Change SDRAM timings and other settings as necessary
on voltage and frequency changes. We calculate these
register settings based on data from the device data
sheet and inputs such a frequency, voltage state(stable
or ramping), temperature level etc.
TODO: frequency and voltage change handling needs to
be integrated with clock framework and regulator
framework respectively. This is not done today
due to missing pieces in the kernel.
Cc: Greg KH <greg@xxxxxxxxx>
Signed-off-by: Aneesh V <aneesh@xxxxxx>
---
v1:
- Added comment in commit log as well as code about
missing integration part that needs to be done in
future
- Removed some settings that were relevant only for
DDR3
- Correction in temperature derated value of tim3
- Added errata i735 and i728 workarounds. As part of
this we need to now maintain a list of all devices
in the driver and iterate through them in some cases
- Improved synchronization. Added protection for newly
identified cases of potential race conditions.
- Minor changes in patch organization. struct members
needed by this patch now defined here.
---
drivers/misc/emif.c | 894 ++++++++++++++++++++++++++++++++++++++++++++++++++-
drivers/misc/emif.h | 130 ++++++++-
2 files changed, 1020 insertions(+), 4 deletions(-)
diff --git a/drivers/misc/emif.c b/drivers/misc/emif.c
index f864640..1ca8165 100644
--- a/drivers/misc/emif.c
+++ b/drivers/misc/emif.c
@@ -21,6 +21,7 @@
#include <linux/seq_file.h>
#include <linux/module.h>
#include <linux/list.h>
+#include <linux/spinlock.h>
#include <misc/jedec_ddr.h>
#include "emif.h"
@@ -37,20 +38,595 @@
* @node: node in the device list
* @base: base address of memory-mapped IO registers.
* @dev: device pointer.
+ * @addressing table with addressing information from the spec
+ * @regs_cache: An array of 'struct emif_regs' that stores
+ * calculated register values for different
+ * frequencies, to avoid re-calculating them on
+ * each DVFS transition.
+ * @curr_regs: The set of register values used in the last
+ * frequency change (i.e. corresponding to the
+ * frequency in effect at the moment)
* @plat_data: Pointer to saved platform data.
*/
struct emif_data {
u8 duplicate;
u8 temperature_level;
+ u8 lpmode;
struct list_head node;
+ unsigned long irq_state;
void __iomem *base;
struct device *dev;
+ const struct lpddr2_addressing *addressing;
+ struct emif_regs *regs_cache[EMIF_MAX_NUM_FREQUENCIES];
+ struct emif_regs *curr_regs;
struct emif_platform_data *plat_data;
};
static struct emif_data *emif1;
+static spinlock_t emif_lock;
+static unsigned long irq_state;
+static u32 t_ck; /* DDR clock period in ps */
static LIST_HEAD(device_list);
+/*
+ * Calculate the period of DDR clock from frequency value
+ */
+static void set_ddr_clk_period(u32 freq)
+{
+ /* Divide 10^12 by frequency to get period in ps */
+ t_ck = (u32)DIV_ROUND_UP_ULL(1000000000000ull, freq);
+}
+
+/*
+ * Get the CL from SDRAM_CONFIG register
+ */
+static u32 get_cl(struct emif_data *emif)
+{
+ u32 cl;
+ void __iomem *base = emif->base;
+
+ cl = (readl(base + EMIF_SDRAM_CONFIG) & CL_MASK) >> CL_SHIFT;
+
+ return cl;
+}
+
+static void set_lpmode(struct emif_data *emif, u8 lpmode)
+{
+ u32 temp;
+ void __iomem *base = emif->base;
+
+ temp = readl(base + EMIF_POWER_MANAGEMENT_CONTROL);
+ temp &= ~LP_MODE_MASK;
+ temp |= (lpmode << LP_MODE_SHIFT);
+ writel(temp, base + EMIF_POWER_MANAGEMENT_CONTROL);
+}
+
+static void do_freq_update(void)
+{
+ struct emif_data *emif;
+
+ /*
+ * Workaround for errata i728: Disable LPMODE during FREQ_UPDATE
+ *
+ * i728 DESCRIPTION:
+ * The EMIF automatically puts the SDRAM into self-refresh mode
+ * after the EMIF has not performed accesses during
+ * EMIF_PWR_MGMT_CTRL[7:4] REG_SR_TIM number of DDR clock cycles
+ * and the EMIF_PWR_MGMT_CTRL[10:8] REG_LP_MODE bit field is set
+ * to 0x2. If during a small window the following three events
+ * occur:
+ * - The SR_TIMING counter expires
+ * - And frequency change is requested
+ * - And OCP access is requested
+ * Then it causes instable clock on the DDR interface.
