /* > 1000 ns */ +#define DEF_STROBE_PROG 10000 /* IPG clocks */ +#define IMX_OCOTP_WR_UNLOCK 0x3E770000 +#define IMX_OCOTP_READ_LOCKED_VAL 0xBADABADA + +static DEFINE_MUTEX(ocotp_mutex); + +struct ocotp_priv { + struct device *dev; + struct clk *clk; + void __iomem *base; + const struct ocotp_params *params; + struct nvmem_config *config; +}; + +struct ocotp_ctrl_reg { + u32 bm_addr; + u32 bm_busy; + u32 bm_error; + u32 bm_rel_shadows; +}; + +struct ocotp_params { + unsigned int nregs; + unsigned int bank_address_words; + void (*set_timing)(struct ocotp_priv *priv); + struct ocotp_ctrl_reg ctrl; + bool reverse_mac_address; +}; + +static int imx_ocotp_wait_for_busy(struct ocotp_priv *priv, u32 flags) +{ + int count; + u32 c, mask; + u32 bm_ctrl_busy, bm_ctrl_error; + void __iomem *base = priv->base; + + bm_ctrl_busy = priv->params->ctrl.bm_busy; + bm_ctrl_error = priv->params->ctrl.bm_error; + + mask = bm_ctrl_busy | bm_ctrl_error | flags; + + for (count = 10000; count >= 0; count--) { + c = readl(base + IMX_OCOTP_ADDR_CTRL); + if (!(c & mask)) + break; + cpu_relax(); + } + + if (count < 0) { + /* HW_OCOTP_CTRL[ERROR] will be set under the following + * conditions: + * - A write is performed to a shadow register during a shadow + * reload (essentially, while HW_OCOTP_CTRL[RELOAD_SHADOWS] is + * set. In addition, the contents of the shadow register shall + * not be updated. + * - A write is performed to a shadow register which has been + * locked. + * - A read is performed to from a shadow register which has + * been read locked. + * - A program is performed to a fuse word which has been locked + * - A read is performed to from a fuse word which has been read + * locked. + */ + if (c & bm_ctrl_error) + return -EPERM; + return -ETIMEDOUT; + } + + return 0; +} + +static void imx_ocotp_clr_err_if_set(struct ocotp_priv *priv) +{ + u32 c, bm_ctrl_error; + void __iomem *base = priv->base; + + bm_ctrl_error = priv->params->ctrl.bm_error; + + c = readl(base + IMX_OCOTP_ADDR_CTRL); + if (!(c & bm_ctrl_error)) + return; + + writel(bm_ctrl_error, base + IMX_OCOTP_ADDR_CTRL_CLR); +} + +static int imx_ocotp_read(void *context, unsigned int offset, + void *val, size_t bytes) +{ + struct ocotp_priv *priv = context; + unsigned int count; + u8 *buf, *p; + int i, ret; + u32 index, num_bytes; + + index = offset >> 2; + num_bytes = round_up((offset % 4) + bytes, 4); + count = num_bytes >> 2; + + if (count > (priv->params->nregs - index)) + count = priv->params->nregs - index; + + p = kzalloc(num_bytes, GFP_KERNEL); + if (!p) + return -ENOMEM; + + mutex_lock(&ocotp_mutex); + + buf = p; + + ret = clk_prepare_enable(priv->clk); + if (ret < 0) { + mutex_unlock(&ocotp_mutex); + dev_err(priv->dev, "failed to prepare/enable ocotp clk\n"); + kfree(p); + return ret; + } + + ret = imx_ocotp_wait_for_busy(priv, 0); + if (ret < 0) { + dev_err(priv->dev, "timeout during read setup\n"); + goto read_end; + } + + for (i = index; i < (index + count); i++) { + *(u32 *)buf = readl(priv->base + IMX_OCOTP_OFFSET_B0W0 + + i * IMX_OCOTP_OFFSET_PER_WORD); + + /* 47.3.1.2 + * For "read locked" registers 0xBADABADA will be returned and + * HW_OCOTP_CTRL[ERROR] will be set. It must be cleared by + * software before any new write, read or reload access can be + * issued + */ + if (*((u32 *)buf) == IMX_OCOTP_READ_LOCKED_VAL) + imx_ocotp_clr_err_if_set(priv); + + buf += 