diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/misc/Makefile | 1 | ||||
| -rw-r--r-- | drivers/misc/mxs_ocotp.c | 311 |
2 files changed, 312 insertions, 0 deletions
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile index c77e40a..0f9f6f1 100644 --- a/drivers/misc/Makefile +++ b/drivers/misc/Makefile @@ -16,6 +16,7 @@ obj-$(CONFIG_FSL_IIM) += fsl_iim.o obj-$(CONFIG_GPIO_LED) += gpio_led.o obj-$(CONFIG_FSL_MC9SDZ60) += mc9sdz60.o obj-$(CONFIG_MXC_OCOTP) += mxc_ocotp.o +obj-$(CONFIG_MXS_OCOTP) += mxs_ocotp.o obj-$(CONFIG_NS87308) += ns87308.o obj-$(CONFIG_PDSP188x) += pdsp188x.o obj-$(CONFIG_STATUS_LED) += status_led.o diff --git a/drivers/misc/mxs_ocotp.c b/drivers/misc/mxs_ocotp.c new file mode 100644 index 0000000..545d3eb --- /dev/null +++ b/drivers/misc/mxs_ocotp.c @@ -0,0 +1,311 @@ +/* + * Freescale i.MX28 OCOTP Driver + * + * Copyright (C) 2014 Marek Vasut <marex@denx.de> + * + * SPDX-License-Identifier: GPL-2.0+ + * + * Note: The i.MX23/i.MX28 OCOTP block is a predecessor to the OCOTP block + * used in i.MX6 . While these blocks are very similar at the first + * glance, by digging deeper, one will notice differences (like the + * tight dependence on MXS power block, some completely new registers + * etc.) which would make common driver an ifdef nightmare :-( + */ + +#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> +#include <asm/arch/sys_proto.h> + +#define MXS_OCOTP_TIMEOUT 100000 + +static struct mxs_ocotp_regs *ocotp_regs = + (struct mxs_ocotp_regs *)MXS_OCOTP_BASE; +static struct mxs_power_regs *power_regs = + (struct mxs_power_regs *)MXS_POWER_BASE; +static struct mxs_clkctrl_regs *clkctrl_regs = + (struct mxs_clkctrl_regs *)MXS_CLKCTRL_BASE; + +static int mxs_ocotp_wait_busy_clear(void) +{ + uint32_t reg; + int timeout = MXS_OCOTP_TIMEOUT; + + while (--timeout) { + reg = readl(&ocotp_regs->hw_ocotp_ctrl); + if (!(reg & OCOTP_CTRL_BUSY)) + break; + udelay(10); + } + + if (!timeout) + return -EINVAL; + + /* Wait a little as per FSL datasheet's 'write postamble' section. */ + udelay(10); + + return 0; +} + +static void mxs_ocotp_clear_error(void) +{ + writel(OCOTP_CTRL_ERROR, &ocotp_regs->hw_ocotp_ctrl_clr); +} + +static int mxs_ocotp_read_bank_open(bool open) +{ + int ret = 0; + + if (open) { + writel(OCOTP_CTRL_RD_BANK_OPEN, + &ocotp_regs->hw_ocotp_ctrl_set); + + /* + * Wait before polling the BUSY bit, since the BUSY bit might + * be asserted only after a few HCLK cycles and if we were to + * poll immediatelly, we could miss the busy bit. + */ + udelay(10); + ret = mxs_ocotp_wait_busy_clear(); + } else { + writel(OCOTP_CTRL_RD_BANK_OPEN, + &ocotp_regs->hw_ocotp_ctrl_clr); + } + + return ret; +} + +static void mxs_ocotp_scale_vddio(bool enter, uint32_t *val) +{ + uint32_t scale_val; + + if (enter) { + /* + * Enter the fuse programming VDDIO voltage setup. We start + * scaling the voltage from it's current value down to 2.8V + * which is the one and only correct voltage for programming + * the OCOTP fuses (according to datasheet). + */ + scale_val = readl(&power_regs->hw_power_vddioctrl); + scale_val &= POWER_VDDIOCTRL_TRG_MASK; + + /* Return the original voltage. */ + *val = scale_val; + + /* + * Start scaling VDDIO down to 0x2, which is 2.8V . Actually, + * the value 0x0 should be 2.8V, but that's not the case on + * most designs due to load etc., so we play safe. Undervolt + * can actually cause incorrect programming of the fuses and + * or reboots of the board. + */ + while (scale_val > 2) { + clrsetbits_le32(&power_regs->hw_power_vddioctrl, + POWER_VDDIOCTRL_TRG_MASK, --scale_val); + udelay(500); + } + } else { + /* Start scaling VDDIO up to original value . */ + for (scale_val = 2; scale_val <= *val; scale_val++) { + clrsetbits_le32(&power_regs->hw_power_vddioctrl, + POWER_VDDIOCTRL_TRG_MASK, scale_val); + udelay(500); + } + } + + mdelay(10); +} + +static int mxs_ocotp_wait_hclk_ready(void) +{ + uint32_t reg, timeout = MXS_OCOTP_TIMEOUT; + + while (--timeout) { + reg = readl(&clkctrl_regs->hw_clkctrl_hbus); + if (!