+ *
+ * WORKAROUND
+ * To avoid the occurrence of the three events, the workaround
+ * is to disable the self-refresh when requesting a frequency
+ * change. Before requesting a frequency change the software must
+ * program EMIF_PWR_MGMT_CTRL[10:8] REG_LP_MODE to 0x0. When the
+ * frequency change has been done, the software can reprogram
+ * EMIF_PWR_MGMT_CTRL[10:8] REG_LP_MODE to 0x2
+ */
+ list_for_each_entry(emif, &device_list, node) {
+ if (emif->lpmode == EMIF_LP_MODE_SELF_REFRESH)
+ set_lpmode(emif, EMIF_LP_MODE_DISABLE);
+ }
+
+ /*
+ * TODO: Do FREQ_UPDATE here when an API
+ * is available for this as part of the new
+ * clock framework
+ */
+
+ list_for_each_entry(emif, &device_list, node) {
+ if (emif->lpmode == EMIF_LP_MODE_SELF_REFRESH)
+ set_lpmode(emif, EMIF_LP_MODE_SELF_REFRESH);
+ }
+}
+
+/* Find addressing table entry based on the device's type and density */
+static const struct lpddr2_addressing *get_addressing_table(
+ const struct ddr_device_info *device_info)
+{
+ u32 index, type, density;
+
+ type = device_info->type;
+ density = device_info->density;
+
+ switch (type) {
+ case DDR_TYPE_LPDDR2_S4:
+ index = density - 1;
+ break;
+ case DDR_TYPE_LPDDR2_S2:
+ switch (density) {
+ case DDR_DENSITY_1Gb:
+ case DDR_DENSITY_2Gb:
+ index = density + 3;
+ break;
+ default:
+ index = density - 1;
+ }
+ break;
+ default:
+ return NULL;
+ }
+
+ return &lpddr2_jedec_addressing_table[index];
+}
+
+/*
+ * Find the the right timing table from the array of timing
+ * tables of the device using DDR clock frequency
+ */
+static const struct lpddr2_timings *get_timings_table(struct emif_data *emif,
+ u32 freq)
+{
+ u32 i, min, max, freq_nearest;
+ const struct lpddr2_timings *timings = NULL;
+ const struct lpddr2_timings *timings_arr = emif->plat_data->timings;
+ struct device *dev = emif->dev;
+
+ /* Start with a very high frequency - 1GHz */
+ freq_nearest = 1000000000;
+
+ /*
+ * Find the timings table such that:
+ * 1. the frequency range covers the required frequency(safe) AND
+ * 2. the max_freq is closest to the required frequency(optimal)
+ */
+ for (i = 0; i < emif->plat_data->timings_arr_size; i++) {
+ max = timings_arr[i].max_freq;
+ min = timings_arr[i].min_freq;
+ if ((freq >= min) && (freq <= max) && (max < freq_nearest)) {
+ freq_nearest = max;
+ timings = &timings_arr[i];
+ }
+ }
+
+ if (!timings)
+ dev_err(dev, "%s: couldn't find timings for - %dHz\n",
+ __func__, freq);
+
+ dev_dbg(dev, "%s: timings table: freq %d, speed bin freq %d\n",
+ __func__, freq, freq_nearest);
+
+ return timings;
+}
+
+static u32 get_sdram_ref_ctrl_shdw(u32 freq,
+ const struct lpddr2_addressing *addressing)
+{
+ u32 ref_ctrl_shdw = 0, val = 0, freq_khz, t_refi;
+
+ /* Scale down frequency and t_refi to avoid overflow */
+ freq_khz = freq / 1000;
+ t_refi = addressing->tREFI_ns / 100;
+
+ /*
+ * refresh rate to be set is 'tREFI(in us) * freq in MHz
+ * division by 10000 to account for change in units
+ */
+ val = t_refi * freq_khz / 10000;
+ ref_ctrl_shdw |= val << REFRESH_RATE_SHIFT;
+
+ return ref_ctrl_shdw;
+}
+
+static u32 get_sdram_tim_1_shdw(const struct lpddr2_timings *timings,
+ const struct lpddr2_min_tck *min_tck,
+ const struct lpddr2_addressing *addressing)
+{
+ u32 tim1 = 0, val = 0;
+
+ val = max(min_tck->tWTR, DIV_ROUND_UP(timings->tWTR, t_ck)) - 1;
+ tim1 |= val << T_WTR_SHIFT;
+
+ if (addressing->num_banks == B8)
+ val = DIV_ROUND_UP(timings->tFAW, t_ck*4);
+ else
+ val = max(min_tck->tRRD, DIV_ROUND_UP(timings->tRRD, t_ck));
+ tim1 |= (val - 1) << T_RRD_SHIFT;
+
+ val = DIV_ROUND_UP(timings->tRAS_min + timings->tRPab, t_ck) - 1;
+ tim1 |= val << T_RC_SHIFT;
+
+ val = max(min_tck->tRASmin, DIV_ROUND_UP(timings->tRAS_min, t_ck));
+ tim1 |= (val - 1) << T_RAS_SHIFT;
+
+ val = max(min_tck->tWR, DIV_ROUND_UP(timings->tWR, t_ck)) - 1;
+ tim1 |= val << T_WR_SHIFT;
+
+ val = max(min_tck->tRCD, DIV_ROUND_UP(timings->tRCD, t_ck)) - 1;
+ tim1 |= val << T_RCD_SHIFT;
+
+ val = max(min_tck->tRPab, DIV_ROUND_UP(timings->tRPab, t_ck)) - 1;
+ tim1 |= val << T_RP_SHIFT;
+
+ return tim1;
+}
+
+static u32 get_sdram_tim_1_shdw_derated(const struct lpddr2_timings *timings,
+ const struct lpddr2_min_tck *min_tck,
+ const struct lpddr2_addressing *addressing)
+{
+ u32 tim1 = 0, val = 0;
+
+ val = max(min_tck->tWTR, DIV_ROUND_UP(timings->tWTR, t_ck)) - 1;
+ tim1 = val << T_WTR_SHIFT;
+
+ /*
+ * tFAW is approximately 4 times tRRD. So add 1875*4 = 7500ps
+ * to tFAW for de-rating
