From: Przemyslaw Marczak
Date: Tue, 27 Oct 2015 12:08:01 +0000 (+0100)
Subject: dm: adc: add Exynos54xx compatible ADC driver
X-Git-Tag: v2016.01-rc1~110^2~14
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=3b3ad9015e95ccad1a06e2eed1f182c8ddc36b21;p=platform%2Fkernel%2Fu-boot.git
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
---
diff --git a/arch/arm/mach-exynos/include/mach/adc.h b/arch/arm/mach-exynos/include/mach/adc.h
index a0e26d7..9af51ab 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 b6e226a..223b65e 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 c4d9618..eb85b8b 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 0000000..534e68d
--- /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),
+};