diff options
Diffstat (limited to 'drivers/iio/adc/xilinx-xadc-core.c')
| -rw-r--r-- | drivers/iio/adc/xilinx-xadc-core.c | 1354 |
1 files changed, 1354 insertions, 0 deletions
diff --git a/drivers/iio/adc/xilinx-xadc-core.c b/drivers/iio/adc/xilinx-xadc-core.c new file mode 100644 index 000000000..30b5a17ce --- /dev/null +++ b/drivers/iio/adc/xilinx-xadc-core.c @@ -0,0 +1,1354 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Xilinx XADC driver + * + * Copyright 2013-2014 Analog Devices Inc. + * Author: Lars-Peter Clausen <lars@metafoo.de> + * + * Documentation for the parts can be found at: + * - XADC hardmacro: Xilinx UG480 + * - ZYNQ XADC interface: Xilinx UG585 + * - AXI XADC interface: Xilinx PG019 + */ + +#include <linux/clk.h> +#include <linux/device.h> +#include <linux/err.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/overflow.h> +#include <linux/platform_device.h> +#include <linux/slab.h> +#include <linux/sysfs.h> + +#include <linux/iio/buffer.h> +#include <linux/iio/events.h> +#include <linux/iio/iio.h> +#include <linux/iio/sysfs.h> +#include <linux/iio/trigger.h> +#include <linux/iio/trigger_consumer.h> +#include <linux/iio/triggered_buffer.h> + +#include "xilinx-xadc.h" + +static const unsigned int XADC_ZYNQ_UNMASK_TIMEOUT = 500; + +/* ZYNQ register definitions */ +#define XADC_ZYNQ_REG_CFG 0x00 +#define XADC_ZYNQ_REG_INTSTS 0x04 +#define XADC_ZYNQ_REG_INTMSK 0x08 +#define XADC_ZYNQ_REG_STATUS 0x0c +#define XADC_ZYNQ_REG_CFIFO 0x10 +#define XADC_ZYNQ_REG_DFIFO 0x14 +#define XADC_ZYNQ_REG_CTL 0x18 + +#define XADC_ZYNQ_CFG_ENABLE BIT(31) +#define XADC_ZYNQ_CFG_CFIFOTH_MASK (0xf << 20) +#define XADC_ZYNQ_CFG_CFIFOTH_OFFSET 20 +#define XADC_ZYNQ_CFG_DFIFOTH_MASK (0xf << 16) +#define XADC_ZYNQ_CFG_DFIFOTH_OFFSET 16 +#define XADC_ZYNQ_CFG_WEDGE BIT(13) +#define XADC_ZYNQ_CFG_REDGE BIT(12) +#define XADC_ZYNQ_CFG_TCKRATE_MASK (0x3 << 8) +#define XADC_ZYNQ_CFG_TCKRATE_DIV2 (0x0 << 8) +#define XADC_ZYNQ_CFG_TCKRATE_DIV4 (0x1 << 8) +#define XADC_ZYNQ_CFG_TCKRATE_DIV8 (0x2 << 8) +#define XADC_ZYNQ_CFG_TCKRATE_DIV16 (0x3 << 8) +#define XADC_ZYNQ_CFG_IGAP_MASK 0x1f +#define XADC_ZYNQ_CFG_IGAP(x) (x) + +#define XADC_ZYNQ_INT_CFIFO_LTH BIT(9) +#define XADC_ZYNQ_INT_DFIFO_GTH BIT(8) +#define XADC_ZYNQ_INT_ALARM_MASK 0xff +#define XADC_ZYNQ_INT_ALARM_OFFSET 0 + +#define XADC_ZYNQ_STATUS_CFIFO_LVL_MASK (0xf << 16) +#define XADC_ZYNQ_STATUS_CFIFO_LVL_OFFSET 16 +#define XADC_ZYNQ_STATUS_DFIFO_LVL_MASK (0xf << 12) +#define XADC_ZYNQ_STATUS_DFIFO_LVL_OFFSET 12 +#define XADC_ZYNQ_STATUS_CFIFOF BIT(11) +#define XADC_ZYNQ_STATUS_CFIFOE BIT(10) +#define XADC_ZYNQ_STATUS_DFIFOF BIT(9) +#define XADC_ZYNQ_STATUS_DFIFOE BIT(8) +#define XADC_ZYNQ_STATUS_OT BIT(7) +#define XADC_ZYNQ_STATUS_ALM(x) BIT(x) + +#define XADC_ZYNQ_CTL_RESET