+ */
+ if (addressing->num_banks == B8) {
+ val = DIV_ROUND_UP(timings->tFAW + 7500, 4 * t_ck) - 1;
+ } else {
+ val = DIV_ROUND_UP(timings->tRRD + 1875, t_ck);
+ val = max(min_tck->tRRD, val) - 1;
+ }
+ tim1 |= val << T_RRD_SHIFT;
+
+ val = DIV_ROUND_UP(timings->tRAS_min + timings->tRPab + 1875, t_ck);
+ tim1 |= (val - 1) << T_RC_SHIFT;
+
+ val = DIV_ROUND_UP(timings->tRAS_min + 1875, t_ck);
+ val = max(min_tck->tRASmin, val) - 1;
+ tim1 |= val << T_RAS_SHIFT;
+
+ val = max(min_tck->tWR, DIV_ROUND_UP(timings->tWR, t_ck)) - 1;
+ tim1 |= val << T_WR_SHIFT;
+
+ val = max(min_tck->tRCD, DIV_ROUND_UP(timings->tRCD + 1875, t_ck));
+ tim1 |= (val - 1) << T_RCD_SHIFT;
+
+ val = max(min_tck->tRPab, DIV_ROUND_UP(timings->tRPab + 1875, t_ck));
+ tim1 |= (val - 1) << T_RP_SHIFT;
+
+ return tim1;
+}
+
+static u32 get_sdram_tim_2_shdw(const struct lpddr2_timings *timings,
+ const struct lpddr2_min_tck *min_tck,
+ const struct lpddr2_addressing *addressing,
+ u32 type)
+{
+ u32 tim2 = 0, val = 0;
+
+ val = min_tck->tCKE - 1;
+ tim2 |= val << T_CKE_SHIFT;
+
+ val = max(min_tck->tRTP, DIV_ROUND_UP(timings->tRTP, t_ck)) - 1;
+ tim2 |= val << T_RTP_SHIFT;
+
+ /* tXSNR = tRFCab_ps + 10 ns(tRFCab_ps for LPDDR2). */
+ val = DIV_ROUND_UP(addressing->tRFCab_ps + 10000, t_ck) - 1;
+ tim2 |= val << T_XSNR_SHIFT;
+
+ /* XSRD same as XSNR for LPDDR2 */
+ tim2 |= val << T_XSRD_SHIFT;
+
+ val = max(min_tck->tXP, DIV_ROUND_UP(timings->tXP, t_ck)) - 1;
+ tim2 |= val << T_XP_SHIFT;
+
+ return tim2;
+}
+
+static u32 get_sdram_tim_3_shdw(const struct lpddr2_timings *timings,
+ const struct lpddr2_min_tck *min_tck,
+ const struct lpddr2_addressing *addressing,
+ u32 type, u32 ip_rev, u32 derated)
+{
+ u32 tim3 = 0, val = 0, t_dqsck;
+
+ val = timings->tRAS_max_ns / addressing->tREFI_ns - 1;
+ val = val > 0xF ? 0xF : val;
+ tim3 |= val << T_RAS_MAX_SHIFT;
+
+ val = DIV_ROUND_UP(addressing->tRFCab_ps, t_ck) - 1;
+ tim3 |= val << T_RFC_SHIFT;
+
+ t_dqsck = (derated == EMIF_DERATED_TIMINGS) ?
+ timings->tDQSCK_max_derated : timings->tDQSCK_max;
+ if (ip_rev == EMIF_4D5)
+ val = DIV_ROUND_UP(t_dqsck + 1000, t_ck) - 1;
+ else
+ val = DIV_ROUND_UP(t_dqsck, t_ck) - 1;
+
+ tim3 |= val << T_TDQSCKMAX_SHIFT;
+
+ val = DIV_ROUND_UP(timings->tZQCS, t_ck) - 1;
+ tim3 |= val << ZQ_ZQCS_SHIFT;
+
+ val = DIV_ROUND_UP(timings->tCKESR, t_ck);
+ val = max(min_tck->tCKESR, val) - 1;
+ tim3 |= val << T_CKESR_SHIFT;
+
+ if (ip_rev == EMIF_4D5) {
+ tim3 |= (EMIF_T_CSTA - 1) << T_CSTA_SHIFT;
+
+ val = DIV_ROUND_UP(EMIF_T_PDLL_UL, 128) - 1;
+ tim3 |= val << T_PDLL_UL_SHIFT;
+ }
+
+ return tim3;
+}
+
+static u32 get_read_idle_ctrl_shdw(u8 volt_ramp)
+{
+ u32 idle = 0, val = 0;
+
+ /*
+ * Maximum value in normal conditions and increased frequency
+ * when voltage is ramping
+ */
+ if (volt_ramp)
+ val = READ_IDLE_INTERVAL_DVFS / t_ck / 64 - 1;
+ else
+ val = 0x1FF;
+
+ /*
+ * READ_IDLE_CTRL register in EMIF4D has same offset and fields
+ * as DLL_CALIB_CTRL in EMIF4D5, so use the same shifts
+ */
+ idle |= val << DLL_CALIB_INTERVAL_SHIFT;
+ idle |= EMIF_READ_IDLE_LEN_VAL << ACK_WAIT_SHIFT;
+
+ return idle;
+}
+
+static u32 get_dll_calib_ctrl_shdw(u8 volt_ramp)
+{
+ u32 calib = 0, val = 0;
+
+ if (volt_ramp == DDR_VOLTAGE_RAMPING)
+ val = DLL_CALIB_INTERVAL_DVFS / t_ck / 16 - 1;
+ else
+ val = 0; /* Disabled when voltage is stable */
+
+ calib |= val << DLL_CALIB_INTERVAL_SHIFT;
+ calib |= DLL_CALIB_ACK_WAIT_VAL << ACK_WAIT_SHIFT;
+
+ return calib;
+}
+
+static u32 get_ddr_phy_ctrl_1_attilaphy_4d(const struct lpddr2_timings *timings,
+ u32 freq, u8 RL)
+{
+ u32 phy = EMIF_DDR_PHY_CTRL_1_BASE_VAL_ATTILAPHY, val = 0;
+
+ val = RL + DIV_ROUND_UP(timings->tDQSCK_max, t_ck) - 1;
+ phy |= val << READ_LATENCY_SHIFT_4D;
+
+ if (freq <= 100000000)
+ val = EMIF_DLL_SLAVE_DLY_CTRL_100_MHZ_AND_LESS_ATTILAPHY;
+ else if (freq <= 200000000)
+ val = EMIF_DLL_SLAVE_DLY_CTRL_200_MHZ_ATTILAPHY;
+ else
+ val = EMIF_DLL_SLAVE_DLY_CTRL_400_MHZ_ATTILAPHY;
+
+ phy |= val << DLL_SLAVE_DLY_CTRL_SHIFT_4D;
+
+ return phy;
+}
+
+static u32 get_phy_ctrl_1_intelliphy_4d5(u32 freq, u8 cl)
+{
+ u32 phy = EMIF_DDR_PHY_CTRL_1_BASE_VAL_INTELLIPHY, half_delay;
+
+ /*
+ * DLL operates at 266 MHz. If DDR frequency is near 266 MHz,
+ * half-delay is not needed else set half-delay
+ */
+ if (freq >= 265000000 && freq < 267000000)
+ half_delay = 0;
+ else
+ half_delay = 1;
+
+ phy |= half_delay << DLL_HALF_DELAY_SHIFT_4D5;
+ phy |= ((cl + DIV_ROUND_UP(EMIF_PHY_TOTAL_READ_LATENCY_INTELLIPHY_PS,
