442 lines
12 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Driver for Rockchip Flexbus ADC opmode
*
* Copyright (C) 2024 Rockchip Electronics Co., Ltd.
*/
#include <linux/clk.h>
#include <linux/completion.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/iio/buffer.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/triggered_buffer.h>
#include <linux/iio/trigger_consumer.h>
#include <dt-bindings/mfd/rockchip-flexbus.h>
#include <linux/mfd/rockchip-flexbus.h>
#define FLEXBUS_MAX_RX_RATE 200000000
#define FLEXBUS_ADC_ERR_ISR (FLEXBUS_DMA_TIMEOUT_ISR | FLEXBUS_DMA_ERR_ISR | \
FLEXBUS_RX_UDF_ISR | FLEXBUS_RX_OVF_ISR)
#define FLEXBUS_ADC_ISR (FLEXBUS_ADC_ERR_ISR | FLEXBUS_RX_DONE_ISR)
#define FLEXBUS_ADC_TIMEOUT msecs_to_jiffies(100)
#define FLEXBUS_ADC_REPEAT 0x40
enum flexbus_adc_result {
ADC_DONE = 0,
ADC_ERR,
};
struct rockchip_flexbus_adc;
struct rockchip_flexbus_adc_ops {
int (*read_block)(struct rockchip_flexbus_adc *rkfb_adc, dma_addr_t dst_phys, u32 dst_len,
u32 num_of_dfs);
};
struct rockchip_flexbus_adc {
struct device *dev;
struct rockchip_flexbus *rkfb;
struct clk *ref_clk; /* ref_clk is only used for slave-mode */
u32 dfs;
bool slave_mode;
bool free_sclk;
bool auto_pad;
bool cpol;
bool cpha;
struct mutex lock;
struct completion completion;
enum flexbus_adc_result result;
u32 dst_buf_len;
dma_addr_t dst_buf_phys;
void *dst_buf;
const struct rockchip_flexbus_adc_ops *ops;
};
static const struct iio_chan_spec rockchip_flexbus_adc_channel[] = {
{
.type = IIO_VOLTAGE,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SAMP_FREQ),
.scan_type = {
.sign = 'u',
.realbits = 16,
.storagebits = 16,
.shift = 0,
.repeat = FLEXBUS_ADC_REPEAT,
.endianness = IIO_CPU,
},
},
};
static int rockchip_flexbus_adc_read_block(struct rockchip_flexbus_adc *rkfb_adc,
dma_addr_t dst_phys, u32 dst_len, u32 num_of_dfs)
{
struct rockchip_flexbus *rkfb = rkfb_adc->rkfb;
int ret = 0;
if (num_of_dfs > 0x08000000) {
dev_err(rkfb_adc->dev, "num_of_dfs is too large\n");
return -EINVAL;
}
mutex_lock(&rkfb_adc->lock);
reinit_completion(&rkfb_adc->completion);
rockchip_flexbus_writel(rkfb, FLEXBUS_RX_NUM, num_of_dfs);
rockchip_flexbus_writel(rkfb, FLEXBUS_DMA_DST_ADDR0, (ulong)dst_phys >> 2);
rockchip_flexbus_writel(rkfb, FLEXBUS_DMA_DST_LEN0, dst_len);
rockchip_flexbus_writel(rkfb, FLEXBUS_ENR, FLEXBUS_RX_ENR);
if (!wait_for_completion_timeout(&rkfb_adc->completion, FLEXBUS_ADC_TIMEOUT)) {
ret = -ETIMEDOUT;
goto end;
}
if (rkfb_adc->result != ADC_DONE)
ret = -1;
end:
rockchip_flexbus_writel(rkfb, FLEXBUS_ENR, FLEXBUS_RX_DIS);
mutex_unlock(&rkfb_adc->lock);
return ret;
}
static void rockchip_flexbus_adc_isr(struct rockchip_flexbus *rkfb, u32 isr)
{
struct rockchip_flexbus_adc *rkfb_adc = rkfb->fb1_data;
if (rkfb->opmode1 != ROCKCHIP_FLEXBUS1_OPMODE_ADC)
return;
