This driver works with the ADC on i.MX6SLX, i.MX6UL and i.MX6ULL.
Port the Linux v6.4 driver of the peripheral to make them usable in
barebox.
Signed-off-by: Christian Eggers <ceggers@xxxxxxx>
---
This port has been heavily inspired by the imx7d_adc driver,
ported by Ahmad Fatoum.
drivers/aiodev/Kconfig | 7 +
drivers/aiodev/Makefile | 1 +
drivers/aiodev/vf610_adc.c | 620 +++++++++++++++++++++++++++++++++++++
3 files changed, 628 insertions(+)
create mode 100644 drivers/aiodev/vf610_adc.c
diff --git a/drivers/aiodev/Kconfig b/drivers/aiodev/Kconfig
index 5c8706ffef4a..e1edc25320f3 100644
--- a/drivers/aiodev/Kconfig
+++ b/drivers/aiodev/Kconfig
@@ -73,4 +73,11 @@ config IMX7D_ADC
help
Say yes here to build support for IMX7D ADC.
+config VF610_ADC
+ tristate "Freescale vf610 ADC driver"
+ depends on ARCH_IMX6 || COMPILE_TEST
+ help
+ Say yes here to support for Vybrid board analog-to-digital converter.
+ Since the IP is used for i.MX6SLX, the driver also support i.MX6SLX.
+
endif
diff --git a/drivers/aiodev/Makefile b/drivers/aiodev/Makefile
index 9cb11605ed09..ce95d5be2fb6 100644
--- a/drivers/aiodev/Makefile
+++ b/drivers/aiodev/Makefile
@@ -10,3 +10,4 @@ obj-$(CONFIG_AM335X_ADC) += am335x_adc.o
obj-$(CONFIG_STM32_ADC) += stm32-adc.o stm32-adc-core.o
obj-$(CONFIG_ROCKCHIP_SARADC) += rockchip_saradc.o
obj-$(CONFIG_IMX7D_ADC) += imx7d_adc.o
+obj-$(CONFIG_VF610_ADC) += vf610_adc.o
diff --git a/drivers/aiodev/vf610_adc.c b/drivers/aiodev/vf610_adc.c
new file mode 100644
index 000000000000..cb062e08460e
--- /dev/null
+++ b/drivers/aiodev/vf610_adc.c
@@ -0,0 +1,620 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Freescale Vybrid vf610 ADC driver
+ *
+ * Copyright 2013 Freescale Semiconductor, Inc.
+ */
+
+#include <clock.h>
+#include <io.h>
+#include <linux/printk.h>
+#include <driver.h>
+#include <init.h>
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/clk.h>
+#include <regulator.h>
+#include <linux/err.h>
+
+#include <aiodev.h>
+
+/* This will be the driver name the kernel reports */
+#define DRIVER_NAME "vf610-adc"
+
+/* Vybrid/IMX ADC registers */
+#define VF610_REG_ADC_HC0 0x00
+#define VF610_REG_ADC_HS 0x08
+#define VF610_REG_ADC_R0 0x0c
+#define VF610_REG_ADC_CFG 0x14
+#define VF610_REG_ADC_GC 0x18
+#define VF610_REG_ADC_GS 0x1c
+
+/* Configuration register field define */
+#define VF610_ADC_MODE_BIT8 0x00
+#define VF610_ADC_MODE_BIT10 0x04
+#define VF610_ADC_MODE_BIT12 0x08
+#define VF610_ADC_MODE_MASK 0x0c
+#define VF610_ADC_BUSCLK2_SEL 0x01
+#define VF610_ADC_ALTCLK_SEL 0x02
+#define VF610_ADC_ADACK_SEL 0x03
+#define VF610_ADC_ADCCLK_MASK 0x03
+#define VF610_ADC_CLK_DIV2 0x20
+#define VF610_ADC_CLK_DIV4 0x40
+#define VF610_ADC_CLK_DIV8 0x60
+#define VF610_ADC_CLK_MASK 0x60
+#define VF610_ADC_ADLSMP_LONG 0x10
+#define VF610_ADC_ADSTS_SHORT 0x100
+#define VF610_ADC_ADSTS_NORMAL 0x200
+#define VF610_ADC_ADSTS_LONG 0x300