+ t_ck) - 1) << READ_LATENCY_SHIFT_4D5);
+
+ return phy;
+}
+
+static u32 get_ext_phy_ctrl_2_intelliphy_4d5(void)
+{
+ u32 fifo_we_slave_ratio;
+
+ fifo_we_slave_ratio = DIV_ROUND_CLOSEST(
+ EMIF_INTELLI_PHY_DQS_GATE_OPENING_DELAY_PS * 256 , t_ck);
+
+ return fifo_we_slave_ratio | fifo_we_slave_ratio << 11 |
+ fifo_we_slave_ratio << 22;
+}
+
+static u32 get_ext_phy_ctrl_3_intelliphy_4d5(void)
+{
+ u32 fifo_we_slave_ratio;
+
+ fifo_we_slave_ratio = DIV_ROUND_CLOSEST(
+ EMIF_INTELLI_PHY_DQS_GATE_OPENING_DELAY_PS * 256 , t_ck);
+
+ return fifo_we_slave_ratio >> 10 | fifo_we_slave_ratio << 1 |
+ fifo_we_slave_ratio << 12 | fifo_we_slave_ratio << 23;
+}
+
+static u32 get_ext_phy_ctrl_4_intelliphy_4d5(void)
+{
+ u32 fifo_we_slave_ratio;
+
+ fifo_we_slave_ratio = DIV_ROUND_CLOSEST(
+ EMIF_INTELLI_PHY_DQS_GATE_OPENING_DELAY_PS * 256 , t_ck);
+
+ return fifo_we_slave_ratio >> 9 | fifo_we_slave_ratio << 2 |
+ fifo_we_slave_ratio << 13;
+}
+
+static u32 get_pwr_mgmt_ctrl(u32 freq, struct emif_data *emif, u32 ip_rev)
+{
+ u32 pwr_mgmt_ctrl = 0, timeout;
+ u32 lpmode = EMIF_LP_MODE_SELF_REFRESH;
+ u32 timeout_perf = EMIF_LP_MODE_TIMEOUT_PERFORMANCE;
+ u32 timeout_pwr = EMIF_LP_MODE_TIMEOUT_POWER;
+ u32 freq_threshold = EMIF_LP_MODE_FREQ_THRESHOLD;
+
+ struct emif_custom_configs *cust_cfgs = emif->plat_data->custom_configs;
+
+ if (cust_cfgs && (cust_cfgs->mask & EMIF_CUSTOM_CONFIG_LPMODE)) {
+ lpmode = cust_cfgs->lpmode;
+ timeout_perf = cust_cfgs->lpmode_timeout_performance;
+ timeout_pwr = cust_cfgs->lpmode_timeout_power;
+ freq_threshold = cust_cfgs->lpmode_freq_threshold;
+ }
+
+ /* Timeout based on DDR frequency */
+ timeout = freq >= freq_threshold ? timeout_perf : timeout_pwr;
+
+ /* The value to be set in register is "log2(timeout) - 3" */
+ if (timeout < 16) {
+ timeout = 0;
+ } else {
+ timeout = __fls(timeout) - 3;
+ if (timeout & (timeout - 1))
+ timeout++;
+ }
+
+ switch (lpmode) {
+ case EMIF_LP_MODE_CLOCK_STOP:
+ pwr_mgmt_ctrl = (timeout << CS_TIM_SHIFT) |
+ SR_TIM_MASK | PD_TIM_MASK;
+ break;
+ case EMIF_LP_MODE_SELF_REFRESH:
+ /* Workaround for errata i735 */
+ if (timeout < 6)
+ timeout = 6;
+
+ pwr_mgmt_ctrl = (timeout << SR_TIM_SHIFT) |
+ CS_TIM_MASK | PD_TIM_MASK;
+ break;
+ case EMIF_LP_MODE_PWR_DN:
+ pwr_mgmt_ctrl = (timeout << PD_TIM_SHIFT) |
+ CS_TIM_MASK | SR_TIM_MASK;
+ break;
+ case EMIF_LP_MODE_DISABLE:
+ default:
+ pwr_mgmt_ctrl = CS_TIM_MASK |
+ PD_TIM_MASK | SR_TIM_MASK;
+ }
+
+ /* No CS_TIM in EMIF_4D5 */
+ if (ip_rev == EMIF_4D5)
+ pwr_mgmt_ctrl &= ~CS_TIM_MASK;
+
+ pwr_mgmt_ctrl |= lpmode << LP_MODE_SHIFT;
+
+ return pwr_mgmt_ctrl;
+}
+
+/*
+ * Program EMIF shadow registers that are not dependent on temperature
+ * or voltage
+ */
+static void setup_registers(struct emif_data *emif, struct emif_regs *regs)
+{
+ void __iomem *base = emif->base;
+
+ writel(regs->sdram_tim2_shdw, base + EMIF_SDRAM_TIMING_2_SHDW);
+ writel(regs->phy_ctrl_1_shdw, base + EMIF_DDR_PHY_CTRL_1_SHDW);
+
+ /* Settings specific for EMIF4D5 */
+ if (emif->plat_data->ip_rev != EMIF_4D5)
+ return;
+ writel(regs->ext_phy_ctrl_2_shdw, base + EMIF_EXT_PHY_CTRL_2_SHDW);
+ writel(regs->ext_phy_ctrl_3_shdw, base + EMIF_EXT_PHY_CTRL_3_SHDW);
+ writel(regs->ext_phy_ctrl_4_shdw, base + EMIF_EXT_PHY_CTRL_4_SHDW);
+}
+
+/*
+ * When voltage ramps dll calibration and forced read idle should
+ * happen more often
+ */
+static void setup_volt_sensitive_regs(struct emif_data *emif,
+ struct emif_regs *regs, u32 volt_state)
+{
+ u32 calib_ctrl;
+ void __iomem *base = emif->base;
+
+ /*
+ * EMIF_READ_IDLE_CTRL in EMIF4D refers to the same register as
+ * EMIF_DLL_CALIB_CTRL in EMIF4D5 and dll_calib_ctrl_shadow_*
+ * is an alias of the respective read_idle_ctrl_shdw_* (members of
+ * a union). So, the below code takes care of both cases
+ */
+ if (volt_state == DDR_VOLTAGE_RAMPING)
+ calib_ctrl = regs->dll_calib_ctrl_shdw_volt_ramp;
+ else
+ calib_ctrl = regs->dll_calib_ctrl_shdw_normal;
+
+ writel(calib_ctrl, base + EMIF_DLL_CALIB_CTRL_SHDW);
+}
+
+/*
+ * setup_temperature_sensitive_regs() - set the timings for temperature
+ * sensitive registers. This happens once at initialisation time based
+ * on the temperature at boot time and subsequently based on the temperature
+ * alert interrupt. Temperature alert can happen when the temperature
+ * increases or drops. So this function can have the effect of either
+ * derating the timings or going back to nominal values.
