The DFLL hardware supports two modes (I2C and PWM) for voltage control
when requesting a frequency. In this patch, we introduce PWM mode support.
To support that, we re-organize the LUT for unifying the table for both
cases of I2C and PWM mode. And generate that based on regulator info.
For the PWM-based regulator, we get this info from DT. And do the same as
the case of I2C LUT, which can help to map the PMIC voltage ID and voltages
that the regulator supported.
The other parts are the support code for initializing the DFLL hardware
to support PWM mode. Also, the register debugfs file is slightly
reworked to only show the i2c registers when I2C mode is in use.
Based on the work of Peter De Schrijver <pdeschrijver@xxxxxxxxxx>.
Signed-off-by: Joseph Lo <josephl@xxxxxxxxxx>
---
drivers/clk/tegra/clk-dfll.c | 431 ++++++++++++++++++++++++++++++-----
1 file changed, 368 insertions(+), 63 deletions(-)
diff --git a/drivers/clk/tegra/clk-dfll.c b/drivers/clk/tegra/clk-dfll.c
index 609e363dabf8..c294a2989f31 100644
--- a/drivers/clk/tegra/clk-dfll.c
+++ b/drivers/clk/tegra/clk-dfll.c
@@ -1,7 +1,7 @@
/*
* clk-dfll.c - Tegra DFLL clock source common code
*
- * Copyright (C) 2012-2014 NVIDIA Corporation. All rights reserved.
+ * Copyright (C) 2012-2018 NVIDIA Corporation. All rights reserved.
*
* Aleksandr Frid <afrid@xxxxxxxxxx>
* Paul Walmsley <pwalmsley@xxxxxxxxxx>
@@ -47,6 +47,7 @@
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
+#include <linux/pinctrl/consumer.h>
#include <linux/pm_opp.h>
#include <linux/pm_runtime.h>
#include <linux/regmap.h>
@@ -243,6 +244,12 @@ enum dfll_tune_range {
DFLL_TUNE_LOW = 1,
};
+
+enum tegra_dfll_pmu_if {
+ TEGRA_DFLL_PMU_I2C = 0,
+ TEGRA_DFLL_PMU_PWM = 1,
+};
+
/**
* struct dfll_rate_req - target DFLL rate request data
* @rate: target frequency, after the postscaling
@@ -294,16 +301,25 @@ struct tegra_dfll {
u32 ci;
u32 cg;
bool cg_scale;
+ u32 reg_init_uV;
/* I2C interface parameters */
u32 i2c_fs_rate;
u32 i2c_reg;
u32 i2c_slave_addr;
- /* i2c_lut array entries are regulator framework selectors */
- unsigned i2c_lut[MAX_DFLL_VOLTAGES];
- int i2c_lut_size;
- u8 lut_min, lut_max, lut_safe;
+ /* lut array entries are regulator framework selectors or PWM values*/
+ unsigned lut[MAX_DFLL_VOLTAGES];
+ unsigned lut_uv[MAX_DFLL_VOLTAGES];
+ int lut_size;
+ u8 lut_bottom, lut_min, lut_max, lut_safe;
+
+ /* PWM interface */
+ enum tegra_dfll_pmu_if pmu_if;
+ unsigned long pwm_rate;
+ struct pinctrl *pwm_pin;
+ struct pinctrl_state *pwm_enable_state;
+ struct pinctrl_state *pwm_disable_state;
};
#define clk_hw_to_dfll(_hw) container_of(_hw, struct tegra_dfll, dfll_clk_hw)
@@ -489,6 +505,34 @@ static void dfll_set_mode(struct tegra_dfll *td,
dfll_wmb(td);
}
+/*
+ * DVCO rate control
+ */
+
+static unsigned long get_dvco_rate_below(struct tegra_dfll *td, u8 out_min)
+{
+ struct dev_pm_opp *opp;
+ unsigned long rate, prev_rate;
+ int uv, min_uv;
+
+ min_uv = td->lut_uv[out_min];
+ for (rate = 0, prev_rate = 0; ; rate++) {
+ opp = dev_pm_opp_find_freq_ceil(td->soc->dev, &rate);
+ if (IS_ERR(opp))
+ break;
+
+ uv = dev_pm_opp_get_voltage(opp);