BIT(4) + +#define XADC_ZYNQ_CMD_NOP 0x00 +#define XADC_ZYNQ_CMD_READ 0x01 +#define XADC_ZYNQ_CMD_WRITE 0x02 + +#define XADC_ZYNQ_CMD(cmd, addr, data) (((cmd) << 26) | ((addr) << 16) | (data)) + +/* AXI register definitions */ +#define XADC_AXI_REG_RESET 0x00 +#define XADC_AXI_REG_STATUS 0x04 +#define XADC_AXI_REG_ALARM_STATUS 0x08 +#define XADC_AXI_REG_CONVST 0x0c +#define XADC_AXI_REG_XADC_RESET 0x10 +#define XADC_AXI_REG_GIER 0x5c +#define XADC_AXI_REG_IPISR 0x60 +#define XADC_AXI_REG_IPIER 0x68 +#define XADC_AXI_ADC_REG_OFFSET 0x200 + +#define XADC_AXI_RESET_MAGIC 0xa +#define XADC_AXI_GIER_ENABLE BIT(31) + +#define XADC_AXI_INT_EOS BIT(4) +#define XADC_AXI_INT_ALARM_MASK 0x3c0f + +#define XADC_FLAGS_BUFFERED BIT(0) + +/* + * The XADC hardware supports a samplerate of up to 1MSPS. Unfortunately it does + * not have a hardware FIFO. Which means an interrupt is generated for each + * conversion sequence. At 1MSPS sample rate the CPU in ZYNQ7000 is completely + * overloaded by the interrupts that it soft-lockups. For this reason the driver + * limits the maximum samplerate 150kSPS. At this rate the CPU is fairly busy, + * but still responsive. + */ +#define XADC_MAX_SAMPLERATE 150000 + +static void xadc_write_reg(struct xadc *xadc, unsigned int reg, + uint32_t val) +{ + writel(val, xadc->base + reg); +} + +static void xadc_read_reg(struct xadc *xadc, unsigned int reg, + uint32_t *val) +{ + *val = readl(xadc->base + reg); +} + +/* + * The ZYNQ interface uses two asynchronous FIFOs for communication with the + * XADC. Reads and writes to the XADC register are performed by submitting a + * request to the command FIFO (CFIFO), once the request has been completed the + * result can be read from the data FIFO (DFIFO). The method currently used in + * this driver is to submit the request for a read/write operation, then go to + * sleep and wait for an interrupt that signals that a response is available in + * the data FIFO. + */ + +static void xadc_zynq_write_fifo(struct xadc *xadc, uint32_t *cmd, + unsigned int n) +{ + unsigned int i; + + for (i = 0; i < n; i++) + xadc_write_reg(xadc, XADC_ZYNQ_REG_CFIFO, cmd[i]); +} + +static void xadc_zynq_drain_fifo(struct xadc *xadc) +{ + uint32_t status, tmp; + + xadc_read_reg(xadc, XADC_ZYNQ_REG_STATUS, &status); + + while (!(status & XADC_ZYNQ_STATUS_DFIFOE)) { + xadc_read_reg(xadc, XADC_ZYNQ_REG_DFIFO, &tmp); + xadc_read_reg(xadc, XADC_ZYNQ_REG_STATUS, &status); + } +} + +static void xadc_zynq_update_intmsk(struct xadc *xadc, unsigned int mask, + unsigned int val) +{ + xadc->zynq_intmask &= ~mask; + xadc->zynq_intmask |= val; + + xadc_write_reg(xadc, XADC_ZYNQ_REG_INTMSK, + xadc->zynq_intmask | xadc->zynq_masked_alarm); +} + +static int xadc_zynq_write_adc_reg(struct xadc *xadc, unsigned