+ */
+static void setup_temperature_sensitive_regs(struct emif_data *emif,
+ struct emif_regs *regs)
+{
+ u32 tim1, tim3, ref_ctrl, type;
+ void __iomem *base = emif->base;
+ u32 temperature;
+
+ type = emif->plat_data->device_info->type;
+
+ tim1 = regs->sdram_tim1_shdw;
+ tim3 = regs->sdram_tim3_shdw;
+ ref_ctrl = regs->ref_ctrl_shdw;
+
+ /* No de-rating for non-lpddr2 devices */
+ if (type != DDR_TYPE_LPDDR2_S2 && type != DDR_TYPE_LPDDR2_S4)
+ goto out;
+
+ temperature = emif->temperature_level;
+ if (temperature == SDRAM_TEMP_HIGH_DERATE_REFRESH) {
+ ref_ctrl = regs->ref_ctrl_shdw_derated;
+ } else if (temperature == SDRAM_TEMP_HIGH_DERATE_REFRESH_AND_TIMINGS) {
+ tim1 = regs->sdram_tim1_shdw_derated;
+ tim3 = regs->sdram_tim3_shdw_derated;
+ ref_ctrl = regs->ref_ctrl_shdw_derated;
+ }
+
+out:
+ writel(tim1, base + EMIF_SDRAM_TIMING_1_SHDW);
+ writel(tim3, base + EMIF_SDRAM_TIMING_3_SHDW);
+ writel(ref_ctrl, base + EMIF_SDRAM_REFRESH_CTRL_SHDW);
+}
+
static void get_default_timings(struct emif_data *emif)
{
struct emif_platform_data *pd = emif->plat_data;
@@ -234,10 +810,8 @@ static int __init_or_module emif_probe(struct platform_device *pdev)
goto error;
}
- if (!emif1)
- emif1 = emif;
-
list_add(&emif->node, &device_list);
+ emif->addressing = get_addressing_table(emif->plat_data->device_info);
/* Save pointers to each other in emif and device structures */
emif->dev = &pdev->dev;
@@ -257,6 +831,18 @@ static int __init_or_module emif_probe(struct platform_device *pdev)
goto error;
}
+ /* One-time actions taken on probing the first device */
+ if (!emif1) {
+ emif1 = emif;
+ spin_lock_init(&emif_lock);
+
+ /*
+ * TODO: register notifiers for frequency and voltage
+ * change here once the respective frameworks are
+ * available
+ */
+ }
+
dev_info(&pdev->dev, "%s: device configured with addr = %p\n",
__func__, emif->base);
@@ -265,6 +851,308 @@ error:
return -ENODEV;
}
+static int get_emif_reg_values(struct emif_data *emif, u32 freq,
+ struct emif_regs *regs)
+{
+ u32 cs1_used, ip_rev, phy_type;
+ u32 cl, type;
+ const struct lpddr2_timings *timings;
+ const struct lpddr2_min_tck *min_tck;
+ const struct ddr_device_info *device_info;
+ const struct lpddr2_addressing *addressing;
+ struct emif_data *emif_for_calc;
+ struct device *dev;
+ const struct emif_custom_configs *custom_configs;
+
+ dev = emif->dev;
+ /*
+ * If the devices on this EMIF instance is duplicate of EMIF1,
+ * use EMIF1 details for the calculation
+ */
+ emif_for_calc = emif->duplicate ? emif1 : emif;
+ timings = get_timings_table(emif_for_calc, freq);
+ addressing = emif_for_calc->addressing;
+ if (!timings || !addressing) {
+ dev_err(dev, "%s: not enough data available for %dHz",
+ __func__, freq);
+ return -1;
+ }
+
+ device_info = emif_for_calc->plat_data->device_info;
+ type = device_info->type;
+ cs1_used = device_info->cs1_used;
+ ip_rev = emif_for_calc->plat_data->ip_rev;
+ phy_type = emif_for_calc->plat_data->phy_type;
+
+ min_tck = emif_for_calc->plat_data->min_tck;
+ custom_configs = emif_for_calc->plat_data->custom_configs;
+
+ set_ddr_clk_period(freq);
+
+ regs->ref_ctrl_shdw = get_sdram_ref_ctrl_shdw(freq, addressing);
+ regs->sdram_tim1_shdw = get_sdram_tim_1_shdw(timings, min_tck,
+ addressing);
+ regs->sdram_tim2_shdw = get_sdram_tim_2_shdw(timings, min_tck,
+ addressing, type);
+ regs->sdram_tim3_shdw = get_sdram_tim_3_shdw(timings, min_tck,
+ addressing, type, ip_rev, EMIF_NORMAL_TIMINGS);
+
+ cl = get_cl(emif);
+
+ if (phy_type == EMIF_PHY_TYPE_ATTILAPHY && ip_rev == EMIF_4D) {
+ regs->phy_ctrl_1_shdw = get_ddr_phy_ctrl_1_attilaphy_4d(
+ timings, freq, cl);
+ } else if (phy_type == EMIF_PHY_TYPE_INTELLIPHY && ip_rev == EMIF_4D5) {
+ regs->phy_ctrl_1_shdw = get_phy_ctrl_1_intelliphy_4d5(freq, cl);
+ regs->ext_phy_ctrl_2_shdw = get_ext_phy_ctrl_2_intelliphy_4d5();
