Trusted Firmware-A (TF-A) for rk3399 implements a SiP call to get the on-die termination (ODT) and auto power down parameters from kernel, this patch adds the functionality to do this. Also, if DDR clock frequency is lower than the on-die termination (ODT) disable frequency this driver should disable the DDR ODT.
Signed-off-by: Enric Balletbo i Serra enric.balletbo@collabora.com ---
Changes in v1: - [RFC 3/10] Add an explanation for platform SIP calls. - [RFC 3/10] Change if statement for a switch. - [RFC 3/10] Rename ddr_flag to odt_enable to be more clear.
drivers/devfreq/rk3399_dmc.c | 74 ++++++++++++++++++++++++++++- include/soc/rockchip/rockchip_sip.h | 1 + 2 files changed, 74 insertions(+), 1 deletion(-)
diff --git a/drivers/devfreq/rk3399_dmc.c b/drivers/devfreq/rk3399_dmc.c index e795ad2b3f6b..c619dc4ac620 100644 --- a/drivers/devfreq/rk3399_dmc.c +++ b/drivers/devfreq/rk3399_dmc.c @@ -18,14 +18,17 @@ #include <linux/devfreq.h> #include <linux/devfreq-event.h> #include <linux/interrupt.h> +#include <linux/mfd/syscon.h> #include <linux/module.h> #include <linux/of.h> #include <linux/platform_device.h> #include <linux/pm_opp.h> +#include <linux/regmap.h> #include <linux/regulator/consumer.h> #include <linux/rwsem.h> #include <linux/suspend.h>
+#include <soc/rockchip/rk3399_grf.h> #include <soc/rockchip/rockchip_sip.h>
struct dram_timing { @@ -69,8 +72,11 @@ struct rk3399_dmcfreq { struct mutex lock; struct dram_timing timing; struct regulator *vdd_center; + struct regmap *regmap_pmu; unsigned long rate, target_rate; unsigned long volt, target_volt; + unsigned int odt_dis_freq; + int odt_pd_arg0, odt_pd_arg1; };
static int rk3399_dmcfreq_target(struct device *dev, unsigned long *freq, @@ -80,6 +86,8 @@ static int rk3399_dmcfreq_target(struct device *dev, unsigned long *freq, struct dev_pm_opp *opp; unsigned long old_clk_rate = dmcfreq->rate; unsigned long target_volt, target_rate; + struct arm_smccc_res res; + bool odt_enable = false; int err;
opp = devfreq_recommended_opp(dev, freq, flags); @@ -95,6 +103,19 @@ static int rk3399_dmcfreq_target(struct device *dev, unsigned long *freq,
mutex_lock(&dmcfreq->lock);
+ if (target_rate >= dmcfreq->odt_dis_freq) + odt_enable = true; + + /* + * This makes a SMC call to the TF-A to set the DDR PD (power-down) + * timings and to enable or disable the ODT (on-die termination) + * resistors. + */ + arm_smccc_smc(ROCKCHIP_SIP_DRAM_FREQ, dmcfreq->odt_pd_arg0, + dmcfreq->odt_pd_arg1, + ROCKCHIP_SIP_CONFIG_DRAM_SET_ODT_PD, + odt_enable, 0, 0, 0, &res); + /* * If frequency scaling from low to high, adjust voltage first. * If frequency scaling from high to low, adjust frequency first. @@ -294,11 +315,13 @@ static int rk3399_dmcfreq_probe(struct platform_device *pdev) { struct arm_smccc_res res; struct device *dev = &pdev->dev; - struct device_node *np = pdev->dev.of_node; + struct device_node *np = pdev->dev.of_node, *node; struct rk3399_dmcfreq *data; int ret, index, size; uint32_t *timing; struct dev_pm_opp *opp; + u32 ddr_type; + u32 val;
data = devm_kzalloc(dev, sizeof(struct rk3399_dmcfreq), GFP_KERNEL); if (!data) @@ -334,6 +357,34 @@ static int rk3399_dmcfreq_probe(struct platform_device *pdev) return ret; }
+ /* Try to find the optional reference to the pmu syscon */ + node = of_parse_phandle(np, "rockchip,pmu", 0); + if (node) { + data->regmap_pmu = syscon_node_to_regmap(node); + if (IS_ERR(data->regmap_pmu)) + return PTR_ERR(data->regmap_pmu); + } + + /* Get DDR type */ + regmap_read(data->regmap_pmu, RK3399_PMUGRF_OS_REG2, &val); + ddr_type = (val >> RK3399_PMUGRF_DDRTYPE_SHIFT) & + RK3399_PMUGRF_DDRTYPE_MASK; + + /* Get the odt_dis_freq parameter in function of the DDR type */ + switch (ddr_type) { + case RK3399_PMUGRF_DDRTYPE_DDR3: + data->odt_dis_freq = data->timing.ddr3_odt_dis_freq; + break; + case RK3399_PMUGRF_DDRTYPE_LPDDR3: + data->odt_dis_freq = data->timing.lpddr3_odt_dis_freq; + break; + case RK3399_PMUGRF_DDRTYPE_LPDDR4: + data->odt_dis_freq = data->timing.lpddr4_odt_dis_freq; + break; + default: + return -EINVAL; + }; + /* * Get dram timing and pass it to arm trust firmware, * the dram drvier in arm trust firmware will get these @@ -358,6 +409,27 @@ static int rk3399_dmcfreq_probe(struct platform_device *pdev) ROCKCHIP_SIP_CONFIG_DRAM_INIT, 0, 0, 0, 0, &res);
+ /* + * In TF-A there is a platform SIP call to set the PD (power-down) + * timings and to enable or disable the ODT (on-die termination). + * This call needs three arguments as follows: + * + * arg0: + * bit[0-7] : sr_idle + * bit[8-15] : sr_mc_gate_idle + * bit[16-31] : standby idle + * arg1: + * bit[0-11] : pd_idle + * bit[16-27] : srpd_lite_idle + * arg2: + * bit[0] : odt enable + */ + data->odt_pd_arg0 = (data->timing.sr_idle & 0xff) | + ((data->timing.sr_mc_gate_idle & 0xff) << 8) | + ((data->timing.standby_idle & 0xffff) << 16); + data->odt_pd_arg1 = (data->timing.pd_idle & 0xfff) | + ((data->timing.srpd_lite_idle & 0xfff) << 16); + /* * We add a devfreq driver to our parent since it has a device tree node * with operating points. diff --git a/include/soc/rockchip/rockchip_sip.h b/include/soc/rockchip/rockchip_sip.h index 7e28092c4d3d..ad9482c56797 100644 --- a/include/soc/rockchip/rockchip_sip.h +++ b/include/soc/rockchip/rockchip_sip.h @@ -23,5 +23,6 @@ #define ROCKCHIP_SIP_CONFIG_DRAM_GET_RATE 0x05 #define ROCKCHIP_SIP_CONFIG_DRAM_CLR_IRQ 0x06 #define ROCKCHIP_SIP_CONFIG_DRAM_SET_PARAM 0x07 +#define ROCKCHIP_SIP_CONFIG_DRAM_SET_ODT_PD 0x08
#endif