rockchip: rk3399: add support for ddrfreq suspend/resume

This patch sets the frequency configuration of the next DRAM DFS index
to the configuration of the current index. This does not perform a
frequency transition. It just configures registers so the training on
resume for both indices will be correct.
Signed-off-by: Derek Basehore <dbasehore@chromium.org>
Signed-off-by: Xing Zheng <zhengxing@rock-chips.com>

plat/rockchip/rk3399/drivers/dram/dfs.c

@@ -62,12 +62,20 @@ static const struct pll_div dpll_rates_table[] = {
 struct rk3399_dram_status {
 	uint32_t current_index;
 	uint32_t index_freq[2];
+	uint32_t boot_freq;
 	uint32_t low_power_stat;
 	struct timing_related_config timing_config;
 	struct drv_odt_lp_config drv_odt_lp_cfg;
 };
 
+struct rk3399_saved_status {
+	uint32_t freq;
+	uint32_t low_power_stat;
+	uint32_t odt;
+};
+
 static struct rk3399_dram_status rk3399_dram_status;
+static struct rk3399_saved_status rk3399_suspend_status;
 static uint32_t wrdqs_delay_val[2][2][4];
 
 static struct rk3399_sdram_default_config ddr3_default_config = {
@@ -226,6 +234,7 @@ static void sdram_timing_cfg_init(struct timing_related_config *ptiming_config,
 	ptiming_config->dramds = drv_config->dram_side_drv;
 	ptiming_config->dramodt = drv_config->dram_side_dq_odt;
 	ptiming_config->caodt = drv_config->dram_side_ca_odt;
+	ptiming_config->odt = (mmio_read_32(PHY_REG(0, 5)) >> 16) & 0x1;
 }
 
 struct lat_adj_pair {
@@ -1847,7 +1856,7 @@ static void dram_low_power_config(void)
 
 void dram_dfs_init(void)
 {
-	uint32_t trefi0, trefi1;
+	uint32_t trefi0, trefi1, boot_freq;
 
 	/* get sdram config for os reg */
 	get_dram_drv_odt_val(sdram_config.dramtype,
@@ -1867,8 +1876,15 @@ void dram_dfs_init(void)
 		rk3399_dram_status.index_freq[0] /= 2;
 		rk3399_dram_status.index_freq[1] /= 2;
 	}
-	rk3399_dram_status.index_freq[(rk3399_dram_status.current_index + 1)
-				      & 0x1] = 0;
+	boot_freq =
+		rk3399_dram_status.index_freq[rk3399_dram_status.current_index];
+	boot_freq = dpll_rates_table[to_get_clk_index(boot_freq)].mhz;
+	rk3399_dram_status.boot_freq = boot_freq;
+	rk3399_dram_status.index_freq[rk3399_dram_status.current_index] =
+		boot_freq;
+	rk3399_dram_status.index_freq[(rk3399_dram_status.current_index + 1) &
+				      0x1] = 0;
+	rk3399_dram_status.low_power_stat = 0;
 	/*
 	 * following register decide if NOC stall the access request
 	 * or return error when NOC being idled. when doing ddr frequency
@@ -1883,6 +1899,10 @@ void dram_dfs_init(void)
 	mmio_write_32(GRF_BASE + GRF_SOC_CON(3), 0xffffffff);
 	mmio_write_32(GRF_BASE + GRF_SOC_CON(4), 0x70007000);
 
+	/* Disable multicast */
+	mmio_clrbits_32(PHY_REG(0, 896), 1);
+	mmio_clrbits_32(PHY_REG(1, 896), 1);
+
 	dram_low_power_config();
 }
 
@@ -1974,7 +1994,7 @@ static uint32_t prepare_ddr_timing(uint32_t mhz)
 
 	index = (rk3399_dram_status.current_index + 1) & 0x1;
 	if (rk3399_dram_status.index_freq[index] == mhz)
-		goto out;
+		return index;
 
 	/*
 	 * checking if having available gate traiing timing for
@@ -1990,9 +2010,6 @@ static uint32_t prepare_ddr_timing(uint32_t mhz)
 			      &dram_timing, index);
 	rk3399_dram_status.index_freq[index] = mhz;
 
-out:
-	gen_rk3399_enable_training(rk3399_dram_status.timing_config.ch_cnt,
-				   mhz);
 	return index;
 }
 
@@ -2024,6 +2041,8 @@ uint32_t ddr_set_rate(uint32_t hz)
 	mhz = dpll_rates_table[index].mhz;
 
 	ddr_index = prepare_ddr_timing(mhz);
+	gen_rk3399_enable_training(rk3399_dram_status.timing_config.ch_cnt,
+				   mhz);
 	if (ddr_index > 1)
 		goto out;
 