+#define VF610_ADC_ADSTS_MASK 0x300
+#define VF610_ADC_ADLPC_EN 0x80
+#define VF610_ADC_ADHSC_EN 0x400
+#define VF610_ADC_REFSEL_VALT 0x800
+#define VF610_ADC_REFSEL_VBG 0x1000
+#define VF610_ADC_AVGS_8 0x4000
+#define VF610_ADC_AVGS_16 0x8000
+#define VF610_ADC_AVGS_32 0xC000
+#define VF610_ADC_AVGS_MASK 0xC000
+#define VF610_ADC_OVWREN 0x10000
+
+/* General control register field define */
+#define VF610_ADC_AVGEN 0x20
+#define VF610_ADC_CAL 0x80
+
+/* Other field define */
+#define VF610_ADC_ADCHC(x) ((x) & 0x1F)
+#define VF610_ADC_CONV_DISABLE 0x1F
+#define VF610_ADC_HS_COCO0 0x1
+#define VF610_ADC_CALF 0x2
+#define VF610_ADC_TIMEOUT_NSEC (100 * NSEC_PER_MSEC)
+
+#define DEFAULT_SAMPLE_TIME 1000
+
+enum clk_sel {
+ VF610_ADCIOC_BUSCLK_SET,
+ VF610_ADCIOC_ALTCLK_SET,
+ VF610_ADCIOC_ADACK_SET,
+};
+
+enum vol_ref {
+ VF610_ADCIOC_VR_VREF_SET,
+ VF610_ADCIOC_VR_VALT_SET,
+ VF610_ADCIOC_VR_VBG_SET,
+};
+
+enum average_sel {
+ VF610_ADC_SAMPLE_1,
+ VF610_ADC_SAMPLE_4,
+ VF610_ADC_SAMPLE_8,
+ VF610_ADC_SAMPLE_16,
+ VF610_ADC_SAMPLE_32,
+};
+
+enum conversion_mode_sel {
+ VF610_ADC_CONV_NORMAL,
+ VF610_ADC_CONV_HIGH_SPEED,
+ VF610_ADC_CONV_LOW_POWER,
+};
+
+enum lst_adder_sel {
+ VF610_ADCK_CYCLES_3,
+ VF610_ADCK_CYCLES_5,
+ VF610_ADCK_CYCLES_7,
+ VF610_ADCK_CYCLES_9,
+ VF610_ADCK_CYCLES_13,
+ VF610_ADCK_CYCLES_17,
+ VF610_ADCK_CYCLES_21,
+ VF610_ADCK_CYCLES_25,
+};
+
+struct vf610_adc_feature {
+ enum clk_sel clk_sel;
+ enum vol_ref vol_ref;
+ enum conversion_mode_sel conv_mode;
+
+ int clk_div;
+ int sample_rate;
+ int res_mode;
+ u32 lst_adder_index;
+ u32 default_sample_time;
+
+ bool calibration;
+ bool ovwren;
+};
+
+struct vf610_adc {
+ struct device *dev;
+ void __iomem *regs;
+ struct clk *clk;
+ struct aiodevice aiodev;
+ void (*aiodev_info)(struct device *);
+
+ u32 vref_uv;
+ u32 value;
+ struct regulator *vref;
+
+ u32 max_adck_rate[3];
+ struct vf610_adc_feature adc_feature;
+
+ u32 sample_freq_avail[5];
+
+ struct aiochannel aiochan[16];
+};
+
+static const u32 vf610_hw_avgs[] = { 1, 4, 8, 16, 32 };
+static const u32 vf610_lst_adder[] = { 3, 5, 7, 9, 13, 17, 21, 25 };
+
+static inline void vf610_adc_calculate_rates(struct vf610_adc *info)
+{
+ struct vf610_adc_feature *adc_feature = &info->adc_feature;
+ unsigned long adck_rate, ipg_rate = clk_get_rate(info->clk);
+ u32 adck_period, lst_addr_min;
+ int divisor, i;
+
+ adck_rate = info->max_adck_rate[adc_feature->conv_mode];
+
+ if (adck_rate) {
+ /* calculate clk divider which is within specification */
+ divisor = ipg_rate / adck_rate;
+ adc_feature->clk_div = 1 << fls(divisor + 1);
+ } else {
+ /* fall-back value using a safe divisor */
+ adc_feature->clk_div = 8;
+ }
+
+ adck_rate = ipg_rate / adc_feature->clk_div;
+
+ /*
+ * Determine the long sample time adder value to be used based
+ * on the default minimum sample time provided.