int reg, + uint16_t val) +{ + uint32_t cmd[1]; + uint32_t tmp; + int ret; + + spin_lock_irq(&xadc->lock); + xadc_zynq_update_intmsk(xadc, XADC_ZYNQ_INT_DFIFO_GTH, + XADC_ZYNQ_INT_DFIFO_GTH); + + reinit_completion(&xadc->completion); + + cmd[0] = XADC_ZYNQ_CMD(XADC_ZYNQ_CMD_WRITE, reg, val); + xadc_zynq_write_fifo(xadc, cmd, ARRAY_SIZE(cmd)); + xadc_read_reg(xadc, XADC_ZYNQ_REG_CFG, &tmp); + tmp &= ~XADC_ZYNQ_CFG_DFIFOTH_MASK; + tmp |= 0 << XADC_ZYNQ_CFG_DFIFOTH_OFFSET; + xadc_write_reg(xadc, XADC_ZYNQ_REG_CFG, tmp); + + xadc_zynq_update_intmsk(xadc, XADC_ZYNQ_INT_DFIFO_GTH, 0); + spin_unlock_irq(&xadc->lock); + + ret = wait_for_completion_interruptible_timeout(&xadc->completion, HZ); + if (ret == 0) + ret = -EIO; + else + ret = 0; + + xadc_read_reg(xadc, XADC_ZYNQ_REG_DFIFO, &tmp); + + return ret; +} + +static int xadc_zynq_read_adc_reg(struct xadc *xadc, unsigned int reg, + uint16_t *val) +{ + uint32_t cmd[2]; + uint32_t resp, tmp; + int ret; + + cmd[0] = XADC_ZYNQ_CMD(XADC_ZYNQ_CMD_READ, reg, 0); + cmd[1] = XADC_ZYNQ_CMD(XADC_ZYNQ_CMD_NOP, 0, 0); + + spin_lock_irq(&xadc->lock); + xadc_zynq_update_intmsk(xadc, XADC_ZYNQ_INT_DFIFO_GTH, + XADC_ZYNQ_INT_DFIFO_GTH); + xadc_zynq_drain_fifo(xadc); + reinit_completion(&xadc->completion); + + xadc_zynq_write_fifo(xadc, cmd, ARRAY_SIZE(cmd)); + xadc_read_reg(xadc, XADC_ZYNQ_REG_CFG, &tmp); + tmp &= ~XADC_ZYNQ_CFG_DFIFOTH_MASK; + tmp |= 1 << XADC_ZYNQ_CFG_DFIFOTH_OFFSET; + xadc_write_reg(xadc, XADC_ZYNQ_REG_CFG, tmp); + + xadc_zynq_update_intmsk(xadc, XADC_ZYNQ_INT_DFIFO_GTH, 0); + spin_unlock_irq(&xadc->lock); + ret = wait_for_completion_interruptible_timeout(&xadc->completion, HZ); + if (ret == 0) + ret = -EIO; + if (ret < 0) + return ret; + + xadc_read_reg(xadc, XADC_ZYNQ_REG_DFIFO, &resp); + xadc_read_reg(xadc, XADC_ZYNQ_REG_DFIFO, &resp); + + *val = resp & 0xffff; + + return 0; +} + +static unsigned int xadc_zynq_transform_alarm(unsigned int alarm) +{ + return ((alarm & 0x80) >> 4) | + ((alarm & 0x78) << 1) | + (alarm & 0x07); +} + +/* + * The ZYNQ threshold interrupts are level sensitive. Since we can't make the + * threshold condition go way from within the interrupt handler, this means as + * soon as a threshold condition is present we would enter the interrupt handler + * again and again. To work around this we mask all active thresholds interrupts + * in the interrupt handler and start a timer. In this timer we poll the + * interrupt status and only if the interrupt is inactive we unmask it again. + */ +static void xadc_zynq_unmask_worker(struct work_struct *work) +{ + struct xadc *xadc = container_of(work, struct xadc, zynq_unmask_work.work); + unsigned int misc_sts, unmask; + + xadc_read_reg(xadc, XADC_ZYNQ_REG_STATUS, &misc_sts); + + misc_sts &= XADC_ZYNQ_INT_ALARM_MASK; + + spin_lock_irq(&xadc->lock); + + /* Clear those bits which are not active anymore */ + unmask = (xadc->zynq_masked_alarm ^ misc_sts) & xadc->zynq_masked_alarm; + xadc->zynq_masked_alarm &= misc_sts; + + /* Also clear those which are masked out anyway */ + xadc->zynq_masked_alarm &= ~xadc->zynq_intmask; + + /* Clear the interrupts before we unmask them */ + xadc_write_reg(xadc, XADC_ZYNQ_REG_INTSTS, unmask); + + xadc_zynq_update_intmsk(xadc, 0, 0); + + spin_unlock_irq(&xadc->lock); + + /* if still pending some alarm re-trigger the timer */ + if (xadc->zynq_masked_alarm) { + schedule_delayed_work(&xadc->zynq_unmask_work, + msecs_to_jiffies(XADC_ZYNQ_UNMASK_TIMEOUT)); + } + +} + +static irqreturn_t xadc_zynq_interrupt_handler(int irq, void *devid) +{ + struct iio_dev *indio_dev = devid; + struct xadc *xadc = iio_priv(indio_dev); + uint32_t status; + + xadc_read_reg(xadc, XADC_ZYNQ_REG_INTSTS, &status); + + status &= ~(xadc->zynq_intmask | xadc->zynq_masked_alarm); + + if (!status) + return IRQ_NONE; + + spin_lock(&xadc->lock); + + xadc_write_reg(xadc, XADC_ZYNQ_REG_INTSTS, status); + + if (status & XADC_ZYNQ_INT_DFIFO_GTH) { + xadc_zynq_update_intmsk(xadc, XADC_ZYNQ_INT_DFIFO_GTH, + XADC_ZYNQ_INT_DFIFO_GTH); + complete(&xadc->completion); + } + + status &= XADC_ZYNQ_INT_ALARM_MASK; + if (status) { + xadc->zynq_masked_alarm |= status; + /* + * mask the current event interrupt, + * unmask it when the interrupt is no more active. + */ + xadc_zynq_update_intmsk(xadc, 0, 0); + + xadc_handle_events(indio_dev, + xadc_zynq_transform_alarm(status)); + + /* unmask the required interrupts in timer. */ + schedule_delayed_work(&xadc->zynq_unmask_work, + msecs_to_jiffies(XADC_ZYNQ_UNMASK_TIMEOUT)); + } + spin_unlock(&xadc->lock); + + return IRQ_HANDLED; +} + +#define XADC_ZYNQ_TCK_RATE_MAX 50000000 +#define XADC_ZYNQ_IGAP_DEFAULT 20 +#define XADC_ZYNQ_PCAP_RATE_MAX 200000000 + +static int xadc_zynq_setup(struct platform_device *pdev, + struct iio_dev *indio_dev, int irq) +{ + struct xadc *xadc = iio_priv(indio_dev); + unsigned long pcap_rate; + unsigned int tck_div; + unsigned int div; + unsigned int igap; + unsigned int tck_rate; + int ret; + + /* TODO: Figure out how to make igap and tck_rate configurable */ + igap = XADC_ZYNQ_IGAP_DEFAULT; + tck_rate = XADC_ZYNQ_TCK_RATE_MAX; + + xadc->zynq_intmask = ~0; + + pcap_rate = clk_get_rate(xadc->clk); + if (!pcap_rate) + return -EINVAL; + + if (pcap_rate > XADC_ZYNQ_PCAP_RATE_MAX) { + ret = clk_set_rate(xadc->clk, + (unsigned long)XADC_ZYNQ_PCAP_RATE_MAX); + if (ret) + return ret; + } + + if (tck_rate > pcap_rate / 2) { + div = 2; + } else { + div = pcap_rate / tck_rate; + if (pcap_rate / div > XADC_ZYNQ_TCK_RATE_MAX) + div++; + } + + if (div <= 3) + tck_div = XADC_ZYNQ_CFG_TCKRATE_DIV2; + else