+ regs->ext_phy_ctrl_3_shdw = get_ext_phy_ctrl_3_intelliphy_4d5();
+ regs->ext_phy_ctrl_4_shdw = get_ext_phy_ctrl_4_intelliphy_4d5();
+ } else {
+ return -1;
+ }
+
+ /* Only timeout values in pwr_mgmt_ctrl_shdw register */
+ regs->pwr_mgmt_ctrl_shdw =
+ get_pwr_mgmt_ctrl(freq, emif_for_calc, ip_rev) &
+ (CS_TIM_MASK | SR_TIM_MASK | PD_TIM_MASK);
+
+ if (ip_rev & EMIF_4D) {
+ regs->read_idle_ctrl_shdw_normal =
+ get_read_idle_ctrl_shdw(DDR_VOLTAGE_STABLE);
+
+ regs->read_idle_ctrl_shdw_volt_ramp =
+ get_read_idle_ctrl_shdw(DDR_VOLTAGE_RAMPING);
+ } else if (ip_rev & EMIF_4D5) {
+ regs->dll_calib_ctrl_shdw_normal =
+ get_dll_calib_ctrl_shdw(DDR_VOLTAGE_STABLE);
+
+ regs->dll_calib_ctrl_shdw_volt_ramp =
+ get_dll_calib_ctrl_shdw(DDR_VOLTAGE_RAMPING);
+ }
+
+ if (type == DDR_TYPE_LPDDR2_S2 || type == DDR_TYPE_LPDDR2_S4) {
+ regs->ref_ctrl_shdw_derated = get_sdram_ref_ctrl_shdw(freq / 4,
+ addressing);
+
+ regs->sdram_tim1_shdw_derated =
+ get_sdram_tim_1_shdw_derated(timings, min_tck,
+ addressing);
+
+ regs->sdram_tim3_shdw_derated = get_sdram_tim_3_shdw(timings,
+ min_tck, addressing, type, ip_rev,
+ EMIF_DERATED_TIMINGS);
+ }
+
+ regs->freq = freq;
+
+ return 0;
+}
+
+/*
+ * get_regs() - gets the cached emif_regs structure for a given EMIF instance
+ * given frequency(freq):
+ *
+ * As an optimisation, every EMIF instance other than EMIF1 shares the
+ * register cache with EMIF1 if the devices connected on this instance
+ * are same as that on EMIF1(indicated by the duplicate flag)
+ *
+ * If we do not have an entry corresponding to the frequency given, we
+ * allocate a new entry and calculate the values
+ *
+ * Upon finding the right reg dump, save it in curr_regs. It can be
+ * directly used for thermal de-rating and voltage ramping changes.
+ */
+static struct emif_regs *get_regs(struct emif_data *emif, u32 freq)
+{
+ int i;
+ struct emif_regs **regs_cache;
+ struct emif_regs *regs = NULL;
+ struct device *dev;
+
+ dev = emif->dev;
+ if (emif->curr_regs && emif->curr_regs->freq == freq) {
+ dev_dbg(dev, "%s: using curr_regs - %u Hz", __func__, freq);
+ return emif->curr_regs;
+ }
+
+ if (emif->duplicate)
+ regs_cache = emif1->regs_cache;
+ else
+ regs_cache = emif->regs_cache;
+
+ for (i = 0; i < EMIF_MAX_NUM_FREQUENCIES && regs_cache[i]; i++) {
+ if (regs_cache[i]->freq == freq) {
+ regs = regs_cache[i];
+ dev_dbg(dev,
+ "%s: reg dump found in reg cache for %u Hz\n",
+ __func__, freq);
+ break;
+ }
+ }
+
+ /*
+ * If we don't have an entry for this frequency in the cache create one
+ * and calculate the values
+ */
+ if (!regs) {
+ regs = devm_kzalloc(emif->dev, sizeof(*regs), GFP_ATOMIC);
+ if (!regs)
+ return NULL;
+
+ if (get_emif_reg_values(emif, freq, regs)) {
+ devm_kfree(emif->dev, regs);
+ return NULL;
+ }
+
+ /*
+ * Now look for an un-used entry in the cache and save the
+ * newly created struct. If there are no free entries
+ * over-write the last entry
+ */
+ for (i = 0; i < EMIF_MAX_NUM_FREQUENCIES && regs_cache[i]; i++)
+ ;
+
+ if (i >= EMIF_MAX_NUM_FREQUENCIES) {
+ dev_warn(dev, "%s: regs_cache full - reusing a slot!!\n",
+ __func__);
+ i = EMIF_MAX_NUM_FREQUENCIES - 1;
+ devm_kfree(emif->dev, regs_cache[i]);
+ }
+ regs_cache[i] = regs;
+ }
+
+ return regs;
+}
+
+static void do_volt_notify_handling(struct emif_data *emif, u32 volt_state)
+{
+ dev_dbg(emif->dev, "%s: voltage notification : %d", __func__,
+ volt_state);
+
+ if (!emif->curr_regs) {
+ dev_err(emif->dev,
+ "%s: volt-notify before registers are ready: %d\n",
+ __func__, volt_state);
+ return;
+ }
+
+ setup_volt_sensitive_regs(emif, emif->curr_regs, volt_state);
+}
+
+/*
+ * TODO: voltage notify handling should be hooked up to
+ * regulator framework as soon as the necessary support
+ * is available in mainline kernel. This function is un-used
+ * right now.