+ */
+ adck_period = NSEC_PER_SEC / adck_rate;
+ lst_addr_min = adc_feature->default_sample_time / adck_period;
+ for (i = 0; i < ARRAY_SIZE(vf610_lst_adder); i++) {
+ if (vf610_lst_adder[i] > lst_addr_min) {
+ adc_feature->lst_adder_index = i;
+ break;
+ }
+ }
+
+ /*
+ * Calculate ADC sample frequencies
+ * Sample time unit is ADCK cycles. ADCK clk source is ipg clock,
+ * which is the same as bus clock.
+ *
+ * ADC conversion time = SFCAdder + AverageNum x (BCT + LSTAdder)
+ * SFCAdder: fixed to 6 ADCK cycles
+ * AverageNum: 1, 4, 8, 16, 32 samples for hardware average.
+ * BCT (Base Conversion Time): fixed to 25 ADCK cycles for 12 bit mode
+ * LSTAdder(Long Sample Time): 3, 5, 7, 9, 13, 17, 21, 25 ADCK cycles
+ */
+ for (i = 0; i < ARRAY_SIZE(vf610_hw_avgs); i++)
+ info->sample_freq_avail[i] =
+ adck_rate / (6 + vf610_hw_avgs[i] *
+ (25 + vf610_lst_adder[adc_feature->lst_adder_index]));
+}
+
+static inline void vf610_adc_cfg_init(struct vf610_adc *info)
+{
+ struct vf610_adc_feature *adc_feature = &info->adc_feature;
+
+ /* set default Configuration for ADC controller */
+ adc_feature->clk_sel = VF610_ADCIOC_BUSCLK_SET;
+ adc_feature->vol_ref = VF610_ADCIOC_VR_VREF_SET;
+
+ adc_feature->calibration = true;
+ adc_feature->ovwren = true;
+
+ adc_feature->res_mode = 12;
+ adc_feature->sample_rate = 1;
+
+ adc_feature->conv_mode = VF610_ADC_CONV_LOW_POWER;
+
+ vf610_adc_calculate_rates(info);
+}
+
+static void vf610_adc_cfg_post_set(struct vf610_adc *info)
+{
+ struct vf610_adc_feature *adc_feature = &info->adc_feature;
+ int cfg_data = 0;
+ int gc_data = 0;
+
+ switch (adc_feature->clk_sel) {
+ case VF610_ADCIOC_ALTCLK_SET:
+ cfg_data |= VF610_ADC_ALTCLK_SEL;
+ break;
+ case VF610_ADCIOC_ADACK_SET:
+ cfg_data |= VF610_ADC_ADACK_SEL;
+ break;
+ default:
+ break;
+ }
+
+ /* low power set for calibration */
+ cfg_data |= VF610_ADC_ADLPC_EN;
+
+ /* enable high speed for calibration */
+ cfg_data |= VF610_ADC_ADHSC_EN;
+
+ /* voltage reference */
+ switch (adc_feature->vol_ref) {
+ case VF610_ADCIOC_VR_VREF_SET:
+ break;
+ case VF610_ADCIOC_VR_VALT_SET:
+ cfg_data |= VF610_ADC_REFSEL_VALT;
+ break;
+ case VF610_ADCIOC_VR_VBG_SET:
+ cfg_data |= VF610_ADC_REFSEL_VBG;
+ break;
+ default:
+ dev_err(info->dev, "error voltage reference\n");
+ }
+
+ /* data overwrite enable */
+ if (adc_feature->ovwren)
+ cfg_data |= VF610_ADC_OVWREN;
+
+ writel(cfg_data, info->regs + VF610_REG_ADC_CFG);
+ writel(gc_data, info->regs + VF610_REG_ADC_GC);
+}
+
