[PATCH u-boot] adc: add Amlogic Meson SAR ADC driver
Neil Armstrong
narmstrong at baylibre.com
Mon Apr 23 07:19:23 PDT 2018
This patch adds the driver for the Amlogic Meson Successive Approximation
Register (SAR) A/D Converter based on the Linux IIO driver thanks to the
great work of Martin Blumenstingl.
The driver has been adapted to U-Boot and the ADC UClass.
This patch depends on the regmap "regmap: add regmap_update_bits() helper"
patch and has been tested using the newly introducted "adc" CLI command
in the "cmd: add ADC cli commands" patch.
Signed-off-by: Neil Armstrong <narmstrong at baylibre.com>
---
drivers/adc/Kconfig | 10 +
drivers/adc/Makefile | 1 +
drivers/adc/meson-saradc.c | 724 +++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 735 insertions(+)
create mode 100644 drivers/adc/meson-saradc.c
diff --git a/drivers/adc/Kconfig b/drivers/adc/Kconfig
index 8094420..93e27f1 100644
--- a/drivers/adc/Kconfig
+++ b/drivers/adc/Kconfig
@@ -29,6 +29,16 @@ config ADC_SANDBOX
- 16-bit resolution
- single and multi-channel conversion mode
+config SARADC_MESON
+ bool "Enable Amlogic Meson SARADC driver"
+ imply REGMAP
+ help
+ This enables driver for Amlogic Meson SARADC.
+ It provides:
+ - 8 analog input channels
+ - 1O or 12 bits resolution
+ - Up to 1MSPS of sample rate
+
config SARADC_ROCKCHIP
bool "Enable Rockchip SARADC driver"
help
diff --git a/drivers/adc/Makefile b/drivers/adc/Makefile
index 4b5aa69..95c93d4 100644
--- a/drivers/adc/Makefile
+++ b/drivers/adc/Makefile
@@ -9,3 +9,4 @@ obj-$(CONFIG_ADC) += adc-uclass.o
obj-$(CONFIG_ADC_EXYNOS) += exynos-adc.o
obj-$(CONFIG_ADC_SANDBOX) += sandbox.o
obj-$(CONFIG_SARADC_ROCKCHIP) += rockchip-saradc.o
+obj-$(CONFIG_SARADC_MESON) += meson-saradc.o
diff --git a/drivers/adc/meson-saradc.c b/drivers/adc/meson-saradc.c
new file mode 100644
index 0000000..0df6f43
--- /dev/null
+++ b/drivers/adc/meson-saradc.c
@@ -0,0 +1,724 @@
+/*
+ * Copyright (C) 2017 Martin Blumenstingl <martin.blumenstingl at googlemail.com>
+ * Copyright (C) 2018 BayLibre, SAS
+ * Author: Neil Armstrong <narmstrong at baylibre.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ *
+ * Amlogic Meson Successive Approximation Register (SAR) A/D Converter
+ */
+
+#include <common.h>
+#include <adc.h>
+#include <clk.h>
+#include <dm.h>
+#include <regmap.h>
+#include <errno.h>
+#include <asm/io.h>
+#include <linux/math64.h>
+#include <linux/bitfield.h>
+
+#define MESON_SAR_ADC_REG0 0x00
+ #define MESON_SAR_ADC_REG0_PANEL_DETECT BIT(31)
+ #define MESON_SAR_ADC_REG0_BUSY_MASK GENMASK(30, 28)
+ #define MESON_SAR_ADC_REG0_DELTA_BUSY BIT(30)
+ #define MESON_SAR_ADC_REG0_AVG_BUSY BIT(29)
+ #define MESON_SAR_ADC_REG0_SAMPLE_BUSY BIT(28)
+ #define MESON_SAR_ADC_REG0_FIFO_FULL BIT(27)
+ #define MESON_SAR_ADC_REG0_FIFO_EMPTY BIT(26)
+ #define MESON_SAR_ADC_REG0_FIFO_COUNT_MASK GENMASK(25, 21)
+ #define MESON_SAR_ADC_REG0_ADC_BIAS_CTRL_MASK GENMASK(20, 19)
+ #define MESON_SAR_ADC_REG0_CURR_CHAN_ID_MASK GENMASK(18, 16)
+ #define MESON_SAR_ADC_REG0_ADC_TEMP_SEN_SEL BIT(15)