if (div <= 7) + tck_div = XADC_ZYNQ_CFG_TCKRATE_DIV4; + else if (div <= 15) + tck_div = XADC_ZYNQ_CFG_TCKRATE_DIV8; + else + tck_div = XADC_ZYNQ_CFG_TCKRATE_DIV16; + + xadc_write_reg(xadc, XADC_ZYNQ_REG_CTL, XADC_ZYNQ_CTL_RESET); + xadc_write_reg(xadc, XADC_ZYNQ_REG_CTL, 0); + xadc_write_reg(xadc, XADC_ZYNQ_REG_INTSTS, ~0); + xadc_write_reg(xadc, XADC_ZYNQ_REG_INTMSK, xadc->zynq_intmask); + xadc_write_reg(xadc, XADC_ZYNQ_REG_CFG, XADC_ZYNQ_CFG_ENABLE | + XADC_ZYNQ_CFG_REDGE | XADC_ZYNQ_CFG_WEDGE | + tck_div | XADC_ZYNQ_CFG_IGAP(igap)); + + if (pcap_rate > XADC_ZYNQ_PCAP_RATE_MAX) { + ret = clk_set_rate(xadc->clk, pcap_rate); + if (ret) + return ret; + } + + return 0; +} + +static unsigned long xadc_zynq_get_dclk_rate(struct xadc *xadc) +{ + unsigned int div; + uint32_t val; + + xadc_read_reg(xadc, XADC_ZYNQ_REG_CFG, &val); + + switch (val & XADC_ZYNQ_CFG_TCKRATE_MASK) { + case XADC_ZYNQ_CFG_TCKRATE_DIV4: + div = 4; + break; + case XADC_ZYNQ_CFG_TCKRATE_DIV8: + div = 8; + break; + case XADC_ZYNQ_CFG_TCKRATE_DIV16: + div = 16; + break; + default: + div = 2; + break; + } + + return clk_get_rate(xadc->clk) / div; +} + +static void xadc_zynq_update_alarm(struct xadc *xadc, unsigned int alarm) +{ + unsigned long flags; + uint32_t status; + + /* Move OT to bit 7 */ + alarm = ((alarm & 0x08) << 4) | ((alarm & 0xf0) >> 1) | (alarm & 0x07); + + spin_lock_irqsave(&xadc->lock, flags); + + /* Clear previous interrupts if any. */ + xadc_read_reg(xadc, XADC_ZYNQ_REG_INTSTS, &status); + xadc_write_reg(xadc, XADC_ZYNQ_REG_INTSTS, status & alarm); + + xadc_zynq_update_intmsk(xadc, XADC_ZYNQ_INT_ALARM_MASK, + ~alarm & XADC_ZYNQ_INT_ALARM_MASK); + + spin_unlock_irqrestore(&xadc->lock, flags); +} + +static const struct xadc_ops xadc_zynq_ops = { + .read = xadc_zynq_read_adc_reg, + .write = xadc_zynq_write_adc_reg, + .setup = xadc_zynq_setup, + .get_dclk_rate = xadc_zynq_get_dclk_rate, + .interrupt_handler = xadc_zynq_interrupt_handler, + .update_alarm = xadc_zynq_update_alarm, +}; + +static int xadc_axi_read_adc_reg(struct xadc *xadc, unsigned int reg, + uint16_t *val) +{ + uint32_t val32; + + xadc_read_reg(xadc, XADC_AXI_ADC_REG_OFFSET + reg * 4, &val32); + *val = val32 & 0xffff; + + return 0; +} + +static int xadc_axi_write_adc_reg(struct xadc *xadc, unsigned int reg, + uint16_t val) +{ + xadc_write_reg(xadc, XADC_AXI_ADC_REG_OFFSET + reg * 4, val); + + return 0; +} + +static int xadc_axi_setup(struct platform_device *pdev, + struct iio_dev *indio_dev, int irq) +{ + struct xadc *xadc = iio_priv(indio_dev); + + xadc_write_reg(xadc, XADC_AXI_REG_RESET, XADC_AXI_RESET_MAGIC); + xadc_write_reg(xadc, XADC_AXI_REG_GIER, XADC_AXI_GIER_ENABLE); + + return 0; +} + +static irqreturn_t xadc_axi_interrupt_handler(int irq, void *devid) +{ + struct iio_dev *indio_dev = devid; + struct xadc *xadc = iio_priv(indio_dev); + uint32_t status, mask; + unsigned int events; + + xadc_read_reg(xadc, XADC_AXI_REG_IPISR, &status); + xadc_read_reg(xadc, XADC_AXI_REG_IPIER, &mask); + status &= mask; + + if (!status) + return IRQ_NONE; + + if ((status & XADC_AXI_INT_EOS) && xadc->trigger) + iio_trigger_poll(xadc->trigger); + + if (status & XADC_AXI_INT_ALARM_MASK) { + /* + * The order of the bits in the AXI-XADC status register does + * not match the order of the bits in the XADC alarm enable + * register. xadc_handle_events() expects the events to be in + * the same order as the XADC alarm enable register. + */ + events = (status & 0x000e) >> 1; + events |= (status & 0x0001) << 3; + events |= (status & 0x3c00) >> 6; + xadc_handle_events(indio_dev, events); + } + + xadc_write_reg(xadc, XADC_AXI_REG_IPISR, status); + + return IRQ_HANDLED; +} + +static void xadc_axi_update_alarm(struct xadc *xadc, unsigned int alarm) +{ + uint32_t val; + unsigned long flags; + + /* + * The order of the bits in the AXI-XADC status register does not match + * the order of the bits in the XADC alarm enable register. We get + * passed the alarm mask in the same order as in the XADC alarm enable + * register. + */ + alarm = ((alarm & 0x07) << 1) | ((alarm & 0x08) >> 3) | + ((alarm & 0xf0) << 6); + + spin_lock_irqsave(&xadc->lock, flags); + xadc_read_reg(xadc, XADC_AXI_REG_IPIER, &val); + val &= ~XADC_AXI_INT_ALARM_MASK; + val |= alarm; + xadc_write_reg(xadc, XADC_AXI_REG_IPIER, val); + spin_unlock_irqrestore(&xadc->lock, flags); +} + +static unsigned long xadc_axi_get_dclk(struct xadc *xadc) +{ + return clk_get_rate(xadc->clk); +} + +static const struct xadc_ops xadc_axi_ops = { + .read = xadc_axi_read_adc_reg, + .write = xadc_axi_write_adc_reg, + .setup = xadc_axi_setup, + .get_dclk_rate = xadc_axi_get_dclk, + .update_alarm = xadc_axi_update_alarm, + .interrupt_handler = xadc_axi_interrupt_handler, + .flags = XADC_FLAGS_BUFFERED, +}; + +static int _xadc_update_adc_reg(struct xadc *xadc, unsigned int reg, + uint16_t mask, uint16_t val) +{ + uint16_t tmp; + int ret; + + ret = _xadc_read_adc_reg(xadc, reg, &tmp); + if (ret) + return ret; + + return _xadc_write_adc_reg(xadc, reg, (tmp & ~mask) | val); +} + +static int xadc_update_adc_reg(struct xadc *xadc, unsigned int reg, + uint16_t mask, uint16_t val) +{ + int ret; + + mutex_lock(&xadc->mutex); + ret = _xadc_update_adc_reg(xadc, reg, mask, val); + mutex_unlock(&xadc->mutex); + + return ret; +} + +static unsigned long xadc_get_dclk_rate(struct xadc *xadc) +{ + return xadc->ops->get_dclk_rate(xadc); +} + +static int xadc_update_scan_mode(struct iio_dev *indio_dev, + const unsigned long *mask) +{ + struct xadc *xadc = iio_priv(indio_dev); + size_t