4; + } + + index = offset % 4; + memcpy(val, &p[index], bytes); + +read_end: + clk_disable_unprepare(priv->clk); + mutex_unlock(&ocotp_mutex); + + kfree(p); + + return ret; +} + +static int imx_ocotp_cell_pp(void *context, const char *id, unsigned int offset, + void *data, size_t bytes) +{ + struct ocotp_priv *priv = context; + + /* Deal with some post processing of nvmem cell data */ + if (id && !strcmp(id, "mac-address")) { + if (priv->params->reverse_mac_address) { + u8 *buf = data; + int i; + + for (i = 0; i < bytes/2; i++) + swap(buf[i], buf[bytes - i - 1]); + } + } + + return 0; +} + +static void imx_ocotp_set_imx6_timing(struct ocotp_priv *priv) +{ + unsigned long clk_rate; + unsigned long strobe_read, relax, strobe_prog; + u32 timing; + + /* 47.3.1.3.1 + * Program HW_OCOTP_TIMING[STROBE_PROG] and HW_OCOTP_TIMING[RELAX] + * fields with timing values to match the current frequency of the + * ipg_clk. OTP writes will work at maximum bus frequencies as long + * as the HW_OCOTP_TIMING parameters are set correctly. + * + * Note: there are minimum timings required to ensure an OTP fuse burns + * correctly that are independent of the ipg_clk. Those values are not + * formally documented anywhere however, working from the minimum + * timings given in u-boot we can say: + * + * - Minimum STROBE_PROG time is 10 microseconds. Intuitively 10 + * microseconds feels about right as representative of a minimum time + * to physically burn out a fuse. + * + * - Minimum STROBE_READ i.e. the time to wait post OTP fuse burn before + * performing another read is 37 nanoseconds + * + * - Minimum RELAX timing is 17 nanoseconds. This final RELAX minimum + * timing is not entirely clear the documentation says "This + * count value specifies the time to add to all default timing + * parameters other than the Tpgm and Trd. It is given in number + * of ipg_clk periods." where Tpgm and Trd refer to STROBE_PROG + * and STROBE_READ respectively. What the other timing parameters + * are though, is not specified. Experience shows a zero RELAX + * value will mess up a re-load of the shadow registers post OTP + * burn. + */ + clk_rate = clk_get_rate(priv->clk); + + relax = DIV_ROUND_UP(clk_rate * TIMING_RELAX_NS, 1000000000) - 1; + strobe_read = DIV_ROUND_UP(clk_rate * TIMING_STROBE_READ_NS, + 1000000000); + strobe_read += 2 * (relax + 1) - 1; + strobe_prog = DIV_ROUND_CLOSEST(clk_rate * TIMING_STROBE_PROG_US, + 1000000); + strobe_prog += 2 * (relax + 1) - 1; + + timing = readl(priv->base + IMX_OCOTP_ADDR_TIMING) & 0x0FC00000; + timing |= strobe_prog & 0x00000FFF; + timing |= (relax << 12) & 0x0000F000; + timing |= (strobe_read << 16) & 0x003F0000; + + writel(timing, priv->base + IMX_OCOTP_ADDR_TIMING); +} + +static void imx_ocotp_set_imx7_timing(struct ocotp_priv *priv) +{ + unsigned long clk_rate; + u64 fsource, strobe_prog; + u32 timing; + + /* i.MX 7Solo Applications Processor Reference Manual, Rev. 0.1 + * 6.4.3.3 + */ + clk_rate = clk_get_rate(priv->clk); + fsource = DIV_ROUND_UP_ULL((u64)clk_rate * DEF_FSOURCE, + NSEC_PER_SEC) + 1; + strobe_prog = DIV_ROUND_CLOSEST_ULL((u64)clk_rate * DEF_STROBE_PROG, + NSEC_PER_SEC) + 1; + + timing = strobe_prog & 0x00000FFF; + timing |= (fsource << 12) & 0x000FF000; + + writel(timing, priv->base + IMX_OCOTP_ADDR_TIMING); +} + +static int imx_ocotp_write(void *context, unsigned int offset, void *val, + size_t bytes) +{ + struct ocotp_priv *priv = context; + u32 *buf = val; + int ret; + + u32 ctrl; + u8 waddr; + u8 word = 0; + + /* allow only writing one complete OTP word at a time */ + if ((bytes != priv->config->word_size) || + (offset % priv->config->word_size)) + return -EINVAL; + + mutex_lock(&ocotp_mutex); + + ret = clk_prepare_enable(priv->clk); + if (ret < 0) { + mutex_unlock(&ocotp_mutex); + dev_err(priv->dev, "failed to prepare/enable ocotp clk\n"); + return ret; + } + + /* Setup the write timing values */ + priv->params->set_timing(priv); + + /* 47.3.1.3.2 + * Check that HW_OCOTP_CTRL[BUSY] and HW_OCOTP_CTRL[ERROR] are clear. + * Overlapped accesses are not supported by the controller. Any pending + * write or reload must be completed before a write access can be + * requested. + */ + ret = imx_ocotp_wait_for_busy(priv, 0); + if (ret < 0) { + dev_err(priv->dev, "timeout during timing setup\n"); + goto write_end; + } + + /* 47.3.1.3.3 + * Write the requested address to HW_OCOTP_CTRL[ADDR] and program the + * unlock code into HW_OCOTP_CTRL[WR_UNLOCK]. This must be programmed + * for each write access. The lock code is documented in the register + * description. Both the unlock code and address can be written in the + * same operation. + */ + if (priv->params->bank_address_words != 0) { + /* + * In banked/i.MX7 mode the OTP register bank goes into waddr + * see i.MX 7Solo Applications Processor Reference Manual, Rev. + * 0.1 section 6.4.3.1 + */ + offset = offset / priv->config->word_size; + waddr = offset / priv->params->bank_address_words; + word = offset & (priv->params->bank_address_words - 1); + } else { + /* + * Non-banked i.MX6 mode. + * OTP write/read address specifies one of 128 word address + * locations + */ + waddr = offset / 4; + } + + ctrl = readl(priv->base + IMX_OCOTP_ADDR_CTRL); + ctrl &= ~priv->params->ctrl.bm_addr; + ctrl |= waddr & priv->params->ctrl.bm_addr; + ctrl |= IMX_OCOTP_WR_UNLOCK; + + writel(ctrl, priv->base + IMX_OCOTP_ADDR_CTRL); + + /* 47.3.1.3.4 + * Write the data to the HW_OCOTP_DATA register. This will automatically + * set HW_OCOTP_CTRL[BUSY] and clear HW_OCOTP_CTRL[WR_UNLOCK]. To + * protect programming same OTP bit twice, before program OCOTP will + * automatically read fuse value in OTP and use read value to mask + * program data. The controller will use masked program data to program + * a 32-bit word in the OTP per the address in HW_OCOTP_CTRL[ADDR]. Bit + * fields with 1's will result in that OTP bit being programmed. Bit + * fields with 0's will be ignored. At the same time that the write is + * accepted, the controller makes an internal copy of + * HW_OCOTP_CTRL[ADDR] which cannot be updated until the next write + * sequence is initiated. This copy guarantees that erroneous writes to + * HW_OCOTP_CTRL[ADDR] will not affect an active write operation. It + * should also be noted that during the programming HW_OCOTP_DATA will + * shift right (with zero fill). This shifting is required to program + * the OTP serially. During the write operation, HW_OCOTP_DATA cannot be + * modified. + * Note: on i.MX7 there are four data fields to write for banked write + * with the fuse blowing operation only taking place after data0 + * has been written. This is why data0 must always be the last + * register written. + */ + if (priv->params->bank_address_words != 0) { + /* Banked/i.MX7 mode */ + switch (word) { + case 0: + writel(0, priv->base + IMX_OCOTP_ADDR_DATA1); + writel(0, priv->base + IMX_OCOTP_ADDR_DATA2); + writel(0, priv->base + IMX_OCOTP_ADDR_DATA3); + writel(*buf, priv->base + IMX_OCOTP_ADDR_DATA0); + break; + case 1: + writel(*buf, priv->base + IMX_OCOTP_ADDR_DATA1); + writel(0, priv->base + IMX_OCOTP_ADDR_DATA2); + writel(0, priv->base + IMX_OCOTP_ADDR_DATA3); + writel(0, priv->base + IMX_OCOTP_ADDR_DATA0); + break; + case 2: + writel(0, priv->base + IMX_OCOTP_ADDR_DATA1); + writel(*buf, priv->base + IMX_OCOTP_ADDR_DATA2); + writel(0, priv->base + IMX_OCOTP_ADDR_DATA3); + writel(0, priv->base + IMX_OCOTP_ADDR_DATA0); + break; + case 3: + writel(0, priv->base + IMX_OCOTP_ADDR_DATA1); + writel(0, priv->base + IMX_OCOTP_ADDR_DATA2); + writel(*buf, priv->base + IMX_OCOTP_ADDR_DATA3); + writel(0, priv->base + IMX_OCOTP_ADDR_DATA0); + break; + } + } else { + /* Non-banked i.MX6 mode */ + writel(*buf, priv->base + IMX_OCOTP_ADDR_DATA0); + } + + /* 47.4.1.4.5 + * Once complete, the controller will clear BUSY. A write request to a + * protected or locked region will result in no OTP access and no + * setting of HW_OCOTP_CTRL[BUSY]. In addition HW_OCOTP_CTRL[ERROR] will + * be set. It must be cleared by software before any new write access + * can be issued. + */ + ret = imx_ocotp_wait_for_busy(priv, 0); + if (ret < 0) { + if (ret == -EPERM) { + dev_err(priv->dev, "failed write to locked region"); + imx_ocotp_clr_err_if_set(priv); + } else { + dev_err(priv->dev, "timeout during data write\n"); + } + goto write_end; + } + + /* 47.3.1.4 + * Write Postamble: Due to internal electrical characteristics of the + * OTP during writes, all OTP operations following a write must be + * separated by 2 us after the clearing of HW_OCOTP_CTRL_BUSY following + * the write. + */ + udelay(2); + + /* reload all shadow registers */ + writel(priv->params->ctrl.bm_rel_shadows, + priv->base + IMX_OCOTP_ADDR_CTRL_SET); + ret = imx_ocotp_wait_for_busy(priv, + priv->params->ctrl.bm_rel_shadows); + if (ret < 0) + dev_err(priv->dev, "timeout during shadow register reload\n"); + +write_end: + clk_disable_unprepare(priv->clk); + mutex_unlock(&ocotp_mutex); + return ret < 0 ? ret : bytes; +} + +static struct nvmem_config imx_ocotp_nvmem_config = { + .name = "imx-ocotp", + .read_only = false, + .word_size = 4, + .stride = 1, + .reg_read = imx_ocotp_read, + .reg_write = imx_ocotp_write, + .cell_post_process = imx_ocotp_cell_pp, +}; + +static const struct ocotp_params imx6q_params = { + .nregs = 128, + .bank_address_words = 0, + .set_timing = imx_ocotp_set_imx6_timing, + .ctrl = IMX_OCOTP_BM_CTRL_DEFAULT, +}; + +static const struct ocotp_params imx6sl_params = { + .nregs = 64, + .bank_address_words = 0, + .set_timing = imx_ocotp_set_imx6_timing, + .ctrl = IMX_OCOTP_BM_CTRL_DEFAULT, +}; + +static const struct ocotp_params imx6sll_params = { + .nregs = 80, + .bank_address_words = 0, + .set_timing = imx_ocotp_set_imx6_timing, + .ctrl = IMX_OCOTP_BM_CTRL_DEFAULT, +}; + +static const struct ocotp_params imx6sx_params = { + .nregs = 128, + .bank_address_words = 0, + .set_timing = imx_ocotp_set_imx6_timing, + .ctrl = IMX_OCOTP_BM_CTRL_DEFAULT, +}; + +static const struct ocotp_params imx6ul_params = { + .nregs = 144, + .bank_address_words = 0, + .set_timing = imx_ocotp_set_imx6_timing, + .ctrl = IMX_OCOTP_BM_CTRL_DEFAULT, +}; + +static const struct ocotp_params