+ #define MESON_SAR_ADC_REG0_SAMPLING_STOP BIT(14)
+ #define MESON_SAR_ADC_REG0_CHAN_DELTA_EN_MASK GENMASK(13, 12)
+ #define MESON_SAR_ADC_REG0_DETECT_IRQ_POL BIT(10)
+ #define MESON_SAR_ADC_REG0_DETECT_IRQ_EN BIT(9)
+ #define MESON_SAR_ADC_REG0_FIFO_CNT_IRQ_MASK GENMASK(8, 4)
+ #define MESON_SAR_ADC_REG0_FIFO_IRQ_EN BIT(3)
+ #define MESON_SAR_ADC_REG0_SAMPLING_START BIT(2)
+ #define MESON_SAR_ADC_REG0_CONTINUOUS_EN BIT(1)
+ #define MESON_SAR_ADC_REG0_SAMPLE_ENGINE_ENABLE BIT(0)
+
+#define MESON_SAR_ADC_CHAN_LIST 0x04
+ #define MESON_SAR_ADC_CHAN_LIST_MAX_INDEX_MASK GENMASK(26, 24)
+ #define MESON_SAR_ADC_CHAN_LIST_ENTRY_MASK(_chan) \
+ (GENMASK(2, 0) << ((_chan) * 3))
+
+#define MESON_SAR_ADC_AVG_CNTL 0x08
+ #define MESON_SAR_ADC_AVG_CNTL_AVG_MODE_SHIFT(_chan) \
+ (16 + ((_chan) * 2))
+ #define MESON_SAR_ADC_AVG_CNTL_AVG_MODE_MASK(_chan) \
+ (GENMASK(17, 16) << ((_chan) * 2))
+ #define MESON_SAR_ADC_AVG_CNTL_NUM_SAMPLES_SHIFT(_chan) \
+ (0 + ((_chan) * 2))
+ #define MESON_SAR_ADC_AVG_CNTL_NUM_SAMPLES_MASK(_chan) \
+ (GENMASK(1, 0) << ((_chan) * 2))
+
+#define MESON_SAR_ADC_REG3 0x0c
+ #define MESON_SAR_ADC_REG3_CNTL_USE_SC_DLY BIT(31)
+ #define MESON_SAR_ADC_REG3_CLK_EN BIT(30)
+ #define MESON_SAR_ADC_REG3_BL30_INITIALIZED BIT(28)
+ #define MESON_SAR_ADC_REG3_CTRL_CONT_RING_COUNTER_EN BIT(27)
+ #define MESON_SAR_ADC_REG3_CTRL_SAMPLING_CLOCK_PHASE BIT(26)
+ #define MESON_SAR_ADC_REG3_CTRL_CHAN7_MUX_SEL_MASK GENMASK(25, 23)
+ #define MESON_SAR_ADC_REG3_DETECT_EN BIT(22)
+ #define MESON_SAR_ADC_REG3_ADC_EN BIT(21)
+ #define MESON_SAR_ADC_REG3_PANEL_DETECT_COUNT_MASK GENMASK(20, 18)
+ #define MESON_SAR_ADC_REG3_PANEL_DETECT_FILTER_TB_MASK GENMASK(17, 16)
+ #define MESON_SAR_ADC_REG3_ADC_CLK_DIV_SHIFT 10
+ #define MESON_SAR_ADC_REG3_ADC_CLK_DIV_WIDTH 5
+ #define MESON_SAR_ADC_REG3_BLOCK_DLY_SEL_MASK GENMASK(9, 8)
+ #define MESON_SAR_ADC_REG3_BLOCK_DLY_MASK GENMASK(7, 0)
+
+#define MESON_SAR_ADC_DELAY 0x10
+ #define MESON_SAR_ADC_DELAY_INPUT_DLY_SEL_MASK GENMASK(25, 24)
+ #define MESON_SAR_ADC_DELAY_BL30_BUSY BIT(15)
+ #define MESON_SAR_ADC_DELAY_KERNEL_BUSY BIT(14)
+ #define MESON_SAR_ADC_DELAY_INPUT_DLY_CNT_MASK GENMASK(23, 16)
+ #define MESON_SAR_ADC_DELAY_SAMPLE_DLY_SEL_MASK GENMASK(9, 8)
+ #define MESON_SAR_ADC_DELAY_SAMPLE_DLY_CNT_MASK GENMASK(7, 0)
+
+#define MESON_SAR_ADC_LAST_RD 0x14
+ #define MESON_SAR_ADC_LAST_RD_LAST_CHANNEL1_MASK GENMASK(23, 16)
+ #define MESON_SAR_ADC_LAST_RD_LAST_CHANNEL0_MASK GENMASK(9, 0)
+
+#define MESON_SAR_ADC_FIFO_RD 0x18
+ #define MESON_SAR_ADC_FIFO_RD_CHAN_ID_MASK GENMASK(14, 12)
+ #define MESON_SAR_ADC_FIFO_RD_SAMPLE_VALUE_MASK GENMASK(11, 0)
+
+#define MESON_SAR_ADC_AUX_SW 0x1c
+ #define MESON_SAR_ADC_AUX_SW_MUX_SEL_CHAN_SHIFT(_chan) \
+ (8 + (((_chan) - 2) * 3))
+ #define MESON_SAR_ADC_AUX_SW_VREF_P_MUX BIT(6)
+ #define MESON_SAR_ADC_AUX_SW_VREF_N_MUX BIT(5)
+ #define MESON_SAR_ADC_AUX_SW_MODE_SEL BIT(4)
+ #define MESON_SAR_ADC_AUX_SW_YP_DRIVE_SW BIT(3)
+ #define MESON_SAR_ADC_AUX_SW_XP_DRIVE_SW BIT(2)
+ #define MESON_SAR_ADC_AUX_SW_YM_DRIVE_SW BIT(1)
