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-rw-r--r--drivers/memory/tegra/tegra30-emc.c150
1 files changed, 89 insertions, 61 deletions
diff --git a/drivers/memory/tegra/tegra30-emc.c b/drivers/memory/tegra/tegra30-emc.c
index b86ae0c38ced..6f7bc9017c9a 100644
--- a/drivers/memory/tegra/tegra30-emc.c
+++ b/drivers/memory/tegra/tegra30-emc.c
@@ -332,7 +332,9 @@ struct tegra_emc {
struct clk *clk;
void __iomem *regs;
unsigned int irq;
+ bool bad_state;
+ struct emc_timing *new_timing;
struct emc_timing *timings;
unsigned int num_timings;
@@ -346,7 +348,6 @@ struct tegra_emc {
bool vref_cal_toggle : 1;
bool zcal_long : 1;
bool dll_on : 1;
- bool bad_state : 1;
struct {
struct dentry *root;
@@ -355,6 +356,66 @@ struct tegra_emc {
} debugfs;
};
+static int emc_seq_update_timing(struct tegra_emc *emc)
+{
+ u32 val;
+ int err;
+
+ writel_relaxed(EMC_TIMING_UPDATE, emc->regs + EMC_TIMING_CONTROL);
+
+ err = readl_relaxed_poll_timeout_atomic(emc->regs + EMC_STATUS, val,
+ !(val & EMC_STATUS_TIMING_UPDATE_STALLED),
+ 1, 200);
+ if (err) {
+ dev_err(emc->dev, "failed to update timing: %d\n", err);
+ return err;
+ }
+
+ return 0;
+}
+
+static void emc_complete_clk_change(struct tegra_emc *emc)
+{
+ struct emc_timing *timing = emc->new_timing;
+ unsigned int dram_num;
+ bool failed = false;
+ int err;
+
+ /* re-enable auto-refresh */
+ dram_num = tegra_mc_get_emem_device_count(emc->mc);
+ writel_relaxed(EMC_REFCTRL_ENABLE_ALL(dram_num),
+ emc->regs + EMC_REFCTRL);
+
+ /* restore auto-calibration */
+ if (emc->vref_cal_toggle)
+ writel_relaxed(timing->emc_auto_cal_interval,
+ emc->regs + EMC_AUTO_CAL_INTERVAL);
+
+ /* restore dynamic self-refresh */
+ if (timing->emc_cfg_dyn_self_ref) {
+ emc->emc_cfg |= EMC_CFG_DYN_SREF_ENABLE;
+ writel_relaxed(emc->emc_cfg, emc->regs + EMC_CFG);
+ }
+
+ /* set number of clocks to wait after each ZQ command */
+ if (emc->zcal_long)
+ writel_relaxed(timing->emc_zcal_cnt_long,
+ emc->regs + EMC_ZCAL_WAIT_CNT);
+
+ /* wait for writes to settle */
+ udelay(2);
+
+ /* update restored timing */
+ err = emc_seq_update_timing(emc);
+ if (err)
+ failed = true;
+
+ /* restore early ACK */
+ mc_writel(emc->mc, emc->mc_override, MC_EMEM_ARB_OVERRIDE);
+
+ WRITE_ONCE(emc->bad_state, failed);
+}
+
static irqreturn_t tegra_emc_isr(int irq, void *data)
{
struct tegra_emc *emc = data;
@@ -365,10 +426,6 @@ static irqreturn_t tegra_emc_isr(int irq, void *data)
if (!status)
return IRQ_NONE;
- /* notify about EMC-CAR handshake completion */
- if (status & EMC_CLKCHANGE_COMPLETE_INT)
- complete(&emc->clk_handshake_complete);
-
/* notify about HW problem */
if (status & EMC_REFRESH_OVERFLOW_INT)
dev_err_ratelimited(emc->dev,
@@ -377,6 +434,18 @@ static irqreturn_t tegra_emc_isr(int irq, void *data)
/* clear interrupts */
writel_relaxed(status, emc->regs + EMC_INTSTATUS);
+ /* notify about EMC-CAR handshake completion */
+ if (status & EMC_CLKCHANGE_COMPLETE_INT) {
+ if (completion_done(&emc->clk_handshake_complete)) {
+ dev_err_ratelimited(emc->dev,
+ "bogus handshake interrupt\n");
+ return IRQ_NONE;
+ }
+
+ emc_complete_clk_change(emc);
+ complete(&emc->clk_handshake_complete);
+ }
+
return IRQ_HANDLED;
}