+static void vf610_adc_calibration(struct vf610_adc *info)
+{
+ int adc_gc, hc_cfg;
+ u64 start;
+ int coco;
+
+ if (!info->adc_feature.calibration)
+ return;
+
+ hc_cfg = VF610_ADC_CONV_DISABLE;
+ writel(hc_cfg, info->regs + VF610_REG_ADC_HC0);
+
+ adc_gc = readl(info->regs + VF610_REG_ADC_GC);
+ writel(adc_gc | VF610_ADC_CAL, info->regs + VF610_REG_ADC_GC);
+
+ start = get_time_ns();
+ do {
+ if (is_timeout(start, VF610_ADC_TIMEOUT_NSEC)) {
+ dev_err(info->dev, "Timeout for adc calibration\n");
+ break;
+ }
+
+ coco = readl(info->regs + VF610_REG_ADC_HS);
+ } while (!(coco & VF610_ADC_HS_COCO0));
+
+ adc_gc = readl(info->regs + VF610_REG_ADC_GS);
+ if (adc_gc & VF610_ADC_CALF)
+ dev_err(info->dev, "ADC calibration failed\n");
+
+ info->adc_feature.calibration = false;
+}
+
+static void vf610_adc_cfg_set(struct vf610_adc *info)
+{
+ struct vf610_adc_feature *adc_feature = &(info->adc_feature);
+ int cfg_data;
+
+ cfg_data = readl(info->regs + VF610_REG_ADC_CFG);
+
+ cfg_data &= ~VF610_ADC_ADLPC_EN;
+ if (adc_feature->conv_mode == VF610_ADC_CONV_LOW_POWER)
+ cfg_data |= VF610_ADC_ADLPC_EN;
+
+ cfg_data &= ~VF610_ADC_ADHSC_EN;
+ if (adc_feature->conv_mode == VF610_ADC_CONV_HIGH_SPEED)
+ cfg_data |= VF610_ADC_ADHSC_EN;
+
+ writel(cfg_data, info->regs + VF610_REG_ADC_CFG);
+}
+
+static void vf610_adc_sample_set(struct vf610_adc *info)
+{
+ struct vf610_adc_feature *adc_feature = &(info->adc_feature);
+ int cfg_data, gc_data;
+
+ cfg_data = readl(info->regs + VF610_REG_ADC_CFG);
+ gc_data = readl(info->regs + VF610_REG_ADC_GC);
+
+ /* resolution mode */
+ cfg_data &= ~VF610_ADC_MODE_MASK;
+ switch (adc_feature->res_mode) {
+ case 8:
+ cfg_data |= VF610_ADC_MODE_BIT8;
+ break;
+ case 10:
+ cfg_data |= VF610_ADC_MODE_BIT10;
+ break;
+ case 12:
+ cfg_data |= VF610_ADC_MODE_BIT12;
+ break;
+ default:
+ dev_err(info->dev, "error resolution mode\n");
+ break;
+ }
+
+ /* clock select and clock divider */
+ cfg_data &= ~(VF610_ADC_CLK_MASK | VF610_ADC_ADCCLK_MASK);
+ switch (adc_feature->clk_div) {
+ case 1:
+ break;
+ case 2:
+ cfg_data |= VF610_ADC_CLK_DIV2;
+ break;
+ case 4:
+ cfg_data |= VF610_ADC_CLK_DIV4;
+ break;
+ case 8:
+ cfg_data |= VF610_ADC_CLK_DIV8;
+ break;
+ case 16:
+ switch (adc_feature->clk_sel) {
+ case VF610_ADCIOC_BUSCLK_SET:
+ cfg_data |= VF610_ADC_BUSCLK2_SEL | VF610_ADC_CLK_DIV8;
+ break;
+ default:
+ dev_err(info->dev, "error clk divider\n");
+ break;
+ }
+ break;
+ }
+
+ /*
+ * Set ADLSMP and ADSTS based on the Long Sample Time Adder value
+ * determined.