+ #define MESON_SAR_ADC_AUX_SW_XM_DRIVE_SW BIT(0)
+
+#define MESON_SAR_ADC_CHAN_10_SW 0x20
+ #define MESON_SAR_ADC_CHAN_10_SW_CHAN1_MUX_SEL_MASK GENMASK(25, 23)
+ #define MESON_SAR_ADC_CHAN_10_SW_CHAN1_VREF_P_MUX BIT(22)
+ #define MESON_SAR_ADC_CHAN_10_SW_CHAN1_VREF_N_MUX BIT(21)
+ #define MESON_SAR_ADC_CHAN_10_SW_CHAN1_MODE_SEL BIT(20)
+ #define MESON_SAR_ADC_CHAN_10_SW_CHAN1_YP_DRIVE_SW BIT(19)
+ #define MESON_SAR_ADC_CHAN_10_SW_CHAN1_XP_DRIVE_SW BIT(18)
+ #define MESON_SAR_ADC_CHAN_10_SW_CHAN1_YM_DRIVE_SW BIT(17)
+ #define MESON_SAR_ADC_CHAN_10_SW_CHAN1_XM_DRIVE_SW BIT(16)
+ #define MESON_SAR_ADC_CHAN_10_SW_CHAN0_MUX_SEL_MASK GENMASK(9, 7)
+ #define MESON_SAR_ADC_CHAN_10_SW_CHAN0_VREF_P_MUX BIT(6)
+ #define MESON_SAR_ADC_CHAN_10_SW_CHAN0_VREF_N_MUX BIT(5)
+ #define MESON_SAR_ADC_CHAN_10_SW_CHAN0_MODE_SEL BIT(4)
+ #define MESON_SAR_ADC_CHAN_10_SW_CHAN0_YP_DRIVE_SW BIT(3)
+ #define MESON_SAR_ADC_CHAN_10_SW_CHAN0_XP_DRIVE_SW BIT(2)
+ #define MESON_SAR_ADC_CHAN_10_SW_CHAN0_YM_DRIVE_SW BIT(1)
+ #define MESON_SAR_ADC_CHAN_10_SW_CHAN0_XM_DRIVE_SW BIT(0)
+
+#define MESON_SAR_ADC_DETECT_IDLE_SW 0x24
+ #define MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_SW_EN BIT(26)
+ #define MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_MUX_MASK GENMASK(25, 23)
+ #define MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_VREF_P_MUX BIT(22)
+ #define MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_VREF_N_MUX BIT(21)
+ #define MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_MODE_SEL BIT(20)
+ #define MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_YP_DRIVE_SW BIT(19)
+ #define MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_XP_DRIVE_SW BIT(18)
+ #define MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_YM_DRIVE_SW BIT(17)
+ #define MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_XM_DRIVE_SW BIT(16)
+ #define MESON_SAR_ADC_DETECT_IDLE_SW_IDLE_MUX_SEL_MASK GENMASK(9, 7)
+ #define MESON_SAR_ADC_DETECT_IDLE_SW_IDLE_VREF_P_MUX BIT(6)
+ #define MESON_SAR_ADC_DETECT_IDLE_SW_IDLE_VREF_N_MUX BIT(5)
+ #define MESON_SAR_ADC_DETECT_IDLE_SW_IDLE_MODE_SEL BIT(4)
+ #define MESON_SAR_ADC_DETECT_IDLE_SW_IDLE_YP_DRIVE_SW BIT(3)
+ #define MESON_SAR_ADC_DETECT_IDLE_SW_IDLE_XP_DRIVE_SW BIT(2)
+ #define MESON_SAR_ADC_DETECT_IDLE_SW_IDLE_YM_DRIVE_SW BIT(1)
+ #define MESON_SAR_ADC_DETECT_IDLE_SW_IDLE_XM_DRIVE_SW BIT(0)
+
+#define MESON_SAR_ADC_DELTA_10 0x28
+ #define MESON_SAR_ADC_DELTA_10_TEMP_SEL BIT(27)
+ #define MESON_SAR_ADC_DELTA_10_TS_REVE1 BIT(26)
+ #define MESON_SAR_ADC_DELTA_10_CHAN1_DELTA_VALUE_MASK GENMASK(25, 16)
+ #define MESON_SAR_ADC_DELTA_10_TS_REVE0 BIT(15)
+ #define MESON_SAR_ADC_DELTA_10_TS_C_SHIFT 11
+ #define MESON_SAR_ADC_DELTA_10_TS_C_MASK GENMASK(14, 11)
+ #define MESON_SAR_ADC_DELTA_10_TS_VBG_EN BIT(10)
+ #define MESON_SAR_ADC_DELTA_10_CHAN0_DELTA_VALUE_MASK GENMASK(9, 0)
+
+/*
+ * NOTE: registers from here are undocumented (the vendor Linux kernel driver
+ * and u-boot source served as reference). These only seem to be relevant on
+ * GXBB and newer.
