u-boot/arch/arm/cpu/armv7/omap5/dra7xx_iodelay.c

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/*
* (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");
}
}