@@ -2051,3 +2070,57 @@ uint32_t ddr_round_rate(uint32_t hz)
 
 	return dpll_rates_table[index].mhz * 1000 * 1000;
 }
+
+void ddr_prepare_for_sys_suspend(void)
+{
+	uint32_t mhz =
+		rk3399_dram_status.index_freq[rk3399_dram_status.current_index];
+
+	/*
+	 * If we're not currently at the boot (assumed highest) frequency, we
+	 * need to change frequencies to configure out current index.
+	 */
+	rk3399_suspend_status.freq = mhz;
+	exit_low_power();
+	rk3399_suspend_status.low_power_stat =
+		rk3399_dram_status.low_power_stat;
+	rk3399_suspend_status.odt = rk3399_dram_status.timing_config.odt;
+	rk3399_dram_status.low_power_stat = 0;
+	rk3399_dram_status.timing_config.odt = 1;
+	if (mhz != rk3399_dram_status.boot_freq)
+		ddr_set_rate(rk3399_dram_status.boot_freq * 1000 * 1000);
+
+	/*
+	 * This will configure the other index to be the same frequency as the
+	 * current one. We retrain both indices on resume, so both have to be
+	 * setup for the same frequency.
+	 */
+	prepare_ddr_timing(rk3399_dram_status.boot_freq);
+}
+
+void ddr_prepare_for_sys_resume(void)
+{
+	/* Disable multicast */
+	mmio_clrbits_32(PHY_REG(0, 896), 1);
+	mmio_clrbits_32(PHY_REG(1, 896), 1);
+
+	/* The suspend code changes the current index, so reset it now. */
+	rk3399_dram_status.current_index =
+		(mmio_read_32(CTL_REG(0, 111)) >> 16) & 0x3;
+	rk3399_dram_status.low_power_stat =
+		rk3399_suspend_status.low_power_stat;
+	rk3399_dram_status.timing_config.odt = rk3399_suspend_status.odt;
+
+	/*
+	 * Set the saved frequency from suspend if it's different than the
+	 * current frequency.
+	 */
+	if (rk3399_suspend_status.freq !=
+	    rk3399_dram_status.index_freq[rk3399_dram_status.current_index]) {
+		ddr_set_rate(rk3399_suspend_status.freq * 1000 * 1000);
+		return;
+	}
+
+	gen_rk3399_set_odt(rk3399_dram_status.timing_config.odt);
+	resume_low_power(rk3399_dram_status.low_power_stat);
+}

plat/rockchip/rk3399/drivers/dram/dfs.h

@@ -66,4 +66,7 @@ uint32_t ddr_round_rate(uint32_t hz);
 uint32_t ddr_get_rate(void);
 uint32_t dram_set_odt_pd(uint32_t arg0, uint32_t arg1, uint32_t arg2);
 void dram_dfs_init(void);
+void ddr_prepare_for_sys_suspend(void);
+void ddr_prepare_for_sys_resume(void);
+
 #endif

plat/rockchip/rk3399/drivers/dram/suspend.c

@@ -571,14 +571,15 @@ static __sramfunc void pctl_cfg(uint32_t ch,
 	sram_regcpy(PHY_REG(ch, 768), (uintptr_t)&params_phy[768], 38);
 }
 
-static __sramfunc int dram_switch_to_phy_index1(
+static __sramfunc int dram_switch_to_next_index(
 		struct rk3399_sdram_params *sdram_params)
 {
 	uint32_t ch, ch_count;
+	uint32_t fn = ((mmio_read_32(CTL_REG(0, 111)) >> 16) + 1) & 0x1;
 
 	mmio_write_32(CIC_BASE + CIC_CTRL0,
 		      (((0x3 << 4) | (1 << 2) | 1) << 16) |
-		      (1 << 4) | (1 << 2) | 1);
+		      (fn << 4) | (1 << 2) | 1);
 	while (!(mmio_read_32(CIC_BASE + CIC_STATUS0) & (1 << 2)))
 		;
 
@@ -591,7 +592,7 @@ static __sramfunc int dram_switch_to_phy_index1(
 	/* LPDDR4 f2 cann't do training, all training will fail */
 	for (ch = 0; ch < ch_count; ch++) {
 		mmio_clrsetbits_32(PHY_REG(ch, 896), (0x3 << 8) | 1,
-				   1 << 8);
+				   fn << 8);
 
 		/* data_training failed */
 		if (data_training(ch, sdram_params, PI_FULL_TRAINING))
@@ -754,5 +755,5 @@ retry:
 	dram_all_config(sdram_params);
 
 	/* Switch to index 1 and prepare for DDR frequency switch. */
-	dram_switch_to_phy_index1(sdram_params);
+	dram_switch_to_next_index(sdram_params);
 }

plat/rockchip/rk3399/drivers/pmu/pmu.c

@@ -33,6 +33,7 @@
 #include <bakery_lock.h>
 #include <debug.h>
 #include <delay_timer.h>
+#include <dfs.h>
 #include <errno.h>
 #include <gpio.h>
 #include <mmio.h>
@@ -1076,6 +1077,7 @@ static int sys_pwr_domain_suspend(void)
 	uint32_t wait_cnt = 0;
 	uint32_t status = 0;
 
+	ddr_prepare_for_sys_suspend();
 	dmc_save();
 	pmu_scu_b_pwrdn();
 
@@ -1219,6 +1221,8 @@ static int sys_pwr_domain_resume(void)
 
 	m0_stop();
 
+	ddr_prepare_for_sys_resume();
+
 	return 0;
 }