+ */
+#define MESON_SAR_ADC_REG11 0x2c
+ #define MESON_SAR_ADC_REG11_BANDGAP_EN BIT(13)
+
+#define MESON_SAR_ADC_REG13 0x34
+ #define MESON_SAR_ADC_REG13_12BIT_CALIBRATION_MASK GENMASK(13, 8)
+
+#define MESON_SAR_ADC_MAX_FIFO_SIZE 32
+#define MESON_SAR_ADC_TIMEOUT 100 /* ms */
+
+#define NUM_CHANNELS 8
+
+#define MILLION 1000000
+
+struct meson_saradc_data {
+ int num_bits;
+};
+
+struct meson_saradc_priv {
+ const struct meson_saradc_data *data;
+ struct regmap *regmap;
+ struct clk core_clk;
+ struct clk adc_clk;
+ bool initialized;
+ int active_channel;
+ int calibbias;
+ int calibscale;
+};
+
+static unsigned int
+meson_saradc_get_fifo_count(struct meson_saradc_priv *priv)
+{
+ u32 regval;
+
+ regmap_read(priv->regmap, MESON_SAR_ADC_REG0, ®val);
+
+ return FIELD_GET(MESON_SAR_ADC_REG0_FIFO_COUNT_MASK, regval);
+}
+
+static int meson_saradc_lock(struct meson_saradc_priv *priv)
+{
+ uint val, timeout = 10000;
+
+ /* prevent BL30 from using the SAR ADC while we are using it */
+ regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELAY,
+ MESON_SAR_ADC_DELAY_KERNEL_BUSY,
+ MESON_SAR_ADC_DELAY_KERNEL_BUSY);
+
+ /*
+ * wait until BL30 releases it's lock (so we can use the SAR ADC)
+ */
+ do {
+ udelay(1);
+ regmap_read(priv->regmap, MESON_SAR_ADC_DELAY, &val);
+ } while (val & MESON_SAR_ADC_DELAY_BL30_BUSY && timeout--);
+
+ if (timeout < 0) {
+ printf("Timeout while waiting for BL30 unlock\n");
+ return -ETIMEDOUT;
+ }
+
+ return 0;
+}
+
+static void meson_saradc_unlock(struct meson_saradc_priv *priv)
+{
+ /* allow BL30 to use the SAR ADC again */
+ regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELAY,
+ MESON_SAR_ADC_DELAY_KERNEL_BUSY, 0);
+}
+
+static void meson_saradc_clear_fifo(struct meson_saradc_priv *priv)
+{
+ unsigned int count, tmp;
+
+ for (count = 0; count < MESON_SAR_ADC_MAX_FIFO_SIZE; count++) {
+ if (!meson_saradc_get_fifo_count(priv))
+ break;
+
+ regmap_read(priv->regmap, MESON_SAR_ADC_FIFO_RD, &tmp);
+ }
+}
+
+static int meson_saradc_calib_val(struct meson_saradc_priv *priv, int val)
+{
+ int tmp;
+
+ /* use val_calib = scale * val_raw + offset calibration function */
+ tmp = div_s64((s64)val * priv->calibscale, MILLION) + priv->calibbias;
+
+ return clamp(tmp, 0, (1 << priv->data->num_bits) - 1);
+}
+
+static int meson_saradc_wait_busy_clear(struct meson_saradc_priv *priv)
+{
+ uint regval, timeout = 10000;
+
+ /*
+ * NOTE: we need a small delay before reading the status, otherwise
+ * the sample engine may not have started internally (which would
+ * seem to us that sampling is already finished).