imx6ull_params = { + .nregs = 80, + .bank_address_words = 0, + .set_timing = imx_ocotp_set_imx6_timing, + .ctrl = IMX_OCOTP_BM_CTRL_DEFAULT, +}; + +static const struct ocotp_params imx7d_params = { + .nregs = 64, + .bank_address_words = 4, + .set_timing = imx_ocotp_set_imx7_timing, + .ctrl = IMX_OCOTP_BM_CTRL_DEFAULT, +}; + +static const struct ocotp_params imx7ulp_params = { + .nregs = 256, + .bank_address_words = 0, + .ctrl = IMX_OCOTP_BM_CTRL_DEFAULT, +}; + +static const struct ocotp_params imx8mq_params = { + .nregs = 256, + .bank_address_words = 0, + .set_timing = imx_ocotp_set_imx6_timing, + .ctrl = IMX_OCOTP_BM_CTRL_DEFAULT, + .reverse_mac_address = true, +}; + +static const struct ocotp_params imx8mm_params = { + .nregs = 256, + .bank_address_words = 0, + .set_timing = imx_ocotp_set_imx6_timing, + .ctrl = IMX_OCOTP_BM_CTRL_DEFAULT, + .reverse_mac_address = true, +}; + +static const struct ocotp_params imx8mn_params = { + .nregs = 256, + .bank_address_words = 0, + .set_timing = imx_ocotp_set_imx6_timing, + .ctrl = IMX_OCOTP_BM_CTRL_DEFAULT, + .reverse_mac_address = true, +}; + +static const struct ocotp_params imx8mp_params = { + .nregs = 384, + .bank_address_words = 0, + .set_timing = imx_ocotp_set_imx6_timing, + .ctrl = IMX_OCOTP_BM_CTRL_8MP, + .reverse_mac_address = true, +}; + +static const struct of_device_id imx_ocotp_dt_ids[] = { + { .compatible = "fsl,imx6q-ocotp", .data = &imx6q_params }, + { .compatible = "fsl,imx6sl-ocotp", .data = &imx6sl_params }, + { .compatible = "fsl,imx6sx-ocotp", .data = &imx6sx_params }, + { .compatible = "fsl,imx6ul-ocotp", .data = &imx6ul_params }, + { .compatible = "fsl,imx6ull-ocotp", .data = &imx6ull_params }, + { .compatible = "fsl,imx7d-ocotp", .data = &imx7d_params }, + { .compatible = "fsl,imx6sll-ocotp", .data = &imx6sll_params }, + { .compatible = "fsl,imx7ulp-ocotp", .data = &imx7ulp_params }, + { .compatible = "fsl,imx8mq-ocotp", .data = &imx8mq_params }, + { .compatible = "fsl,imx8mm-ocotp", .data = &imx8mm_params }, + { .compatible = "fsl,imx8mn-ocotp", .data = &imx8mn_params }, + { .compatible = "fsl,imx8mp-ocotp", .data = &imx8mp_params }, + { }, +}; +MODULE_DEVICE_TABLE(of, imx_ocotp_dt_ids); + +static int imx_ocotp_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct ocotp_priv *priv; + struct nvmem_device *nvmem; + + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + priv->dev = dev; + + priv->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(priv->base)) + return PTR_ERR(priv->base); + + priv->clk = devm_clk_get(dev, NULL); + if (IS_ERR(priv->clk)) + return PTR_ERR(priv->clk); + + priv->params = of_device_get_match_data(&pdev->dev); + imx_ocotp_nvmem_config.size = 4 * priv->params->nregs; + imx_ocotp_nvmem_config.dev = dev; + imx_ocotp_nvmem_config.priv = priv; + priv->config = &imx_ocotp_nvmem_config; + + clk_prepare_enable(priv->clk); + imx_ocotp_clr_err_if_set(priv); + clk_disable_unprepare(priv->clk); + + nvmem = devm_nvmem_register(dev, &imx_ocotp_nvmem_config); + + return PTR_ERR_OR_ZERO(nvmem); +} + +static struct platform_driver imx_ocotp_driver = { + .probe = imx_ocotp_probe, + .driver = { + .name = "imx_ocotp", + .of_match_table = imx_ocotp_dt_ids, + }, +}; +module_platform_driver(imx_ocotp_driver); + +MODULE_AUTHOR("Philipp Zabel <p.zabel@pengutronix.de>"); +MODULE_DESCRIPTION("i.MX6/i.MX7 OCOTP fuse box driver"); +MODULE_LICENSE("GPL v2"); |