diff options
Diffstat (limited to 'arch/arm/cpu/armv7/omap5/dra7xx_iodelay.c')
| -rw-r--r-- | arch/arm/cpu/armv7/omap5/dra7xx_iodelay.c | 238 |
1 files changed, 238 insertions, 0 deletions
diff --git a/arch/arm/cpu/armv7/omap5/dra7xx_iodelay.c b/arch/arm/cpu/armv7/omap5/dra7xx_iodelay.c new file mode 100644 index 0000000000..9fa6e6991f --- /dev/null +++ b/arch/arm/cpu/armv7/omap5/dra7xx_iodelay.c @@ -0,0 +1,238 @@ +/* + * (C) Copyright 2015 + * Texas Instruments Incorporated, <www.ti.com> + * + * Lokesh Vutla <lokeshvutla@ti.com> + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include <common.h> +#include <asm/utils.h> +#include <asm/arch/dra7xx_iodelay.h> +#include <asm/arch/omap.h> +#include <asm/arch/sys_proto.h> +#include <asm/arch/clock.h> +#include <asm/arch/mux_dra7xx.h> +#include <asm/omap_common.h> + +static int isolate_io(u32 isolate) +{ + if (isolate) { + clrsetbits_le32((*ctrl)->control_pbias, SDCARD_PWRDNZ, + SDCARD_PWRDNZ); + clrsetbits_le32((*ctrl)->control_pbias, SDCARD_BIAS_PWRDNZ, + SDCARD_BIAS_PWRDNZ); + } + + /* Override control on ISOCLKIN signal to IO pad ring. */ + clrsetbits_le32((*prcm)->prm_io_pmctrl, PMCTRL_ISOCLK_OVERRIDE_MASK, + PMCTRL_ISOCLK_OVERRIDE_CTRL); + if (!wait_on_value(PMCTRL_ISOCLK_STATUS_MASK, PMCTRL_ISOCLK_STATUS_MASK, + (u32 *)(*prcm)->prm_io_pmctrl, LDELAY)) + return ERR_DEISOLATE_IO << isolate; + + /* Isolate/Deisolate IO */ + clrsetbits_le32((*ctrl)->ctrl_core_sma_sw_0, CTRL_ISOLATE_MASK, + isolate << CTRL_ISOLATE_SHIFT); + /* Dummy read to add delay t > 10ns */ + readl((*ctrl)->ctrl_core_sma_sw_0); + + /* Return control on ISOCLKIN to hardware */ + clrsetbits_le32((*prcm)->prm_io_pmctrl, PMCTRL_ISOCLK_OVERRIDE_MASK, + PMCTRL_ISOCLK_NOT_OVERRIDE_CTRL); + if (!wait_on_value(PMCTRL_ISOCLK_STATUS_MASK, + 0 << PMCTRL_ISOCLK_STATUS_SHIFT, + (u32 *)(*prcm)->prm_io_pmctrl, LDELAY)) + return ERR_DEISOLATE_IO << isolate; + + return 0; +} + +static int calibrate_iodelay(u32 base) +{ + u32 reg; + + /* Configure REFCLK period */ + reg = readl(base + CFG_REG_2_OFFSET); + reg &= ~CFG_REG_REFCLK_PERIOD_MASK; + reg |= CFG_REG_REFCLK_PERIOD; + writel(reg, base + CFG_REG_2_OFFSET); + + /* Initiate Calibration */ + clrsetbits_le32(base + CFG_REG_0_OFFSET, CFG_REG_CALIB_STRT_MASK, + CFG_REG_CALIB_STRT << CFG_REG_CALIB_STRT_SHIFT); + if (!wait_on_value(CFG_REG_CALIB_STRT_MASK, CFG_REG_CALIB_END, + (u32 *)(base + CFG_REG_0_OFFSET), LDELAY)) + return ERR_CALIBRATE_IODELAY; + + return 0; +} + +static int update_delay_mechanism(u32 base) +{ + /* Initiate the reload of calibrated values. */ + clrsetbits_le32(base + CFG_REG_0_OFFSET, CFG_REG_ROM_READ_MASK, + CFG_REG_ROM_READ_START); + if (!wait_on_value(CFG_REG_ROM_READ_MASK, CFG_REG_ROM_READ_END, + (u32 *)(base + CFG_REG_0_OFFSET), LDELAY)) + return ERR_UPDATE_DELAY; + + return 0; +} + +static u32 calculate_delay(u32 base, u16 offset, u16 den) +{ + u16 refclk_period, dly_cnt, ref_cnt; + u32 reg, q, r; + + refclk_period = readl(base + CFG_REG_2_OFFSET) & + CFG_REG_REFCLK_PERIOD_MASK; + + reg = readl(base + offset); + dly_cnt = (reg & CFG_REG_DLY_CNT_MASK) >> CFG_REG_DLY_CNT_SHIFT; + ref_cnt = (reg & CFG_REG_REF_CNT_MASK) >> CFG_REG_REF_CNT_SHIFT; + + if (!dly_cnt || !den) + return 0; + + /* + * To avoid overflow and integer truncation, delay value + * is calculated as quotient + remainder. + */ + q = 5 * ((ref_cnt * refclk_period) / (dly_cnt * den)); + r = (10 * ((ref_cnt * refclk_period) % (dly_cnt * den))) / + (2 * dly_cnt * den); + + return q + r; +} + +static u32 get_cfg_reg(u16 a_delay, u16 g_delay, u32 cpde, u32 fpde) +{ + u32 g_delay_coarse, g_delay_fine; + u32 a_delay_coarse, a_delay_fine; + u32 c_elements, f_elements; + u32 total_delay, reg = 0; + + g_delay_coarse = g_delay / 920; + g_delay_fine = ((g_delay % 920) * 10) / 60; + + a_delay_coarse = a_delay / cpde; + a_delay_fine = ((a_delay % cpde) * 10) / fpde; + + c_elements = g_delay_coarse + a_delay_coarse; + f_elements = (g_delay_fine + a_delay_fine) / 10; + + if (f_elements > 22) { + total_delay = c_elements * cpde + f_elements * fpde; + + c_elements = total_delay / cpde; + f_elements = (total_delay % cpde) / fpde; + } + + reg = (c_elements << CFG_X_COARSE_DLY_SHIFT) & CFG_X_COARSE_DLY_MASK; + reg |= (f_elements << CFG_X_FINE_DLY_SHIFT) & CFG_X_FINE_DLY_MASK; + reg |= CFG_X_SIGNATURE << CFG_X_SIGNATURE_SHIFT; + reg |= CFG_X_LOCK << CFG_X_LOCK_SHIFT; + + return reg; +} + +static int do_set_iodelay(u32 base, struct iodelay_cfg_entry const *array, + int niodelays) +{ + struct iodelay_cfg_entry *iodelay = (struct iodelay_cfg_entry *)array; + u32 reg, cpde, fpde, i; + + if (!niodelays) + return 0; + + cpde = calculate_delay((*ctrl)->iodelay_config_base, CFG_REG_3_OFFSET, + 88); + if (!cpde) + return ERR_CPDE; + + fpde = calculate_delay((*ctrl)->iodelay_config_base, CFG_REG_4_OFFSET, + 264); + if (!fpde) + return ERR_FPDE; + + for (i = 0; i < niodelays; i++, iodelay++) { + reg = get_cfg_reg(iodelay->a_delay, iodelay->g_delay, cpde, + fpde); + writel(reg, base + iodelay->offset); + } + + return 0; +} + +void __recalibrate_iodelay(struct pad_conf_entry const *pad, int npads, + struct iodelay_cfg_entry const *iodelay, + int niodelays) +{ + int ret = 0; + + /* IO recalibration should be done only from SRAM */ + if (OMAP_INIT_CONTEXT_SPL != omap_hw_init_context()) { + puts("IODELAY recalibration called from invalid context - use only from SPL in SRAM\n"); + return; + } + + /* unlock IODELAY CONFIG registers */ + writel(CFG_IODELAY_UNLOCK_KEY, (*ctrl)->iodelay_config_base + + CFG_REG_8_OFFSET); + + ret = calibrate_iodelay((*ctrl)->iodelay_config_base); + if (ret) + goto err; + + ret = isolate_io(ISOLATE_IO); + if (ret) + goto err; + + ret = update_delay_mechanism((*ctrl)->iodelay_config_base); + if (ret) + goto err; + + /* Configure Mux settings */ + do_set_mux32((*ctrl)->control_padconf_core_base, pad, npads); + + /* Configure Manual IO timing modes */ + ret = do_set_iodelay((*ctrl)->iodelay_config_base, iodelay, niodelays); + if (ret) + goto err; + + ret = isolate_io(DEISOLATE_IO); + +err: + /* lock IODELAY CONFIG registers */ + writel(CFG_IODELAY_LOCK_KEY, (*ctrl)->iodelay_config_base + + CFG_REG_8_OFFSET); + /* + * UART cannot be used during IO recalibration sequence as IOs are in + * isolation. So error handling and debug prints are done after + * complete IO delay recalibration sequence + */ + switch (ret) { + case ERR_CALIBRATE_IODELAY: + puts("IODELAY: IO delay calibration sequence failed\n"); + break; + case ERR_ISOLATE_IO: + puts("IODELAY: Isolation of Device IOs failed\n"); + break; + case ERR_UPDATE_DELAY: + puts("IODELAY: Delay mechanism update with new calibrated values failed\n"); + break; + case ERR_DEISOLATE_IO: + puts("IODELAY: De-isolation of Device IOs failed\n"); + break; + case ERR_CPDE: + puts("IODELAY: CPDE calculation failed\n"); + break; + case ERR_FPDE: + puts("IODELAY: FPDE calculation failed\n"); + break; + default: + debug("IODELAY: IO delay recalibration successfully completed\n"); + } +} |