From 3b3ad9015e95ccad1a06e2eed1f182c8ddc36b21 Mon Sep 17 00:00:00 2001 From: Przemyslaw Marczak Date: Tue, 27 Oct 2015 13:08:01 +0100 Subject: [PATCH] dm: adc: add Exynos54xx compatible ADC driver This commit adds driver for Exynos54xx ADC subsystem. The driver is implemented using driver model, amd provides ADC uclass's methods for ADC single channel operations: - adc_start_channel() - adc_channel_data() - adc_stop() The basic parameters of ADC conversion, are: - sample rate: 600KSPS - output the data as average of 8 time conversion ADC features: - sample rate: 600KSPS - resolution: 12-bit - channels: 10 (analog multiplexer) Signed-off-by: Przemyslaw Marczak Cc: Minkyu Kang Cc: Simon Glass Signed-off-by: Minkyu Kang --- arch/arm/mach-exynos/include/mach/adc.h | 44 +++++++ drivers/adc/Kconfig | 9 ++ drivers/adc/Makefile | 1 + drivers/adc/exynos-adc.c | 145 ++++++++++++++++++++++++ 4 files changed, 199 insertions(+) create mode 100644 drivers/adc/exynos-adc.c diff --git a/arch/arm/mach-exynos/include/mach/adc.h b/arch/arm/mach-exynos/include/mach/adc.h index a0e26d7052..9af51ab381 100644 --- a/arch/arm/mach-exynos/include/mach/adc.h +++ b/arch/arm/mach-exynos/include/mach/adc.h @@ -9,6 +9,39 @@ #ifndef __ASM_ARM_ARCH_ADC_H_ #define __ASM_ARM_ARCH_ADC_H_ +#define ADC_V2_CON1_SOFT_RESET (0x2 << 1) +#define ADC_V2_CON1_STC_EN 0x1 + +#define ADC_V2_CON2_OSEL(x) (((x) & 0x1) << 10) +#define OSEL_2S 0x0 +#define OSEL_BINARY 0x1 +#define ADC_V2_CON2_ESEL(x) (((x) & 0x1) << 9) +#define ESEL_ADC_EVAL_TIME_40CLK 0x0 +#define ESEL_ADC_EVAL_TIME_20CLK 0x1 +#define ADC_V2_CON2_HIGHF(x) (((x) & 0x1) << 8) +#define HIGHF_CONV_RATE_30KSPS 0x0 +#define HIGHF_CONV_RATE_600KSPS 0x1 +#define ADC_V2_CON2_C_TIME(x) (((x) & 0x7) << 4) +#define ADC_V2_CON2_CHAN_SEL_MASK 0xf +#define ADC_V2_CON2_CHAN_SEL(x) ((x) & ADC_V2_CON2_CHAN_SEL_MASK) + +#define ADC_V2_GET_STATUS_FLAG(x) (((x) >> 2) & 0x1) +#define FLAG_CONV_END 0x1 + +#define ADC_V2_INT_DISABLE 0x0 +#define ADC_V2_INT_ENABLE 0x1 +#define INT_NOT_GENERATED 0x0 +#define INT_GENERATED 0x1 + +#define ADC_V2_VERSION 0x80000008 + +#define ADC_V2_MAX_CHANNEL 9 + +/* For default 8 time convertion with sample rate 600 kSPS - 15us timeout */ +#define ADC_V2_CONV_TIMEOUT_US 15 + +#define ADC_V2_DAT_MASK 0xfff + #ifndef __ASSEMBLY__ struct s5p_adc { unsigned int adccon; @@ -21,6 +54,17 @@ struct s5p_adc { unsigned int adcmux; unsigned int adcclrintpndnup; }; + +struct exynos_adc_v2 { + unsigned int con1; + unsigned int con2; + unsigned int status; + unsigned int dat; + unsigned int int_en; + unsigned int int_status; + unsigned int reserved[2]; + unsigned int version; +}; #endif #endif /* __ASM_ARM_ARCH_ADC_H_ */ diff --git a/drivers/adc/Kconfig b/drivers/adc/Kconfig index b6e226a5c4..223b65eada 100644 --- a/drivers/adc/Kconfig +++ b/drivers/adc/Kconfig @@ -10,3 +10,12 @@ config ADC - methods for get Vdd/Vss reference Voltage values with polarity - support supply's phandle with auto-enable - supply polarity setting in fdt + +config ADC_EXYNOS + bool "Enable Exynos 54xx ADC driver" + help + This enables basic driver for Exynos ADC compatible with Exynos54xx. + It provides: + - 10 analog input channels + - 12-bit resolution + - 600 KSPS of sample rate diff --git a/drivers/adc/Makefile b/drivers/adc/Makefile index c4d9618ec3..eb85b8b1a6 100644 --- a/drivers/adc/Makefile +++ b/drivers/adc/Makefile @@ -6,3 +6,4 @@ # obj-$(CONFIG_ADC) += adc-uclass.o +obj-$(CONFIG_ADC_EXYNOS) += exynos-adc.o diff --git a/drivers/adc/exynos-adc.c b/drivers/adc/exynos-adc.c new file mode 100644 index 