arm: mx5: add support for core voltage change when switching clock frequency
authorLothar Waßmann <LW@KARO-electronics.de>
Wed, 9 Apr 2014 08:18:28 +0000 (10:18 +0200)
committerLothar Waßmann <LW@KARO-electronics.de>
Wed, 9 Apr 2014 08:18:28 +0000 (10:18 +0200)
arch/arm/cpu/armv7/mx5/clock.c
arch/arm/include/asm/arch-mx5/clock.h
board/karo/tx53/tx53.c

index b4db9ab..a870b08 100644 (file)
@@ -874,11 +874,22 @@ static int config_pll_clk(enum pll_clocks index, struct pll_param *pll_param)
        return 0;
 }
 
+static int __adjust_core_voltage_stub(u32 freq)
+{
+       return 0;
+}
+int adjust_core_voltage(u32 freq)
+       __attribute__((weak, alias("__adjust_core_voltage_stub")));
+
 /* Config CPU clock */
 static int config_core_clk(u32 ref, u32 freq)
 {
        int ret = 0;
        struct pll_param pll_param;
+       u32 cur_freq = decode_pll(mxc_plls[PLL1_CLOCK], MXC_HCLK);
+
+       if (freq == cur_freq)
+               return 0;
 
        memset(&pll_param, 0, sizeof(struct pll_param));
 
@@ -890,8 +901,33 @@ static int config_core_clk(u32 ref, u32 freq)
                        ref / 1000000, ref / 1000 % 1000);
                return ret;
        }
-
-       return config_pll_clk(PLL1_CLOCK, &pll_param);
+       if (freq > cur_freq) {
+               ret = adjust_core_voltage(freq);
+               if (ret < 0) {
+                       printf("Failed to adjust core voltage for changing ARM clk from %u.%03uMHz to  %u.%03uMHz\n",
+                               cur_freq / 1000000, cur_freq / 1000 % 1000,
+                               freq / 1000000, freq / 1000 % 1000);
+                       return ret;
+               }
+               ret = config_pll_clk(PLL1_CLOCK, &pll_param);
+               if (ret) {
+                       adjust_core_voltage(cur_freq);
+               }
+       } else {
+               ret = config_pll_clk(PLL1_CLOCK, &pll_param);
+               if (ret) {
+                       return ret;
+               }
+               ret = adjust_core_voltage(freq);
+               if (ret < 0) {
+                       printf("Failed to adjust core voltage for changing ARM clk from %u.%03uMHz to  %u.%03uMHz\n",
+                               cur_freq / 1000000, cur_freq / 1000 % 1000,
+                               freq / 1000000, freq / 1000 % 1000);
+                       calc_pll_params(ref, cur_freq, &pll_param);
+                       config_pll_clk(PLL1_CLOCK, &pll_param);
+               }
+       }
+       return ret;
 }
 
 static int config_nfc_clk(u32 nfc_clk)
index 1fd3e39..6de0077 100644 (file)
@@ -92,6 +92,7 @@ u32 imx_get_uartclk(void);
 u32 imx_get_fecclk(void);
 unsigned int mxc_get_clock(enum mxc_clock clk);
 int mxc_set_clock(u32 ref, u32 freq, enum mxc_clock clk);
+int adjust_core_voltage(u32 freq);
 void set_usb_phy_clk(void);
 void enable_usb_phy1_clk(unsigned char enable);
 void enable_usb_phy2_clk(unsigned char enable);
index 3c01687..e877b2c 100644 (file)
@@ -189,6 +189,8 @@ static void tx53_print_cpuinfo(void)
 
 enum LTC3589_REGS {
        LTC3589_SCR1 = 0x07,
+       LTC3589_SCR2 = 0x12,
+       LTC3589_VCCR = 0x20,
        LTC3589_CLIRQ = 0x21,
        LTC3589_B1DTV1 = 0x23,
        LTC3589_B1DTV2 = 0x24,
@@ -201,12 +203,15 @@ enum LTC3589_REGS {
        LTC3589_L2DTV2 = 0x33,
 };
 
-#define LTC3589_PGOOD_MASK     (1 << 5)
+#define LTC3589_BnDTV1_PGOOD_MASK      (1 << 5)
+#define LTC3589_BnDTV1_SLEW(n)         (((n) & 3) << 6)
 
-#define LTC3589_CLK_RATE_LOW   (1 << 5)
+#define LTC3589_CLK_RATE_LOW           (1 << 5)
+
+#define LTC3589_SCR2_PGOOD_SHUTDWN     (1 << 7)
 
 #define VDD_LDO2_VAL           mV_to_regval(vout_to_vref(1325 * 10, 2))
-#define VDD_CORE_VAL           mV_to_regval(vout_to_vref(1240 * 10, 3))
+#define VDD_CORE_VAL           mV_to_regval(vout_to_vref(1100 * 10, 3))
 #define VDD_SOC_VAL            mV_to_regval(vout_to_vref(1325 * 10, 4))
 #define VDD_BUCK3_VAL          mV_to_regval(vout_to_vref(2500 * 10, 5))
 
@@ -250,19 +255,23 @@ static struct pmic_regs {
        u8 val;
 } ltc3589_regs[] = {
        { LTC3589_SCR1, 0x15, }, /* burst mode for all regulators except buck boost */
+       { LTC3589_SCR2, LTC3589_SCR2_PGOOD_SHUTDWN, }, /* enable shutdown on PGOOD Timeout */
 