if (isr & FLEXBUS_RX_DONE_ISR) {
rkfb_adc->result = ADC_DONE;
rockchip_flexbus_writel(rkfb, FLEXBUS_ICR, FLEXBUS_RX_DONE_ISR);
}
if (isr & FLEXBUS_ADC_ERR_ISR) {
rkfb_adc->result = ADC_ERR;
if (isr & FLEXBUS_DMA_TIMEOUT_ISR) {
dev_err_ratelimited(rkfb_adc->dev, "dma timeout!\n");
rockchip_flexbus_writel(rkfb, FLEXBUS_ICR, FLEXBUS_DMA_TIMEOUT_ISR);
}
if (isr & FLEXBUS_DMA_ERR_ISR) {
dev_err_ratelimited(rkfb_adc->dev, "dma err!\n");
rockchip_flexbus_writel(rkfb, FLEXBUS_ICR, FLEXBUS_DMA_ERR_ISR);
}
if (isr & FLEXBUS_RX_UDF_ISR) {
dev_err_ratelimited(rkfb_adc->dev, "rx underflow!\n");
rockchip_flexbus_writel(rkfb, FLEXBUS_ICR, FLEXBUS_RX_UDF_ISR);
}
if (isr & FLEXBUS_RX_OVF_ISR) {
dev_err_ratelimited(rkfb_adc->dev, "rx overflow!\n");
rockchip_flexbus_writel(rkfb, FLEXBUS_ICR, FLEXBUS_RX_OVF_ISR);
}
}
complete(&rkfb_adc->completion);
}
static int rockchip_flexbus_adc_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan, int *val, int *val2,
long mask)
{
struct rockchip_flexbus_adc *rkfb_adc = iio_priv(indio_dev);
u32 val_mask;
int ret;
switch (mask) {
case IIO_CHAN_INFO_RAW:
ret = rkfb_adc->ops->read_block(rkfb_adc, rkfb_adc->dst_buf_phys,
rkfb_adc->dst_buf_len, 8);
if (ret)
return ret;
switch (rkfb_adc->dfs) {
case 4:
val_mask = 0xf;
break;
case 8:
val_mask = 0xff;
break;
case 16:
default:
val_mask = 0xffff;
break;
}
*val = readw(rkfb_adc->dst_buf) & val_mask;
return IIO_VAL_INT;
case IIO_CHAN_INFO_SAMP_FREQ:
if (rkfb_adc->slave_mode && !rkfb_adc->ref_clk) {
dev_err(rkfb_adc->dev,
"sample freq depends on clock source of the ADC device\n");
return -EINVAL;
}
if (rkfb_adc->slave_mode)
*val = clk_get_rate(rkfb_adc->ref_clk);
else
*val = clk_get_rate(rkfb_adc->rkfb->clks[1].clk) / 2;
return IIO_VAL_INT;
default:
return -EINVAL;
}
}
static int rockchip_flexbus_adc_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan, int val, int val2,
long mask)
{
struct rockchip_flexbus_adc *rkfb_adc = iio_priv(indio_dev);
int ret;
switch (mask) {
case IIO_CHAN_INFO_SAMP_FREQ:
if (rkfb_adc->slave_mode && !rkfb_adc->ref_clk) {
dev_err(rkfb_adc->dev,
"sample freq depends on clock source of the ADC device\n");
return -EINVAL;
}
mutex_lock(&rkfb_adc->lock);
if (val > FLEXBUS_MAX_RX_RATE / 2)
val = FLEXBUS_MAX_RX_RATE / 2;
if (rkfb_adc->slave_mode)
ret = clk_set_rate(rkfb_adc->ref_clk, val);
else
ret = clk_set_rate(rkfb_adc->rkfb->clks[1].clk, val * 2);
mutex_unlock(&rkfb_adc->lock);
break;
default:
return -EINVAL;
}
return ret;
}
static const struct iio_info rockchip_flexbus_adc_info = {
.read_raw = rockchip_flexbus_adc_read_raw,
.write_raw = rockchip_flexbus_adc_write_raw,
};
static irqreturn_t rockchip_flexbus_adc_trigger_handler(int irq, void *p)
{
struct iio_poll_func *pf = p;
struct iio_dev *indio_dev = pf->indio_dev;
struct rockchip_flexbus_adc *rkfb_adc = iio_priv(indio_dev);