0000000000..534e68db8b --- /dev/null +++ b/drivers/adc/exynos-adc.c @@ -0,0 +1,145 @@ +/* + * Copyright (C) 2015 Samsung Electronics + * Przemyslaw Marczak + * + * SPDX-License-Identifier: GPL-2.0+ + */ +#include +#include +#include +#include +#include + +struct exynos_adc_priv { + int active_channel; + struct exynos_adc_v2 *regs; +}; + +int exynos_adc_channel_data(struct udevice *dev, int channel, + unsigned int *data) +{ + struct exynos_adc_priv *priv = dev_get_priv(dev); + struct exynos_adc_v2 *regs = priv->regs; + + if (channel != priv->active_channel) { + error("Requested channel is not active!"); + return -EINVAL; + } + + if (ADC_V2_GET_STATUS_FLAG(readl(®s->status)) != FLAG_CONV_END) + return -EBUSY; + + *data = readl(®s->dat) & ADC_V2_DAT_MASK; + + return 0; +} + +int exynos_adc_start_channel(struct udevice *dev, int channel) +{ + struct exynos_adc_priv *priv = dev_get_priv(dev); + struct exynos_adc_v2 *regs = priv->regs; + unsigned int cfg; + + /* Choose channel */ + cfg = readl(®s->con2); + cfg &= ~ADC_V2_CON2_CHAN_SEL_MASK; + cfg |= ADC_V2_CON2_CHAN_SEL(channel); + writel(cfg, ®s->con2); + + /* Start conversion */ + cfg = readl(®s->con1); + writel(cfg | ADC_V2_CON1_STC_EN, ®s->con1); + + priv->active_channel = channel; + + return 0; +} + +int exynos_adc_stop(struct udevice *dev) +{ + struct exynos_adc_priv *priv = dev_get_priv(dev); + struct exynos_adc_v2 *regs = priv->regs; + unsigned int cfg; + + /* Stop conversion */ + cfg = readl(®s->con1); + cfg |= ~ADC_V2_CON1_STC_EN; + + writel(cfg, ®s->con1); + + priv->active_channel = -1; + + return 0; +} + +int exynos_adc_probe(struct udevice *dev) +{ + struct exynos_adc_priv *priv = dev_get_priv(dev); + struct exynos_adc_v2 *regs = priv->regs; + unsigned int cfg; + + /* Check HW version */ + if (readl(®s->version) != ADC_V2_VERSION) { + error("This driver supports only ADC v2!"); + return -ENXIO; + } + + /* ADC Reset */ + writel(ADC_V2_CON1_SOFT_RESET, ®s->con1); + + /* Disable INT - will read status only */ + writel(0x0, ®s->int_en); + + /* CON2 - set conversion parameters */ + cfg = ADC_V2_CON2_C_TIME(3); /* Conversion times: (1 << 3) = 8 */ + cfg |= ADC_V2_CON2_OSEL(OSEL_BINARY); + cfg |= ADC_V2_CON2_ESEL(ESEL_ADC_EVAL_TIME_20CLK); + cfg |= ADC_V2_CON2_HIGHF(HIGHF_CONV_RATE_600KSPS); + writel(cfg, ®s->con2); + + priv->active_channel = -1; + + return 0; +} + +int exynos_adc_ofdata_to_platdata(struct udevice *dev) +{ + struct adc_uclass_platdata *uc_pdata = dev_get_uclass_platdata(dev); + struct exynos_adc_priv *priv = dev_get_priv(dev); + + priv->regs = (struct exynos_adc_v2 *)dev_get_addr(dev); + if (priv->regs == (struct exynos_adc_v2 *)FDT_ADDR_T_NONE) { + error("Dev: %s - can't get address!", dev->name); + return -ENODATA; + } + + uc_pdata->data_mask = ADC_V2_DAT_MASK; + uc_pdata->data_format = ADC_DATA_FORMAT_BIN; + uc_pdata->data_timeout_us = ADC_V2_CONV_TIMEOUT_US; + + /* Mask available channel bits: [0:9] */ + uc_pdata->channel_mask = (2 << ADC_V2_MAX_CHANNEL) - 1; + + return 0; +} + +static const struct adc_ops exynos_adc_ops = { + .start_channel = exynos_adc_start_channel, + .channel_data = exynos_adc_channel_data, + .stop = exynos_adc_stop, +}; + +static const struct udevice_id exynos_adc_ids[] = { + { .compatible = "samsung,exynos-adc-v2" }, + { } +}; + +U_BOOT_DRIVER(exynos_adc) = { + .name = "exynos-adc", + .id = UCLASS_ADC, + .of_match = exynos_adc_ids, + .ops = &exynos_adc_ops, + .probe = exynos_adc_probe, + .ofdata_to_platdata = exynos_adc_ofdata_to_platdata, + .priv_auto_alloc_size = sizeof(struct exynos_adc_priv), +};