regulators: anatop: add set_voltage_time_sel interface

some of anatop's regulators(cpu, vddpu and vddsoc) have
register settings about LDO's step time, which will impact
the LDO ramp up speed, need to use set_voltage_time_sel
interface to add necessary delay everytime LDOs' voltage
is increased.

offset 0x170:
bit [24-25]: cpu
bit [26-27]: vddpu
bit [28-29]: vddsoc

field definition:
0'b00: 64 cycles of 24M clock;
0'b01: 128 cycles of 24M clock;
0'b02: 256 cycles of 24M clock;
0'b03: 512 cycles of 24M clock;

Signed-off-by: Anson Huang <b20788@freescale.com>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

diff --git a/Documentation/devicetree/bindings/regulator/anatop-regulator.txt b/Documentation/devicetree/bindings/regulator/anatop-regulator.txt
index 357758cb6e92f6078da84aa8bd516f8a87af21bc..758eae24082a56567fbad2c9069a66606f7c4708 100644 (file)
--- a/Documentation/devicetree/bindings/regulator/anatop-regulator.txt
+++ b/Documentation/devicetree/bindings/regulator/anatop-regulator.txt
@@ -9,6 +9,11 @@ Required properties:
 - anatop-min-voltage: Minimum voltage of this regulator
 - anatop-max-voltage: Maximum voltage of this regulator
 
+Optional properties:
+- anatop-delay-reg-offset: Anatop MFD step time register offset
+- anatop-delay-bit-shift: Bit shift for the step time register
+- anatop-delay-bit-width: Number of bits used in the step time register
+
 Any property defined as part of the core regulator
 binding, defined in regulator.txt, can also be used.
 
@@ -23,6 +28,9 @@ Example:
                anatop-reg-offset = <0x140>;
                anatop-vol-bit-shift = <9>;
                anatop-vol-bit-width = <5>;
+               anatop-delay-reg-offset = <0x170>;
+               anatop-delay-bit-shift = <24>;
+               anatop-delay-bit-width = <2>;
                anatop-min-bit-val = <1>;
                anatop-min-voltage = <725000>;
                anatop-max-voltage = <1300000>;

diff --git a/drivers/regulator/anatop-regulator.c b/drivers/regulator/anatop-regulator.c
index 8f39cac661d26deb4025e2787add57f22dc50db2..0df9c6a97604d50885ba3f43e26d51de9af67c77 100644 (file)
--- a/drivers/regulator/anatop-regulator.c
+++ b/drivers/regulator/anatop-regulator.c
@@ -31,12 +31,18 @@
 #include <linux/regulator/driver.h>
 #include <linux/regulator/of_regulator.h>
 
+#define LDO_RAMP_UP_UNIT_IN_CYCLES      64 /* 64 cycles per step */
+#define LDO_RAMP_UP_FREQ_IN_MHZ         24 /* cycle based on 24M OSC */
+
 struct anatop_regulator {
        const char *name;
        u32 control_reg;
        struct regmap *anatop;
        int vol_bit_shift;
        int vol_bit_width;
+       u32 delay_reg;
+       int delay_bit_shift;
+       int delay_bit_width;
        int min_bit_val;
        int min_voltage;
        int max_voltage;
@@ -55,6 +61,32 @@ static int anatop_regmap_set_voltage_sel(struct regulator_dev *reg,
        return regulator_set_voltage_sel_regmap(reg, selector);
 }
 
+static int anatop_regmap_set_voltage_time_sel(struct regulator_dev *reg,
+       unsigned int old_sel,
+       unsigned int new_sel)
+{
+       struct anatop_regulator *anatop_reg = rdev_get_drvdata(reg);
+       u32 val;
+       int ret = 0;
+
+       /* check whether need to care about LDO ramp up speed */
+       if (anatop_reg->delay_bit_width && new_sel > old_sel) {
+               /*
+                * the delay for LDO ramp up time is
+                * based on the register setting, we need
+                * to calculate how many steps LDO need to
+                * ramp up, and how much delay needed. (us)
+                */
+               regmap_read(anatop_reg->anatop, anatop_reg->delay_reg, &val);
+               val = (val >> anatop_reg->delay_bit_shift) &
+                       ((1 << anatop_reg->delay_bit_width) - 1);
+               ret = (new_sel - old_sel) * ((LDO_RAMP_UP_UNIT_IN_CYCLES <<
+                       val) / LDO_RAMP_UP_FREQ_IN_MHZ + 1);
+       }
+
+       return ret;
+}
+
 static int anatop_regmap_get_voltage_sel(struct regulator_dev *reg)
 {
        struct anatop_regulator *anatop_reg = rdev_get_drvdata(reg);
@@ -67,6 +99,7 @@ static int anatop_regmap_get_voltage_sel(struct regulator_dev *reg)
 
 static struct regulator_ops anatop_rops = {
        .set_voltage_sel = anatop_regmap_set_voltage_sel,
+       .set_voltage_time_sel = anatop_regmap_set_voltage_time_sel,
        .get_voltage_sel = anatop_regmap_get_voltage_sel,
        .list_voltage = regulator_list_voltage_linear,
        .map_voltage = regulator_map_voltage_linear,
@@ -143,6 +176,14 @@ static int anatop_regulator_probe(struct platform_device *pdev)
                goto anatop_probe_end;
        }
 
+       /* read LDO ramp up setting, only for core reg */
+       of_property_read_u32(np, "anatop-delay-reg-offset",
+                            &sreg->delay_reg);
+       of_property_read_u32(np, "anatop-delay-bit-width",
+                            &sreg->delay_bit_width);
+       of_property_read_u32(np, "anatop-delay-bit-shift",
+                            &sreg->delay_bit_shift);
+
        rdesc->n_voltages = (sreg->max_voltage - sreg->min_voltage) / 25000 + 1
                            + sreg->min_bit_val;
        rdesc->min_uV = sreg->min_voltage;