+ */
+static void __attribute__((unused)) volt_notify_handling(u32 volt_state)
+{
+ struct emif_data *emif;
+
+ spin_lock_irqsave(&emif_lock, irq_state);
+
+ list_for_each_entry(emif, &device_list, node)
+ do_volt_notify_handling(emif, volt_state);
+ do_freq_update();
+
+ spin_unlock_irqrestore(&emif_lock, irq_state);
+}
+
+static void do_freq_pre_notify_handling(struct emif_data *emif, u32 new_freq)
+{
+ struct emif_regs *regs;
+
+ regs = get_regs(emif, new_freq);
+ if (!regs)
+ return;
+
+ emif->curr_regs = regs;
+
+ /*
+ * Update the shadow registers:
+ * Temperature and voltage-ramp sensitive settings are also configured
+ * in terms of DDR cycles. So, we need to update them too when there
+ * is a freq change
+ */
+ dev_dbg(emif->dev, "%s: setting up shadow registers for %uHz",
+ __func__, new_freq);
+ setup_registers(emif, regs);
+ setup_temperature_sensitive_regs(emif, regs);
+ setup_volt_sensitive_regs(emif, regs, DDR_VOLTAGE_STABLE);
+
+ /*
+ * Part of workaround for errata i728. See do_freq_update()
+ * for more details
+ */
+ if (emif->lpmode == EMIF_LP_MODE_SELF_REFRESH)
+ set_lpmode(emif, EMIF_LP_MODE_DISABLE);
+}
+
+/*
+ * TODO: frequency notify handling should be hooked up to
+ * clock framework as soon as the necessary support is
+ * available in mainline kernel. This function is un-used
+ * right now.
+ */
+static void __attribute__((unused)) freq_pre_notify_handling(u32 new_freq)
+{
+ struct emif_data *emif;
+
+ /*
+ * NOTE: we are taking the spin-lock here and releases it
+ * only in post-notifier. This doesn't look good and
+ * Sparse complains about it, but this seems to be
+ * un-avoidable. We need to lock a sequence of events
+ * that is split between EMIF and clock framework.
+ *
+ * 1. EMIF driver updates EMIF timings in shadow registers in the
+ * frequency pre-notify callback from clock framework
+ * 2. clock framework sets up the registers for the new frequency
+ * 3. clock framework initiates a hw-sequence that updates
+ * the frequency EMIF timings synchronously.
+ *
+ * All these 3 steps should be performed as an atomic operation
+ * vis-a-vis similar sequence in the EMIF interrupt handler
+ * for temperature events. Otherwise, there could be race
+ * conditions that could result in incorrect EMIF timings for
+ * a given frequency
+ */
+ spin_lock_irqsave(&emif_lock, irq_state);
+
+ list_for_each_entry(emif, &device_list, node)
+ do_freq_pre_notify_handling(emif, new_freq);
+}
+
+static void do_freq_post_notify_handling(struct emif_data *emif)
+{
+ /*
+ * Part of workaround for errata i728. See do_freq_update()
+ * for more details
+ */
+ if (emif->lpmode == EMIF_LP_MODE_SELF_REFRESH)
+ set_lpmode(emif, EMIF_LP_MODE_SELF_REFRESH);
+}
+
+/*
+ * TODO: frequency notify handling should be hooked up to
+ * clock framework as soon as the necessary support is
+ * available in mainline kernel. This function is un-used
+ * right now.
+ */
+static void __attribute__((unused)) freq_post_notify_handling(void)
+{
+ struct emif_data *emif;
+
+ list_for_each_entry(emif, &device_list, node)
+ do_freq_post_notify_handling(emif);
+
+ /*
+ * Lock is done in pre-notify handler. See freq_pre_notify_handling()
+ * for more details
+ */
+ spin_unlock_irqrestore(&emif_lock, irq_state);
+}
+
static struct platform_driver emif_driver = {
.driver = {
.name = "emif",
diff --git a/drivers/misc/emif.h b/drivers/misc/emif.h
index 692b2a8..bfe08ba 100644
--- a/drivers/misc/emif.h
+++ b/drivers/misc/emif.h
@@ -19,6 +19,103 @@
*/
#define EMIF_MAX_NUM_FREQUENCIES 6
+/* State of the core voltage */
+#define DDR_VOLTAGE_STABLE 0
+#define DDR_VOLTAGE_RAMPING 1
+
+/* Defines for timing De-rating */
+#define EMIF_NORMAL_TIMINGS 0
+#define EMIF_DERATED_TIMINGS 1
+
+/* Length of the forced read idle period in terms of cycles */
+#define EMIF_READ_IDLE_LEN_VAL 5
+
+/*
+ * forced read idle interval to be used when voltage
+ * is changed as part of DVFS/DPS - 1ms
+ */
+#define READ_IDLE_INTERVAL_DVFS (1*1000000)
+
+/*
+ * Forced read idle interval to be used when voltage is stable
+ * 50us - or maximum value will do
+ */
+#define READ_IDLE_INTERVAL_NORMAL (50*1000000)
+
+/* DLL calibration interval when voltage is NOT stable - 1us */
+#define DLL_CALIB_INTERVAL_DVFS (1*1000000)
+
+#define DLL_CALIB_ACK_WAIT_VAL 5
+
+/* Interval between ZQCS commands - hw team recommended value */
+#define EMIF_ZQCS_INTERVAL_US (50*1000)
+/* Enable ZQ Calibration on exiting Self-refresh */
+#define ZQ_SFEXITEN_ENABLE 1
+/*
+ * ZQ Calibration simultaneously on both chip-selects:
+ * Needs one calibration resistor per CS
+ */
+#define ZQ_DUALCALEN_DISABLE 0
+#define ZQ_DUALCALEN_ENABLE 1
+
+#define T_ZQCS_DEFAULT_NS 90
+#define T_ZQCL_DEFAULT_NS 360
+#define T_ZQINIT_DEFAULT_NS 1000
+
+/* DPD_EN */
+#define DPD_DISABLE 0
+#define DPD_ENABLE 1
+
+/*
+ * Default values for the low-power entry to be used if not provided by user.