+ */
+ switch (adc_feature->lst_adder_index) {
+ case VF610_ADCK_CYCLES_3:
+ break;
+ case VF610_ADCK_CYCLES_5:
+ cfg_data |= VF610_ADC_ADSTS_SHORT;
+ break;
+ case VF610_ADCK_CYCLES_7:
+ cfg_data |= VF610_ADC_ADSTS_NORMAL;
+ break;
+ case VF610_ADCK_CYCLES_9:
+ cfg_data |= VF610_ADC_ADSTS_LONG;
+ break;
+ case VF610_ADCK_CYCLES_13:
+ cfg_data |= VF610_ADC_ADLSMP_LONG;
+ break;
+ case VF610_ADCK_CYCLES_17:
+ cfg_data |= VF610_ADC_ADLSMP_LONG;
+ cfg_data |= VF610_ADC_ADSTS_SHORT;
+ break;
+ case VF610_ADCK_CYCLES_21:
+ cfg_data |= VF610_ADC_ADLSMP_LONG;
+ cfg_data |= VF610_ADC_ADSTS_NORMAL;
+ break;
+ case VF610_ADCK_CYCLES_25:
+ cfg_data |= VF610_ADC_ADLSMP_LONG;
+ cfg_data |= VF610_ADC_ADSTS_NORMAL;
+ break;
+ default:
+ dev_err(info->dev, "error in sample time select\n");
+ }
+
+ /* update hardware average selection */
+ cfg_data &= ~VF610_ADC_AVGS_MASK;
+ gc_data &= ~VF610_ADC_AVGEN;
+ switch (adc_feature->sample_rate) {
+ case VF610_ADC_SAMPLE_1:
+ break;
+ case VF610_ADC_SAMPLE_4:
+ gc_data |= VF610_ADC_AVGEN;
+ break;
+ case VF610_ADC_SAMPLE_8:
+ gc_data |= VF610_ADC_AVGEN;
+ cfg_data |= VF610_ADC_AVGS_8;
+ break;
+ case VF610_ADC_SAMPLE_16:
+ gc_data |= VF610_ADC_AVGEN;
+ cfg_data |= VF610_ADC_AVGS_16;
+ break;
+ case VF610_ADC_SAMPLE_32:
+ gc_data |= VF610_ADC_AVGEN;
+ cfg_data |= VF610_ADC_AVGS_32;
+ break;
+ default:
+ dev_err(info->dev,
+ "error hardware sample average select\n");
+ }
+
+ writel(cfg_data, info->regs + VF610_REG_ADC_CFG);
+ writel(gc_data, info->regs + VF610_REG_ADC_GC);
+}
+
+static void vf610_adc_hw_init(struct vf610_adc *info)
+{
+ /* CFG: Feature set */
+ vf610_adc_cfg_post_set(info);
+ vf610_adc_sample_set(info);
+
+ /* adc calibration */
+ vf610_adc_calibration(info);
+
+ /* CFG: power and speed set */
+ vf610_adc_cfg_set(info);
+}
+
+static int __vf610_adc_read_data(struct vf610_adc *info)
+{
+ int result;
+
+ result = readl(info->regs + VF610_REG_ADC_R0);
+
+ switch (info->adc_feature.res_mode) {
+ case 8:
+ result &= 0xFF;
+ break;
+ case 10:
+ result &= 0x3FF;
+ break;
+ case 12:
+ result &= 0xFFF;
+ break;
+ default:
+ break;
+ }
+
+ return result;
+}
+
+static int vf610_adc_read_data(struct vf610_adc *info)
+{
+ int coco;
+ int ret = -EAGAIN;
+
+ coco = readl(info->regs + VF610_REG_ADC_HS);
+ if (coco & VF610_ADC_HS_COCO0) {
+ ret = __vf610_adc_read_data(info);
+ }
+
+ return ret;
+}
+
+static int vf610_read_sample(struct aiochannel *chan, int *val)
+{
+ struct vf610_adc *info = container_of(chan->aiodev, struct vf610_adc, aiodev);
+ unsigned int hc_cfg;
+ u64 raw64, start;
+ int ret;
+
+ hc_cfg = VF610_ADC_ADCHC(chan->index & 0x0f);
+ writel(hc_cfg, info->regs + VF610_REG_ADC_HC0);
+
+ start = get_time_ns();
+ do {
+ if (is_timeout(start, VF610_ADC_TIMEOUT_NSEC)) {
+ ret = -ETIMEDOUT;
+ break;
+ }
+
+ ret = vf610_adc_read_data(info);
+ } while (ret == -EAGAIN);
+
+ if (ret < 0)
+ return ret;