+ */
+ do {
+ udelay(1);
+ regmap_read(priv->regmap, MESON_SAR_ADC_REG0, ®val);
+ } while (FIELD_GET(MESON_SAR_ADC_REG0_BUSY_MASK, regval) && timeout--);
+
+ if (timeout < 0)
+ return -ETIMEDOUT;
+
+ return 0;
+}
+
+static int meson_saradc_read_raw_sample(struct meson_saradc_priv *priv,
+ unsigned int channel, uint *val)
+{
+ uint regval, fifo_chan, fifo_val, count;
+ int ret;
+
+ ret = meson_saradc_wait_busy_clear(priv);
+ if (ret)
+ return ret;
+
+ count = meson_saradc_get_fifo_count(priv);
+ if (count != 1) {
+ printf("ADC FIFO has %d element(s) instead of one\n", count);
+ return -EINVAL;
+ }
+
+ regmap_read(priv->regmap, MESON_SAR_ADC_FIFO_RD, ®val);
+ fifo_chan = FIELD_GET(MESON_SAR_ADC_FIFO_RD_CHAN_ID_MASK, regval);
+ if (fifo_chan != channel) {
+ printf("ADC FIFO entry belongs to channel %d instead of %d\n",
+ fifo_chan, channel);
+ return -EINVAL;
+ }
+
+ fifo_val = FIELD_GET(MESON_SAR_ADC_FIFO_RD_SAMPLE_VALUE_MASK, regval);
+ fifo_val &= GENMASK(priv->data->num_bits - 1, 0);
+ *val = meson_saradc_calib_val(priv, fifo_val);
+
+ return 0;
+}
+
+static void meson_saradc_start_sample_engine(struct meson_saradc_priv *priv)
+{
+ regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
+ MESON_SAR_ADC_REG0_FIFO_IRQ_EN,
+ MESON_SAR_ADC_REG0_FIFO_IRQ_EN);
+
+ regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
+ MESON_SAR_ADC_REG0_SAMPLE_ENGINE_ENABLE,
+ MESON_SAR_ADC_REG0_SAMPLE_ENGINE_ENABLE);
+
+ regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
+ MESON_SAR_ADC_REG0_SAMPLING_START,
+ MESON_SAR_ADC_REG0_SAMPLING_START);
+}
+
+static void meson_saradc_stop_sample_engine(struct meson_saradc_priv *priv)
+{
+ regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
+ MESON_SAR_ADC_REG0_FIFO_IRQ_EN, 0);
+
+ regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
+ MESON_SAR_ADC_REG0_SAMPLING_STOP,
+ MESON_SAR_ADC_REG0_SAMPLING_STOP);
+
+ /* wait until all modules are stopped */
+ meson_saradc_wait_busy_clear(priv);
+
+ regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
+ MESON_SAR_ADC_REG0_SAMPLE_ENGINE_ENABLE, 0);
+}
+
+enum meson_saradc_avg_mode {
+ NO_AVERAGING = 0x0,
+ MEAN_AVERAGING = 0x1,
+ MEDIAN_AVERAGING = 0x2,
+};
+
+enum meson_saradc_num_samples {
+ ONE_SAMPLE = 0x0,
+ TWO_SAMPLES = 0x1,
+ FOUR_SAMPLES = 0x2,
+ EIGHT_SAMPLES = 0x3,
+};
+
+static void meson_saradc_set_averaging(struct meson_saradc_priv *priv,
+ unsigned int channel,
+ enum meson_saradc_avg_mode mode,
+ enum meson_saradc_num_samples samples)
+{
+ int val;
+
+ val = samples << MESON_SAR_ADC_AVG_CNTL_NUM_SAMPLES_SHIFT(channel);
+ regmap_update_bits(priv->regmap, MESON_SAR_ADC_AVG_CNTL,
+ MESON_SAR_ADC_AVG_CNTL_NUM_SAMPLES_MASK(channel),
+ val);
+
+ val = mode << MESON_SAR_ADC_AVG_CNTL_AVG_MODE_SHIFT(channel);
+ regmap_update_bits(priv->regmap, MESON_SAR_ADC_AVG_CNTL,
+ MESON_SAR_ADC_AVG_CNTL_AVG_MODE_MASK(channel), val);
+}
+
+static void meson_saradc_enable_channel(struct meson_saradc_priv *priv,
+ unsigned int channel)
+{
+ uint regval;
+
+ /*
+ * the SAR ADC engine allows sampling multiple channels at the same
+ * time. to keep it simple we're only working with one *internal*
+ * channel, which starts counting at index 0 (which means: count = 1).