-       { LTC3589_L2DTV1, VDD_LDO2_VAL | LTC3589_PGOOD_MASK, },
+       { LTC3589_L2DTV1, VDD_LDO2_VAL | LTC3589_BnDTV1_SLEW(3) | LTC3589_BnDTV1_PGOOD_MASK, },
        { LTC3589_L2DTV2, VDD_LDO2_VAL | LTC3589_CLK_RATE_LOW, },
 
-       { LTC3589_B1DTV1, VDD_CORE_VAL | LTC3589_PGOOD_MASK, },
+       { LTC3589_B1DTV1, VDD_CORE_VAL | LTC3589_BnDTV1_SLEW(3) | LTC3589_BnDTV1_PGOOD_MASK, },
        { LTC3589_B1DTV2, VDD_CORE_VAL, },
 
-       { LTC3589_B2DTV1, VDD_SOC_VAL | LTC3589_PGOOD_MASK, },
+       { LTC3589_B2DTV1, VDD_SOC_VAL | LTC3589_BnDTV1_SLEW(3) | LTC3589_BnDTV1_PGOOD_MASK, },
        { LTC3589_B2DTV2, VDD_SOC_VAL, },
 
-       { LTC3589_B3DTV1, VDD_BUCK3_VAL | LTC3589_PGOOD_MASK, },
+       { LTC3589_B3DTV1, VDD_BUCK3_VAL | LTC3589_BnDTV1_SLEW(3) | LTC3589_BnDTV1_PGOOD_MASK, },
        { LTC3589_B3DTV2, VDD_BUCK3_VAL, },
 
+       /* Select ref 0 for all regulators and enable slew */
+       { LTC3589_VCCR, 0x55, },
+
        { LTC3589_CLIRQ, 0, }, /* clear all interrupt flags */
 };
 
@@ -305,6 +314,94 @@ static int setup_pmic_voltages(void)
        return 0;
 }
 
+static struct {
+       u32 max_freq;
+       u32 mV;
+} tx53_core_voltages[] = {
+       { 800000000, 1100, },
+       { 1000000000, 1240, },
+       { 1200000000, 1350, },
+};
+
+int adjust_core_voltage(u32 freq)
+{
+       int ret;
+       int i;
+
+       printf("%s@%d\n", __func__, __LINE__);
+
+       for (i = 0; i < ARRAY_SIZE(tx53_core_voltages); i++) {
+               if (freq <= tx53_core_voltages[i].max_freq) {
+                       int retries = 0;
+                       const int max_tries = 10;
+                       const int delay_us = 1;
+                       u32 mV = tx53_core_voltages[i].mV;
+                       u8 val = mV_to_regval(vout_to_vref(mV * 10, 3));
+                       u8 v;
+
+                       printf("regval[%umV]=%02x\n", mV, val);
+
+                       ret = i2c_read(CONFIG_SYS_I2C_SLAVE, LTC3589_B1DTV1, 1,
+                               &v, 1);
+                       if (ret) {
+                               printf("%s: failed to read PMIC register %02x: %d\n",
+                                       __func__, LTC3589_B1DTV1, ret);
+                               return ret;
+                       }
+                       printf("Changing reg %02x from %02x to %02x\n",
+                               LTC3589_B1DTV1, v, (v & ~0x1f) |
+                               mV_to_regval(vout_to_vref(mV * 10, 3)));
+                       v &= ~0x1f;
+                       v |= mV_to_regval(vout_to_vref(mV * 10, 3));
+                       ret = i2c_write(CONFIG_SYS_I2C_SLAVE, LTC3589_B1DTV1, 1,
+                                       &v, 1);
+                       if (ret) {
+                               printf("%s: failed to write PMIC register %02x: %d\n",
+                                       __func__, LTC3589_B1DTV1, ret);
+                               return ret;
+                       }
+                       ret = i2c_read(CONFIG_SYS_I2C_SLAVE, LTC3589_VCCR, 1,
+                                       &v, 1);
+                       if (ret) {
+                               printf("%s: failed to read PMIC register %02x: %d\n",
+                                       __func__, LTC3589_VCCR, ret);
+                               return ret;
+                       }
+                       v |= 0x1;
+                       ret = i2c_write(CONFIG_SYS_I2C_SLAVE, LTC3589_VCCR, 1,
+                                       &v, 1);
+                       if (ret) {
+                               printf("%s: failed to write PMIC register %02x: %d\n",
+                                       __func__, LTC3589_VCCR, ret);
+                               return ret;
+                       }
+                       for (retries = 0; retries < max_tries; retries++) {
+                               ret = i2c_read(CONFIG_SYS_I2C_SLAVE,
+                                       LTC3589_VCCR, 1, &v, 1);
+                               if (ret) {
+                                       printf("%s: failed to read PMIC register %02x: %d\n",
+                                               __func__, LTC3589_VCCR, ret);
+                                       return ret;
+                               }
+                               if (!(v & 1))
+                                       break;
+                               udelay(delay_us);
+                       }
+                       if (v & 1) {
+                               printf("change of VDDCORE did not complete after %uµs\n",
+                                       retries * delay_us);
+                               return -ETIMEDOUT;
+                       }
+
+                       printf("VDDCORE set to %umV after %u loops\n",
+                               DIV_ROUND(vref_to_vout(regval_to_mV(val & 0x1f), 3),
+                                       10), retries);
+                       return 0;
+               }
+       }
+       return -EINVAL;
+}
+
 int board_early_init_f(void)
 {
        struct mxc_ccm_reg *ccm_regs = (void *)CCM_BASE_ADDR;