int ret;
ret = rkfb_adc->ops->read_block(rkfb_adc, rkfb_adc->dst_buf_phys, rkfb_adc->dst_buf_len,
indio_dev->channels->scan_type.repeat);
if (!ret)
iio_push_to_buffers_with_timestamp(indio_dev, rkfb_adc->dst_buf,
iio_get_time_ns(indio_dev));
iio_trigger_notify_done(indio_dev->trig);
return IRQ_HANDLED;
}
static int rockchip_flexbus_adc_init(struct rockchip_flexbus_adc *rkfb_adc)
{
struct rockchip_flexbus *rkfb = rkfb_adc->rkfb;
u32 val;
if (!rkfb_adc->slave_mode && rkfb_adc->free_sclk)
rockchip_flexbus_writel(rkfb, FLEXBUS_FREE_SCLK, FLEXBUS_RX_FREE_MODE);
val = 0x0;
if (rkfb_adc->slave_mode)
val |= FLEXBUS_CLK1_IN;
rockchip_flexbus_writel(rkfb, FLEXBUS_SLAVE_MODE, val);
switch (rkfb_adc->dfs) {
case 4:
val = rkfb->dfs_reg->dfs_4bit;
break;
case 8:
val = rkfb->dfs_reg->dfs_8bit;
break;
case 16:
val = rkfb->dfs_reg->dfs_16bit;
break;
default:
return -EINVAL;
}
if (rkfb_adc->auto_pad)
val |= FLEXBUS_AUTOPAD;
if (rkfb_adc->cpol)
val |= FLEXBUS_CPOL;
if (rkfb_adc->cpha)
val |= FLEXBUS_CPHA;
rockchip_flexbus_writel(rkfb, FLEXBUS_RX_CTL, val);
rockchip_flexbus_setbits(rkfb, FLEXBUS_IMR, FLEXBUS_ADC_ISR);
rkfb->config->grf_config(rkfb, rkfb_adc->slave_mode, rkfb_adc->cpol, rkfb_adc->cpha);
return 0;
}
static int rockchip_flexbus_adc_parse_dt(struct rockchip_flexbus_adc *rkfb_adc)
{
rkfb_adc->slave_mode = device_property_read_bool(rkfb_adc->dev, "rockchip,slave-mode");
rkfb_adc->auto_pad = device_property_read_bool(rkfb_adc->dev, "rockchip,auto-pad");
rkfb_adc->cpol = device_property_read_bool(rkfb_adc->dev, "rockchip,cpol");
rkfb_adc->cpha = device_property_read_bool(rkfb_adc->dev, "rockchip,cpha");
rkfb_adc->free_sclk = device_property_read_bool(rkfb_adc->dev, "rockchip,free-sclk");
if (device_property_read_u32(rkfb_adc->dev, "rockchip,dfs", &rkfb_adc->dfs)) {
dev_err(rkfb_adc->dev, "failed to get dfs\n");
return -EINVAL;
}
if (rkfb_adc->dfs != 4 && rkfb_adc->dfs != 8 && rkfb_adc->dfs != 16) {
dev_err(rkfb_adc->dev, "invalid dfs\n");
return -EINVAL;
}
return 0;
}
static const struct rockchip_flexbus_adc_ops rockchip_flexbus_adc_ops = {
.read_block = rockchip_flexbus_adc_read_block,
};
static const struct of_device_id rockchip_flexbus_adc_of_match[] = {
{ .compatible = "rockchip,flexbus-adc" },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, rockchip_flexbus_adc_of_match);
static int rockchip_flexbus_adc_probe(struct platform_device *pdev)
{
struct rockchip_flexbus *rkfb = dev_get_drvdata(pdev->dev.parent);
struct rockchip_flexbus_adc *rkfb_adc = NULL;
struct iio_dev *indio_dev = NULL;
int ret = 0;
if (rkfb->opmode1 != ROCKCHIP_FLEXBUS1_OPMODE_ADC) {
dev_err(&pdev->dev, "flexbus1 opmode mismatch!\n");
return -ENODEV;
}
indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*rkfb_adc));
if (!indio_dev)
return -ENOMEM;