new_size, n; + void *data; + + n = bitmap_weight(mask, indio_dev->masklength); + + if (check_mul_overflow(n, sizeof(*xadc->data), &new_size)) + return -ENOMEM; + + data = devm_krealloc(indio_dev->dev.parent, xadc->data, + new_size, GFP_KERNEL); + if (!data) + return -ENOMEM; + + memset(data, 0, new_size); + xadc->data = data; + + return 0; +} + +static unsigned int xadc_scan_index_to_channel(unsigned int scan_index) +{ + switch (scan_index) { + case 5: + return XADC_REG_VCCPINT; + case 6: + return XADC_REG_VCCPAUX; + case 7: + return XADC_REG_VCCO_DDR; + case 8: + return XADC_REG_TEMP; + case 9: + return XADC_REG_VCCINT; + case 10: + return XADC_REG_VCCAUX; + case 11: + return XADC_REG_VPVN; + case 12: + return XADC_REG_VREFP; + case 13: + return XADC_REG_VREFN; + case 14: + return XADC_REG_VCCBRAM; + default: + return XADC_REG_VAUX(scan_index - 16); + } +} + +static irqreturn_t xadc_trigger_handler(int irq, void *p) +{ + struct iio_poll_func *pf = p; + struct iio_dev *indio_dev = pf->indio_dev; + struct xadc *xadc = iio_priv(indio_dev); + unsigned int chan; + int i, j; + + if (!xadc->data) + goto out; + + j = 0; + for_each_set_bit(i, indio_dev->active_scan_mask, + indio_dev->masklength) { + chan = xadc_scan_index_to_channel(i); + xadc_read_adc_reg(xadc, chan, &xadc->data[j]); + j++; + } + + iio_push_to_buffers(indio_dev, xadc->data); + +out: + iio_trigger_notify_done(indio_dev->trig); + + return IRQ_HANDLED; +} + +static int xadc_trigger_set_state(struct iio_trigger *trigger, bool state) +{ + struct xadc *xadc = iio_trigger_get_drvdata(trigger); + unsigned long flags; + unsigned int convst; + unsigned int val; + int ret = 0; + + mutex_lock(&xadc->mutex); + + if (state) { + /* Only one of the two triggers can be active at a time. */ + if (xadc->trigger != NULL) { + ret = -EBUSY; + goto err_out; + } else { + xadc->trigger = trigger; + if (trigger == xadc->convst_trigger) + convst = XADC_CONF0_EC; + else + convst = 0; + } + ret = _xadc_update_adc_reg(xadc, XADC_REG_CONF1, XADC_CONF0_EC, + convst); + if (ret) + goto err_out; + } else { + xadc->trigger = NULL; + } + + spin_lock_irqsave(&xadc->lock, flags); + xadc_read_reg(xadc, XADC_AXI_REG_IPIER, &val); + xadc_write_reg(xadc, XADC_AXI_REG_IPISR, XADC_AXI_INT_EOS); + if (state) + val |= XADC_AXI_INT_EOS; + else + val &= ~XADC_AXI_INT_EOS; + xadc_write_reg(xadc, XADC_AXI_REG_IPIER, val); + spin_unlock_irqrestore(&xadc->lock, flags); + +err_out: + mutex_unlock(&xadc->mutex); + + return ret; +} + +static const struct iio_trigger_ops xadc_trigger_ops = { + .set_trigger_state = &xadc_trigger_set_state, +}; + +static struct iio_trigger *xadc_alloc_trigger(struct iio_dev *indio_dev, + const char *name) +{ + struct device *dev = indio_dev->dev.parent; + struct iio_trigger *trig; + int