@@ -444,24 +513,6 @@ static bool emc_dqs_preset(struct tegra_emc *emc, struct emc_timing *timing,
return preset;
}
-static int emc_seq_update_timing(struct tegra_emc *emc)
-{
- u32 val;
- int err;
-
- writel_relaxed(EMC_TIMING_UPDATE, emc->regs + EMC_TIMING_CONTROL);
-
- err = readl_relaxed_poll_timeout_atomic(emc->regs + EMC_STATUS, val,
- !(val & EMC_STATUS_TIMING_UPDATE_STALLED),
- 1, 200);
- if (err) {
- dev_err(emc->dev, "failed to update timing: %d\n", err);
- return err;
- }
-
- return 0;
-}
-
static int emc_prepare_mc_clk_cfg(struct tegra_emc *emc, unsigned long rate)
{
struct tegra_mc *mc = emc->mc;
@@ -627,9 +678,6 @@ static int emc_prepare_timing_change(struct tegra_emc *emc, unsigned long rate)
writel_relaxed(val, emc->regs + EMC_MRS_WAIT_CNT);
}
- /* disable interrupt since read access is prohibited after stalling */
- disable_irq(emc->irq);
-
/* this read also completes the writes */
val = readl_relaxed(emc->regs + EMC_SEL_DPD_CTRL);
@@ -745,17 +793,18 @@ static int emc_prepare_timing_change(struct tegra_emc *emc, unsigned long rate)
emc->regs + EMC_ZQ_CAL);
}
- /* re-enable auto-refresh */
- writel_relaxed(EMC_REFCTRL_ENABLE_ALL(dram_num),
- emc->regs + EMC_REFCTRL);
-
/* flow control marker 3 */
writel_relaxed(0x1, emc->regs + EMC_UNSTALL_RW_AFTER_CLKCHANGE);
+ /*
+ * Read and discard an arbitrary MC register (Note: EMC registers
+ * can't be used) to ensure the register writes are completed.
+ */
+ mc_readl(emc->mc, MC_EMEM_ARB_OVERRIDE);
+
reinit_completion(&emc->clk_handshake_complete);
- /* interrupt can be re-enabled now */
- enable_irq(emc->irq);
+ emc->new_timing = timing;
return 0;
}
@@ -763,9 +812,7 @@ static int emc_prepare_timing_change(struct tegra_emc *emc, unsigned long rate)
static int emc_complete_timing_change(struct tegra_emc *emc,
unsigned long rate)
{
- struct emc_timing *timing = emc_find_timing(emc, rate);
unsigned long timeout;
- int err;
timeout = wait_for_completion_timeout(&emc->clk_handshake_complete,
msecs_to_jiffies(100));
@@ -774,33 +821,8 @@ static int emc_complete_timing_change(struct tegra_emc *emc,
return -EIO;
}
- /* restore auto-calibration */
- if (emc->vref_cal_toggle)
- writel_relaxed(timing->emc_auto_cal_interval,
- emc->regs + EMC_AUTO_CAL_INTERVAL);
-
- /* restore dynamic self-refresh */
- if (timing->emc_cfg_dyn_self_ref) {
- emc->emc_cfg |= EMC_CFG_DYN_SREF_ENABLE;
- writel_relaxed(emc->emc_cfg, emc->regs + EMC_CFG);
- }
-
- /* set number of clocks to wait after each ZQ command */
- if (emc->zcal_long)
- writel_relaxed(timing->emc_zcal_cnt_long,
- emc->regs + EMC_ZCAL_WAIT_CNT);
-
- udelay(2);
- /* update restored timing */
- err = emc_seq_update_timing(emc);
-
- /* restore early ACK */
- mc_writel(emc->mc, emc->mc_override, MC_EMEM_ARB_OVERRIDE);
-
- if (err)
- return err;
-
- emc->bad_state = false;
+ if (READ_ONCE(emc->bad_state))
+ return -EIO;
return 0;
}
@@ -826,7 +848,13 @@ static int emc_clk_change_notify(struct notifier_block *nb,
switch (msg) {
case PRE_RATE_CHANGE:
+ /*
+ * Disable interrupt since read accesses are prohibited after
+ * stalling.
+ */
+ disable_irq(emc->irq);
err = emc_prepare_timing_change(emc, cnd->new_rate);
+ enable_irq(emc->irq);
break;
case ABORT_RATE_CHANGE:
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