rkfb_adc = iio_priv(indio_dev);
platform_set_drvdata(pdev, indio_dev);
rkfb_adc->dev = &pdev->dev;
rkfb_adc->rkfb = rkfb;
rockchip_flexbus_set_fb1(rkfb, rkfb_adc, rockchip_flexbus_adc_isr);
ret = rockchip_flexbus_adc_parse_dt(rkfb_adc);
if (ret)
goto err_fb1;
if (rkfb_adc->slave_mode) {
rkfb_adc->ref_clk = devm_clk_get(&pdev->dev, "ref_clk");
if (IS_ERR(rkfb_adc->ref_clk)) {
dev_warn(rkfb_adc->dev,
"failed to get ref_clk in slave-mode. Please make sure the ADC device has clock source.\n");
rkfb_adc->ref_clk = NULL;
} else {
ret = clk_prepare_enable(rkfb_adc->ref_clk);
if (ret) {
dev_err(rkfb_adc->dev, "failed to enable ref_clk.\n");
goto err_fb1;
}
}
}
mutex_init(&rkfb_adc->lock);
init_completion(&rkfb_adc->completion);
indio_dev->name = dev_name(&pdev->dev);
indio_dev->info = &rockchip_flexbus_adc_info;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->channels = rockchip_flexbus_adc_channel;
indio_dev->num_channels = 1;
ret = rockchip_flexbus_adc_init(rkfb_adc);
if (ret)
goto err_mutex_destroy;
rkfb_adc->ops = &rockchip_flexbus_adc_ops;
rkfb_adc->dst_buf_len = DIV_ROUND_UP(indio_dev->channels->scan_type.repeat * rkfb_adc->dfs,
8);
rkfb_adc->dst_buf_len = round_up(rkfb_adc->dst_buf_len, 0x40);
if (rkfb_adc->dst_buf_len < 0x40 || rkfb_adc->dst_buf_len > 0x0fffffc0) {
dev_err(rkfb_adc->dev, "buf_len should >= 0x40 and <= 0x0fffffc0\n");
ret = -EINVAL;
goto err_mutex_destroy;
}
rkfb_adc->dst_buf = dmam_alloc_coherent(rkfb_adc->dev, rkfb_adc->dst_buf_len,
&rkfb_adc->dst_buf_phys, GFP_KERNEL | __GFP_ZERO);
if (!rkfb_adc->dst_buf) {
ret = -ENOMEM;
goto err_mutex_destroy;
}
ret = devm_iio_triggered_buffer_setup(&pdev->dev, indio_dev, &iio_pollfunc_store_time,
&rockchip_flexbus_adc_trigger_handler, NULL);
if (ret)
goto err_mutex_destroy;
ret = devm_iio_device_register(&pdev->dev, indio_dev);
if (ret)
goto err_mutex_destroy;
return ret;
err_mutex_destroy:
mutex_destroy(&rkfb_adc->lock);
if (rkfb_adc->ref_clk)
clk_disable_unprepare(rkfb_adc->ref_clk);
err_fb1:
rockchip_flexbus_set_fb1(rkfb, NULL, NULL);
return ret;
}
static int rockchip_flexbus_adc_remove(struct platform_device *pdev)
{
struct iio_dev *indio_dev = platform_get_drvdata(pdev);
struct rockchip_flexbus_adc *rkfb_adc = iio_priv(indio_dev);
struct rockchip_flexbus *rkfb = rkfb_adc->rkfb;
mutex_destroy(&rkfb_adc->lock);
if (rkfb_adc->ref_clk)
clk_disable_unprepare(rkfb_adc->ref_clk);
rockchip_flexbus_set_fb1(rkfb, NULL, NULL);
return 0;
}
static struct platform_driver rockchip_flexbus_adc_driver = {
.probe = rockchip_flexbus_adc_probe,
.remove = rockchip_flexbus_adc_remove,
.driver = {
.name = "rockchip_flexbus_adc",
.of_match_table = rockchip_flexbus_adc_of_match,
},
};
module_platform_driver(rockchip_flexbus_adc_driver);
MODULE_DESCRIPTION("Rockchip Flexbus ADC driver");
MODULE_LICENSE("GPL");