ARM: OMAP3: VC: calculate ramp times

[firefly-linux-kernel-4.4.55.git] / arch / arm / mach-omap2 / vc.c

diff --git a/arch/arm/mach-omap2/vc.c b/arch/arm/mach-omap2/vc.c
index 4c3c41fd26373cfd1cd0eb519fd358a170aed0d7..73b4bcd67023059b148cdca7704728fd0edaa92c 100644 (file)
--- a/arch/arm/mach-omap2/vc.c
+++ b/arch/arm/mach-omap2/vc.c
@@ -204,29 +204,109 @@ int omap_vc_bypass_scale(struct voltagedomain *voltdm,
        return 0;
 }
 
-static void __init omap3_vfsm_init(struct voltagedomain *voltdm)
+/**
+ * omap3_set_i2c_timings - sets i2c sleep timings for a channel
+ * @voltdm: channel to configure
+ * @off_mode: select whether retention or off mode values used
+ *
+ * Calculates and sets up voltage controller to use I2C based
+ * voltage scaling for sleep modes. This can be used for either off mode
+ * or retention. Off mode has additionally an option to use sys_off_mode
+ * pad, which uses a global signal to program the whole power IC to
+ * off-mode.
+ */
+static void omap3_set_i2c_timings(struct voltagedomain *voltdm, bool off_mode)
 {
+       unsigned long voltsetup1;
+       u32 tgt_volt;
+
+       if (off_mode)
+               tgt_volt = voltdm->vc_param->off;
+       else
+               tgt_volt = voltdm->vc_param->ret;
+
+       voltsetup1 = (voltdm->vc_param->on - tgt_volt) /
+                       voltdm->pmic->slew_rate;
+
+       voltsetup1 = voltsetup1 * voltdm->sys_clk.rate / 8 / 1000000 + 1;
+
+       voltdm->rmw(voltdm->vfsm->voltsetup_mask,
+               voltsetup1 << __ffs(voltdm->vfsm->voltsetup_mask),
+               voltdm->vfsm->voltsetup_reg);
+
        /*
-        * Voltage Manager FSM parameters init
-        * XXX This data should be passed in from the board file
+        * pmic is not controlling the voltage scaling during retention,
+        * thus set voltsetup2 to 0
         */
-       voltdm->write(OMAP3_CLKSETUP, OMAP3_PRM_CLKSETUP_OFFSET);
-       voltdm->write(OMAP3_VOLTOFFSET, OMAP3_PRM_VOLTOFFSET_OFFSET);
-       voltdm->write(OMAP3_VOLTSETUP2, OMAP3_PRM_VOLTSETUP2_OFFSET);
+       voltdm->write(0, OMAP3_PRM_VOLTSETUP2_OFFSET);
 }
 
-static void __init omap3_vc_init_channel(struct voltagedomain *voltdm)
+/**
+ * omap3_set_off_timings - sets off-mode timings for a channel
+ * @voltdm: channel to configure
+ *
+ * Calculates and sets up off-mode timings for a channel. Off-mode
+ * can use either I2C based voltage scaling, or alternatively
+ * sys_off_mode pad can be used to send a global command to power IC.
+ * This function first checks which mode is being used, and calls
+ * omap3_set_i2c_timings() if the system is using I2C control mode.
+ * sys_off_mode has the additional benefit that voltages can be
+ * scaled to zero volt level with TWL4030 / TWL5030, I2C can only
+ * scale to 600mV.
+ */
+static void omap3_set_off_timings(struct voltagedomain *voltdm)
 {
-       static bool is_initialized;
+       unsigned long clksetup;
+       unsigned long voltsetup2;
+       unsigned long voltsetup2_old;
+       u32 val;
 
-       if (is_initialized)
+       /* check if sys_off_mode is used to control off-mode voltages */
+       val = voltdm->read(OMAP3_PRM_VOLTCTRL_OFFSET);
+       if (!(val & OMAP3430_SEL_OFF_MASK)) {
+               /* No, omap is controlling them over I2C */
+               omap3_set_i2c_timings(voltdm, true);
                return;
+       }
 
-       omap3_vfsm_init(voltdm);
+       clksetup = voltdm->read(OMAP3_PRM_CLKSETUP_OFFSET);
 
-       is_initialized = true;
+       /* voltsetup 2 in us */
+       voltsetup2 = voltdm->vc_param->on / voltdm->pmic->slew_rate;
+
+       /* convert to 32k clk cycles */
+       voltsetup2 = DIV_ROUND_UP(voltsetup2 * 32768, 1000000);
+
+       voltsetup2_old = voltdm->read(OMAP3_PRM_VOLTSETUP2_OFFSET);
+
+       /*
+        * Update voltsetup2 if higher than current value (needed because
+        * we have multiple channels with different ramp times), also
+        * update voltoffset always to value recommended by TRM
+        */
+       if (voltsetup2 > voltsetup2_old) {
+               voltdm->write(voltsetup2, OMAP3_PRM_VOLTSETUP2_OFFSET);
+               voltdm->write(clksetup - voltsetup2,
+                       OMAP3_PRM_VOLTOFFSET_OFFSET);
+       } else
+               voltdm->write(clksetup - voltsetup2_old,
+                       OMAP3_PRM_VOLTOFFSET_OFFSET);
+
+       /*
+        * omap is not controlling voltage scaling during off-mode,
+        * thus set voltsetup1 to 0
+        */
+       voltdm->rmw(voltdm->vfsm->voltsetup_mask, 0,
+               voltdm->vfsm->voltsetup_reg);
+
+       /* voltoffset must be clksetup minus voltsetup2 according to TRM */
+       voltdm->write(clksetup - voltsetup2, OMAP3_PRM_VOLTOFFSET_OFFSET);
 }
 
+static void __init omap3_vc_init_channel(struct voltagedomain *voltdm)
+{
+       omap3_set_off_timings(voltdm);
+}
 
 /* OMAP4 specific voltage init functions */
 static void __init omap4_vc_init_channel(struct voltagedomain *voltdm)
@@ -337,7 +417,6 @@ void __init omap_vc_init_channel(struct voltagedomain *voltdm)
        vc->i2c_slave_addr = voltdm->pmic->i2c_slave_addr;
        vc->volt_reg_addr = voltdm->pmic->volt_reg_addr;
        vc->cmd_reg_addr = voltdm->pmic->cmd_reg_addr;
-       vc->setup_time = voltdm->pmic->volt_setup_time;
 
        /* Configure the i2c slave address for this VC */
        voltdm->rmw(vc->smps_sa_mask,
@@ -376,11 +455,6 @@ void __init omap_vc_init_channel(struct voltagedomain *voltdm)
        /* Channel configuration */
        omap_vc_config_channel(voltdm);
 
-       /* Configure the setup times */
-       voltdm->rmw(voltdm->vfsm->voltsetup_mask,
-                   vc->setup_time << __ffs(voltdm->vfsm->voltsetup_mask),
-                   voltdm->vfsm->voltsetup_reg);
-
        omap_vc_i2c_init(voltdm);
 
        if (cpu_is_omap34xx())