+ * OMAP4/5 has a hw bug(i735) due to which this value can not be less than 512
+ * Timeout values are in DDR clock 'cycles' and frequency threshold in Hz
+ */
+#define EMIF_LP_MODE_TIMEOUT_PERFORMANCE 2048
+#define EMIF_LP_MODE_TIMEOUT_POWER 512
+#define EMIF_LP_MODE_FREQ_THRESHOLD 400000000
+
+/* DDR_PHY_CTRL_1 values for EMIF4D - ATTILA PHY combination */
+#define EMIF_DDR_PHY_CTRL_1_BASE_VAL_ATTILAPHY 0x049FF000
+#define EMIF_DLL_SLAVE_DLY_CTRL_400_MHZ_ATTILAPHY 0x41
+#define EMIF_DLL_SLAVE_DLY_CTRL_200_MHZ_ATTILAPHY 0x80
+#define EMIF_DLL_SLAVE_DLY_CTRL_100_MHZ_AND_LESS_ATTILAPHY 0xFF
+
+/* DDR_PHY_CTRL_1 values for EMIF4D5 INTELLIPHY combination */
+#define EMIF_DDR_PHY_CTRL_1_BASE_VAL_INTELLIPHY 0x0E084200
+#define EMIF_PHY_TOTAL_READ_LATENCY_INTELLIPHY_PS 10000
+
+/* TEMP_ALERT_CONFIG - corresponding to temp gradient 5 C/s */
+#define TEMP_ALERT_POLL_INTERVAL_DEFAULT_MS 360
+
+#define EMIF_T_CSTA 3
+#define EMIF_T_PDLL_UL 128
+
+/* External PHY control registers magic values */
+#define EMIF_EXT_PHY_CTRL_1_VAL 0x04020080
+#define EMIF_EXT_PHY_CTRL_5_VAL 0x04010040
+#define EMIF_EXT_PHY_CTRL_6_VAL 0x01004010
+#define EMIF_EXT_PHY_CTRL_7_VAL 0x00001004
+#define EMIF_EXT_PHY_CTRL_8_VAL 0x04010040
+#define EMIF_EXT_PHY_CTRL_9_VAL 0x01004010
+#define EMIF_EXT_PHY_CTRL_10_VAL 0x00001004
+#define EMIF_EXT_PHY_CTRL_11_VAL 0x00000000
+#define EMIF_EXT_PHY_CTRL_12_VAL 0x00000000
+#define EMIF_EXT_PHY_CTRL_13_VAL 0x00000000
+#define EMIF_EXT_PHY_CTRL_14_VAL 0x80080080
+#define EMIF_EXT_PHY_CTRL_15_VAL 0x00800800
+#define EMIF_EXT_PHY_CTRL_16_VAL 0x08102040
+#define EMIF_EXT_PHY_CTRL_17_VAL 0x00000001
+#define EMIF_EXT_PHY_CTRL_18_VAL 0x540A8150
+#define EMIF_EXT_PHY_CTRL_19_VAL 0xA81502A0
+#define EMIF_EXT_PHY_CTRL_20_VAL 0x002A0540
+#define EMIF_EXT_PHY_CTRL_21_VAL 0x00000000
+#define EMIF_EXT_PHY_CTRL_22_VAL 0x00000000
+#define EMIF_EXT_PHY_CTRL_23_VAL 0x00000000
+#define EMIF_EXT_PHY_CTRL_24_VAL 0x00000077
+
+#define EMIF_INTELLI_PHY_DQS_GATE_OPENING_DELAY_PS 1200
+
/* Registers offset */
#define EMIF_MODULE_ID_AND_REVISION 0x0000
#define EMIF_STATUS 0x0004
@@ -458,4 +555,35 @@
#define READ_LATENCY_SHDW_SHIFT 0
#define READ_LATENCY_SHDW_MASK (0x1f << 0)
-#endif
+#ifndef __ASSEMBLY__
+/*
+ * Structure containing shadow of important registers in EMIF
+ * The calculation function fills in this structure to be later used for
+ * initialisation and DVFS
+ */
+struct emif_regs {
+ u32 freq;
+ u32 ref_ctrl_shdw;
+ u32 ref_ctrl_shdw_derated;
+ u32 sdram_tim1_shdw;
+ u32 sdram_tim1_shdw_derated;
+ u32 sdram_tim2_shdw;
+ u32 sdram_tim3_shdw;
+ u32 sdram_tim3_shdw_derated;
+ u32 pwr_mgmt_ctrl_shdw;
+ union {
+ u32 read_idle_ctrl_shdw_normal;
+ u32 dll_calib_ctrl_shdw_normal;
+ };
+ union {
+ u32 read_idle_ctrl_shdw_volt_ramp;
+ u32 dll_calib_ctrl_shdw_volt_ramp;
+ };
+
+ u32 phy_ctrl_1_shdw;
+ u32 ext_phy_ctrl_2_shdw;
+ u32 ext_phy_ctrl_3_shdw;
+ u32 ext_phy_ctrl_4_shdw;
+};
+#endif /* __ASSEMBLY__ */
+#endif /* __EMIF_H */
--
1.7.1
--
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