(reg & CLKCTRL_HBUS_ASM_BUSY)) + break; + } + + if (!timeout) + return -EINVAL; + + return 0; +} + +static int mxs_ocotp_scale_hclk(bool enter, uint32_t *val) +{ + uint32_t scale_val; + int ret; + + ret = mxs_ocotp_wait_hclk_ready(); + if (ret) + return ret; + + /* Set CPU bypass */ + writel(CLKCTRL_CLKSEQ_BYPASS_CPU, + &clkctrl_regs->hw_clkctrl_clkseq_set); + + if (enter) { + /* Return the original HCLK clock speed. */ + *val = readl(&clkctrl_regs->hw_clkctrl_hbus); + *val &= CLKCTRL_HBUS_DIV_MASK; + + /* Scale the HCLK to 454/19 = 23.9 MHz . */ + scale_val = (~19) << CLKCTRL_HBUS_DIV_OFFSET; + scale_val &= CLKCTRL_HBUS_DIV_MASK; + } else { + /* Scale the HCLK back to original frequency. */ + scale_val = (~(*val)) << CLKCTRL_HBUS_DIV_OFFSET; + scale_val &= CLKCTRL_HBUS_DIV_MASK; + } + + writel(CLKCTRL_HBUS_DIV_MASK, + &clkctrl_regs->hw_clkctrl_hbus_set); + writel(scale_val, + &clkctrl_regs->hw_clkctrl_hbus_clr); + + mdelay(10); + + ret = mxs_ocotp_wait_hclk_ready(); + if (ret) + return ret; + + /* Disable CPU bypass */ + writel(CLKCTRL_CLKSEQ_BYPASS_CPU, + &clkctrl_regs->hw_clkctrl_clkseq_clr); + + mdelay(10); + + return 0; +} + +static int mxs_ocotp_write_fuse(uint32_t addr, uint32_t mask) +{ + uint32_t hclk_val, vddio_val; + int ret; + + /* Make sure the banks are closed for reading. */ + ret = mxs_ocotp_read_bank_open(0); + if (ret) { + puts("Failed closing banks for reading!\n"); + return ret; + } + + ret = mxs_ocotp_scale_hclk(1, &hclk_val); + if (ret) { + puts("Failed scaling down the HCLK!\n"); + return ret; + } + mxs_ocotp_scale_vddio(1, &vddio_val); + + ret = mxs_ocotp_wait_busy_clear(); + if (ret) { + puts("Failed waiting for ready state!\n"); + goto fail; + } + + /* Program the fuse address */ + writel(addr | OCOTP_CTRL_WR_UNLOCK_KEY, &ocotp_regs->hw_ocotp_ctrl); + + /* Program the data. */ + writel(mask, &ocotp_regs->hw_ocotp_data); + + udelay(10); + + ret = mxs_ocotp_wait_busy_clear(); + if (ret) { + puts("Failed waiting for ready state!\n"); + goto fail; + } + +fail: + mxs_ocotp_scale_vddio(0, &vddio_val); + ret = mxs_ocotp_scale_hclk(0, &hclk_val); + if (ret) { + puts("Failed scaling up the HCLK!\n"); + return ret; + } + + return ret; +} + +static int mxs_ocotp_read_fuse(uint32_t reg, uint32_t *val) +{ + int ret; + + /* Register offset from CUST0 */ + reg = ((uint32_t)&ocotp_regs->hw_ocotp_cust0) + (reg << 4); + + ret = mxs_ocotp_wait_busy_clear(); + if (ret) { + puts("Failed waiting for ready state!\n"); + return ret; + } + + mxs_ocotp_clear_error(); + + ret = mxs_ocotp_read_bank_open(1); + if (ret) { + puts("Failed opening banks for reading!\n"); + return ret; + } + + *val = readl(reg); + + ret = mxs_ocotp_read_bank_open(0); + if (ret) { + puts("Failed closing banks for reading!\n"); + return ret; + } + + return ret; +} + +static int mxs_ocotp_valid(u32 bank, u32 word) +{ + if (bank > 4) + return -EINVAL; + if (word > 7) + return -EINVAL; + return 0; +} + +/* + * The 'fuse' command API + */ +int fuse_read(u32 bank, u32 word, u32 *val) +{ + int ret; + + ret = mxs_ocotp_valid(bank, word); + if (ret) + return ret; + + return mxs_ocotp_read_fuse((bank << 3) | word, val); +} + +int fuse_prog(u32 bank, u32 word, u32 val) +{ + int ret; + + ret = mxs_ocotp_valid(bank, word); + if (ret) + return ret; + + return mxs_ocotp_write_fuse((bank << 3) | word, val); +} + +int fuse_sense(u32 bank, u32 word, u32 *val) +{ + /* We do not support sensing :-( */ + return -EINVAL; +} + +int fuse_override(u32 bank, u32 word, u32 val) +{ + /* We do not support overriding :-( */ + return -EINVAL; +} |