+ */
+ regval = FIELD_PREP(MESON_SAR_ADC_CHAN_LIST_MAX_INDEX_MASK, 0);
+ regmap_update_bits(priv->regmap, MESON_SAR_ADC_CHAN_LIST,
+ MESON_SAR_ADC_CHAN_LIST_MAX_INDEX_MASK, regval);
+
+ /* map channel index 0 to the channel which we want to read */
+ regval = FIELD_PREP(MESON_SAR_ADC_CHAN_LIST_ENTRY_MASK(0), channel);
+ regmap_update_bits(priv->regmap, MESON_SAR_ADC_CHAN_LIST,
+ MESON_SAR_ADC_CHAN_LIST_ENTRY_MASK(0), regval);
+
+ regval = FIELD_PREP(MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_MUX_MASK,
+ channel);
+ regmap_update_bits(priv->regmap, MESON_SAR_ADC_DETECT_IDLE_SW,
+ MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_MUX_MASK,
+ regval);
+
+ regval = FIELD_PREP(MESON_SAR_ADC_DETECT_IDLE_SW_IDLE_MUX_SEL_MASK,
+ channel);
+ regmap_update_bits(priv->regmap, MESON_SAR_ADC_DETECT_IDLE_SW,
+ MESON_SAR_ADC_DETECT_IDLE_SW_IDLE_MUX_SEL_MASK,
+ regval);
+
+ if (channel == 6)
+ regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELTA_10,
+ MESON_SAR_ADC_DELTA_10_TEMP_SEL, 0);
+}
+
+static int meson_saradc_get_sample(struct meson_saradc_priv *priv,
+ int chan, uint *val)
+{
+ int ret;
+
+ ret = meson_saradc_lock(priv);
+ if (ret)
+ return ret;
+
+ /* clear the FIFO to make sure we're not reading old values */
+ meson_saradc_clear_fifo(priv);
+
+ meson_saradc_set_averaging(priv, chan, MEAN_AVERAGING, EIGHT_SAMPLES);
+
+ meson_saradc_enable_channel(priv, chan);
+
+ meson_saradc_start_sample_engine(priv);
+ ret = meson_saradc_read_raw_sample(priv, chan, val);
+ meson_saradc_stop_sample_engine(priv);
+
+ meson_saradc_unlock(priv);
+
+ if (ret) {
+ printf("failed to read sample for channel %d: %d\n",
+ chan, ret);
+ return ret;
+ }
+
+ return 0;
+}
+
+static int meson_saradc_channel_data(struct udevice *dev, int channel,
+ unsigned int *data)
+{
+ struct meson_saradc_priv *priv = dev_get_priv(dev);
+
+ if (channel != priv->active_channel) {
+ pr_err("Requested channel is not active!");
+ return -EINVAL;
+ }
+
+ return meson_saradc_get_sample(priv, channel, data);
+}
+
+enum meson_saradc_chan7_mux_sel {
+ CHAN7_MUX_VSS = 0x0,
+ CHAN7_MUX_VDD_DIV4 = 0x1,
+ CHAN7_MUX_VDD_DIV2 = 0x2,
+ CHAN7_MUX_VDD_MUL3_DIV4 = 0x3,
+ CHAN7_MUX_VDD = 0x4,
+ CHAN7_MUX_CH7_INPUT = 0x7,
+};
+
+static void meson_saradc_set_chan7_mux(struct meson_saradc_priv *priv,
+ enum meson_saradc_chan7_mux_sel sel)
+{
+ u32 regval;
+
+ regval = FIELD_PREP(MESON_SAR_ADC_REG3_CTRL_CHAN7_MUX_SEL_MASK, sel);
+ regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG3,
+ MESON_SAR_ADC_REG3_CTRL_CHAN7_MUX_SEL_MASK, regval);
+
+ udelay(20);
+}
+
+static int meson_saradc_calib(struct meson_saradc_priv *priv)
+{
+ uint nominal0, nominal1, value0, value1;
+ int ret;
+
+ /* use points 25% and 75% for calibration */
+ nominal0 = (1 << priv->data->num_bits) / 4;
+ nominal1 = (1 << priv->data->num_bits) * 3 / 4;
+
+ meson_saradc_set_chan7_mux(priv, CHAN7_MUX_VDD_DIV4);
+ udelay(20);
+ ret = meson_saradc_get_sample(priv, 7, &value0);
+ if (ret < 0)
+ goto out;
+
+ meson_saradc_set_chan7_mux(priv, CHAN7_MUX_VDD_MUL3_DIV4);
+ udelay(20);
+ ret = meson_saradc_get_sample(priv, 7, &value1);
+ if (ret < 0)
+ goto out;
+
+ if (value1 <= value0) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ priv->calibscale = div_s64((nominal1 - nominal0) * (s64)MILLION,
+ value1 - value0);
+ priv->calibbias = nominal0 - div_s64((s64)value0 * priv->calibscale,
+ MILLION);
+ ret = 0;
+out:
+ meson_saradc_set_chan7_mux(priv, CHAN7_MUX_CH7_INPUT);
+
+ return ret;
+}
+
+static int meson_saradc_init(struct meson_saradc_priv *priv)
+{
+ uint regval;
+ int ret, i;
+
+ priv->calibscale = MILLION;
+
+ /*
+ * make sure we start at CH7 input since the other muxes are only used
+ * for internal calibration.