+
+ raw64 = ret;
+ raw64 *= info->vref_uv;
+ raw64 = div_u64(raw64, 1000);
+ *val = div_u64(raw64, (1 << 12));
+
+ return 0;
+}
+
+
+static const struct of_device_id vf610_adc_match[] = {
+ { .compatible = "fsl,vf610-adc", },
+ { /* sentinel */ }
+};
+
+static void vf610_adc_devinfo(struct device *dev)
+{
+ struct vf610_adc *info = dev->parent->priv;
+
+ if (info->aiodev_info)
+ info->aiodev_info(dev);
+
+ pr_info("Sample Rate: %u\n", info->sample_freq_avail[info->adc_feature.sample_rate]);
+}
+
+static int vf610_adc_probe(struct device *dev)
+{
+ struct aiodevice *aiodev;
+ struct vf610_adc *info;
+ int ret, i;
+
+ info = xzalloc(sizeof(*info));
+ info->dev = dev;
+
+ info->regs = dev_request_mem_region(dev, 0);
+ if (IS_ERR(info->regs))
+ return PTR_ERR(info->regs);
+
+ info->clk = clk_get(dev, "adc");
+ if (IS_ERR(info->clk)) {
+ dev_err(dev, "failed getting clock, err = %ld\n",
+ PTR_ERR(info->clk));
+ return PTR_ERR(info->clk);
+ }
+
+ info->vref = regulator_get(dev, "vref");
+ if (IS_ERR(info->vref))
+ return PTR_ERR(info->vref);
+
+ of_property_read_u32_array(dev->device_node, "fsl,adck-max-frequency", info->max_adck_rate, 3);
+
+ info->adc_feature.default_sample_time = DEFAULT_SAMPLE_TIME;
+ of_property_read_u32(dev->device_node, "min-sample-time", &info->adc_feature.default_sample_time);
+
+ dev->priv = info;
+ aiodev = &info->aiodev;
+
+ aiodev->num_channels = 16;
+ aiodev->hwdev = dev;
+ aiodev->read = vf610_read_sample;
+ aiodev->channels = xzalloc(aiodev->num_channels * sizeof(aiodev->channels[0]));
+
+ for (i = 0; i < aiodev->num_channels; i++) {
+ aiodev->channels[i] = &info->aiochan[i];
+ info->aiochan[i].unit = "mV";
+ }
+
+ ret = regulator_enable(info->vref);
+ if (ret)
+ return ret;
+
+ info->vref_uv = regulator_get_voltage(info->vref);
+
+ ret = clk_enable(info->clk);
+ if (ret) {
+ dev_err(dev,
+ "Could not prepare or enable the clock.\n");
+ goto error_adc_clk_enable;
+ }
+
+ vf610_adc_cfg_init(info);
+ vf610_adc_hw_init(info);
+
+ ret = aiodevice_register(aiodev);
+ if (ret < 0) {
+ dev_err(dev, "Couldn't register the device.\n");
+ goto error_adc_buffer_init;
+ }
+
+ info->aiodev_info = aiodev->dev.info;
+ aiodev->dev.info = vf610_adc_devinfo;
+
+ return 0;
+
+error_adc_buffer_init:
+ clk_disable(info->clk);
+error_adc_clk_enable:
+ regulator_disable(info->vref);
+
+ return ret;
+}
+
+static void vf610_adc_remove(struct device *dev)
+{
+ struct vf610_adc *info = dev->priv;
+
+ regulator_disable(info->vref);
+ clk_disable(info->clk);
+}
+
+static struct driver vf610_adc_driver = {
+ .probe = vf610_adc_probe,
+ .remove = vf610_adc_remove,
+ .name = DRIVER_NAME,
+ .of_compatible = vf610_adc_match,
+};
+
+device_platform_driver(vf610_adc_driver);
+
+MODULE_AUTHOR("Fugang Duan <B38611@xxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("Freescale VF610 ADC driver");
+MODULE_LICENSE("GPL v2");
--
2.35.3