+ */
+ meson_saradc_set_chan7_mux(priv, CHAN7_MUX_CH7_INPUT);
+
+ /*
+ * leave sampling delay and the input clocks as configured by
+ * BL30 to make sure BL30 gets the values it expects when
+ * reading the temperature sensor.
+ */
+ regmap_read(priv->regmap, MESON_SAR_ADC_REG3, ®val);
+ if (regval & MESON_SAR_ADC_REG3_BL30_INITIALIZED)
+ return 0;
+
+ meson_saradc_stop_sample_engine(priv);
+
+ /* update the channel 6 MUX to select the temperature sensor */
+ regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
+ MESON_SAR_ADC_REG0_ADC_TEMP_SEN_SEL,
+ MESON_SAR_ADC_REG0_ADC_TEMP_SEN_SEL);
+
+ /* disable all channels by default */
+ regmap_write(priv->regmap, MESON_SAR_ADC_CHAN_LIST, 0x0);
+
+ regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG3,
+ MESON_SAR_ADC_REG3_CTRL_SAMPLING_CLOCK_PHASE, 0);
+ regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG3,
+ MESON_SAR_ADC_REG3_CNTL_USE_SC_DLY,
+ MESON_SAR_ADC_REG3_CNTL_USE_SC_DLY);
+
+ /* delay between two samples = (10+1) * 1uS */
+ regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELAY,
+ MESON_SAR_ADC_DELAY_INPUT_DLY_CNT_MASK,
+ FIELD_PREP(MESON_SAR_ADC_DELAY_SAMPLE_DLY_CNT_MASK,
+ 10));
+ regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELAY,
+ MESON_SAR_ADC_DELAY_SAMPLE_DLY_SEL_MASK,
+ FIELD_PREP(MESON_SAR_ADC_DELAY_SAMPLE_DLY_SEL_MASK,
+ 0));
+
+ /* delay between two samples = (10+1) * 1uS */
+ regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELAY,
+ MESON_SAR_ADC_DELAY_INPUT_DLY_CNT_MASK,
+ FIELD_PREP(MESON_SAR_ADC_DELAY_INPUT_DLY_CNT_MASK,
+ 10));
+ regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELAY,
+ MESON_SAR_ADC_DELAY_INPUT_DLY_SEL_MASK,
+ FIELD_PREP(MESON_SAR_ADC_DELAY_INPUT_DLY_SEL_MASK,
+ 1));
+
+ /*
+ * set up the input channel muxes in MESON_SAR_ADC_CHAN_10_SW
+ * (0 = SAR_ADC_CH0, 1 = SAR_ADC_CH1)
+ */
+ regval = FIELD_PREP(MESON_SAR_ADC_CHAN_10_SW_CHAN0_MUX_SEL_MASK, 0);
+ regmap_update_bits(priv->regmap, MESON_SAR_ADC_CHAN_10_SW,
+ MESON_SAR_ADC_CHAN_10_SW_CHAN0_MUX_SEL_MASK,
+ regval);
+ regval = FIELD_PREP(MESON_SAR_ADC_CHAN_10_SW_CHAN1_MUX_SEL_MASK, 1);
+ regmap_update_bits(priv->regmap, MESON_SAR_ADC_CHAN_10_SW,
+ MESON_SAR_ADC_CHAN_10_SW_CHAN1_MUX_SEL_MASK,
+ regval);
+
+ /*
+ * set up the input channel muxes in MESON_SAR_ADC_AUX_SW
+ * (2 = SAR_ADC_CH2, 3 = SAR_ADC_CH3, ...) and enable
+ * MESON_SAR_ADC_AUX_SW_YP_DRIVE_SW and
+ * MESON_SAR_ADC_AUX_SW_XP_DRIVE_SW like the vendor driver.
+ */
+ regval = 0;
+ for (i = 2; i <= 7; i++)
+ regval |= i << MESON_SAR_ADC_AUX_SW_MUX_SEL_CHAN_SHIFT(i);
+ regval |= MESON_SAR_ADC_AUX_SW_YP_DRIVE_SW;
+ regval |= MESON_SAR_ADC_AUX_SW_XP_DRIVE_SW;
+ regmap_write(priv->regmap, MESON_SAR_ADC_AUX_SW, regval);
+
+ ret = meson_saradc_lock(priv);
+ if (ret)
+ return ret;
+
+#if CONFIG_IS_ENABLED(CLK)
+ ret = clk_enable(&priv->core_clk);
+ if (ret)
+ return ret;
+#endif
+
+ regval = FIELD_PREP(MESON_SAR_ADC_REG0_FIFO_CNT_IRQ_MASK, 1);
+ regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
+ MESON_SAR_ADC_REG0_FIFO_CNT_IRQ_MASK, regval);
+
+ regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG11,
+ MESON_SAR_ADC_REG11_BANDGAP_EN,
+ MESON_SAR_ADC_REG11_BANDGAP_EN);
+
+ regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG3,
+ MESON_SAR_ADC_REG3_ADC_EN,
+ MESON_SAR_ADC_REG3_ADC_EN);
+
+ udelay(5);
+
+#if CONFIG_IS_ENABLED(CLK)
+ ret = clk_enable(&priv->adc_clk);
+ if (ret)
+ return ret;
+#endif
+
+ meson_saradc_unlock(priv);
+
+ ret = meson_saradc_calib(priv);
+ if (ret) {
+ printf("calibration failed\n");
+ return -EIO;
+ }
+
+ return 0;
+}
+
+static int meson_saradc_start_channel(struct udevice *dev, int channel)
+{
+ struct meson_saradc_priv *priv = dev_get_priv(dev);
+
+ if (channel < 0 || channel >= NUM_CHANNELS) {
+ printf("Requested channel is invalid!");
+ return -EINVAL;
+ }
+
+ if (!priv->initialized) {
+ int ret;
+
+ ret = meson_saradc_init(priv);
+ if (ret)
+ return ret;
+
+ priv->initialized = true;
+ }
+
+ priv->active_channel = channel;
+
+ return 0;
+}
+
+static int meson_saradc_stop(struct udevice *dev)
+{
+ struct meson_saradc_priv *priv = dev_get_priv(dev);
+
+ priv->active_channel = -1;
+
+ return 0;
+}
+
+static int meson_saradc_probe(struct udevice *dev)
+{
+ struct meson_saradc_priv *priv = dev_get_priv(dev);
+ int ret;
+
+ ret = regmap_init_mem(dev, &priv->regmap);
+ if (ret)
+ return ret;
+
+#if CONFIG_IS_ENABLED(CLK)
+ ret = clk_get_by_name(dev, "core", &priv->core_clk);
+ if (ret)
+ return ret;
+
+ ret = clk_get_by_name(dev, "adc_clk", &priv->adc_clk);
+ if (ret)
+ return ret;
+#endif
+
+ priv->active_channel = -1;
+
+ return 0;
+}
+
+int meson_saradc_ofdata_to_platdata(struct udevice *dev)
+{
+ struct adc_uclass_platdata *uc_pdata = dev_get_uclass_platdata(dev);
+ struct meson_saradc_priv *priv = dev_get_priv(dev);
+
+ priv->data = (struct meson_saradc_data *)dev_get_driver_data(dev);
+
+ uc_pdata->data_mask = GENMASK(priv->data->num_bits - 1, 0);
+ uc_pdata->data_format = ADC_DATA_FORMAT_BIN;
+ uc_pdata->data_timeout_us = MESON_SAR_ADC_TIMEOUT * 1000;
+ uc_pdata->channel_mask = GENMASK(NUM_CHANNELS - 1, 0);
+
+ return 0;
+}
+
+static const struct adc_ops meson_saradc_ops = {
+ .start_channel = meson_saradc_start_channel,
+ .channel_data = meson_saradc_channel_data,
+ .stop = meson_saradc_stop,
+};
+
+static const struct meson_saradc_data gxbb_saradc_data = {
+ .num_bits = 10,
+};
+
+static const struct meson_saradc_data gxl_saradc_data = {
+ .num_bits = 12,
+};
+
+static const struct udevice_id meson_saradc_ids[] = {
+ { .compatible = "amlogic,meson-gxbb-saradc",
+ .data = (ulong)&gxbb_saradc_data },
+ { .compatible = "amlogic,meson-gxl-saradc",
+ .data = (ulong)&gxl_saradc_data },
+ { .compatible = "amlogic,meson-gxm-saradc",
+ .data = (ulong)&gxl_saradc_data },
+ { }
+};
+
+U_BOOT_DRIVER(meson_saradc) = {
+ .name = "meson_saradc",
+ .id = UCLASS_ADC,
+ .of_match = meson_saradc_ids,
+ .ops = &meson_saradc_ops,
+ .probe = meson_saradc_probe,
+ .ofdata_to_platdata = meson_saradc_ofdata_to_platdata,
+ .priv_auto_alloc_size = sizeof(struct meson_saradc_priv),
+};
--
2.7.4
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