ret; + + trig = devm_iio_trigger_alloc(dev, "%s%d-%s", indio_dev->name, + indio_dev->id, name); + if (trig == NULL) + return ERR_PTR(-ENOMEM); + + trig->dev.parent = indio_dev->dev.parent; + trig->ops = &xadc_trigger_ops; + iio_trigger_set_drvdata(trig, iio_priv(indio_dev)); + + ret = devm_iio_trigger_register(dev, trig); + if (ret) + return ERR_PTR(ret); + + return trig; +} + +static int xadc_power_adc_b(struct xadc *xadc, unsigned int seq_mode) +{ + uint16_t val; + + /* Powerdown the ADC-B when it is not needed. */ + switch (seq_mode) { + case XADC_CONF1_SEQ_SIMULTANEOUS: + case XADC_CONF1_SEQ_INDEPENDENT: + val = 0; + break; + default: + val = XADC_CONF2_PD_ADC_B; + break; + } + + return xadc_update_adc_reg(xadc, XADC_REG_CONF2, XADC_CONF2_PD_MASK, + val); +} + +static int xadc_get_seq_mode(struct xadc *xadc, unsigned long scan_mode) +{ + unsigned int aux_scan_mode = scan_mode >> 16; + + if (xadc->external_mux_mode == XADC_EXTERNAL_MUX_DUAL) + return XADC_CONF1_SEQ_SIMULTANEOUS; + + if ((aux_scan_mode & 0xff00) == 0 || + (aux_scan_mode & 0x00ff) == 0) + return XADC_CONF1_SEQ_CONTINUOUS; + + return XADC_CONF1_SEQ_SIMULTANEOUS; +} + +static int xadc_postdisable(struct iio_dev *indio_dev) +{ + struct xadc *xadc = iio_priv(indio_dev); + unsigned long scan_mask; + int ret; + int i; + + scan_mask = 1; /* Run calibration as part of the sequence */ + for (i = 0; i < indio_dev->num_channels; i++) + scan_mask |= BIT(indio_dev->channels[i].scan_index); + + /* Enable all channels and calibration */ + ret = xadc_write_adc_reg(xadc, XADC_REG_SEQ(0), scan_mask & 0xffff); + if (ret) + return ret; + + ret = xadc_write_adc_reg(xadc, XADC_REG_SEQ(1), scan_mask >> 16); + if (ret) + return ret; + + ret = xadc_update_adc_reg(xadc, XADC_REG_CONF1, XADC_CONF1_SEQ_MASK, + XADC_CONF1_SEQ_CONTINUOUS); + if (ret) + return ret; + + return xadc_power_adc_b(xadc, XADC_CONF1_SEQ_CONTINUOUS); +} + +static int xadc_preenable(struct iio_dev *indio_dev) +{ + struct xadc *xadc = iio_priv(indio_dev); + unsigned long scan_mask; + int seq_mode; + int ret; + + ret = xadc_update_adc_reg(xadc, XADC_REG_CONF1, XADC_CONF1_SEQ_MASK, + XADC_CONF1_SEQ_DEFAULT); + if (ret) + goto err; + + scan_mask = *indio_dev->active_scan_mask; + seq_mode = xadc_get_seq_mode(xadc, scan_mask); + + ret = xadc_write_adc_reg(xadc, XADC_REG_SEQ(0), scan_mask & 0xffff); + if (ret) + goto err; + + /* + * In simultaneous mode the upper and lower aux channels are samples at + * the same time. In this mode the upper 8 bits in the sequencer + * register are don't care and the lower 8 bits control two channels + * each. As such we must set the bit if either the channel in the lower + * group or the upper group is enabled. + */ + if (seq_mode == XADC_CONF1_SEQ_SIMULTANEOUS) + scan_mask = ((scan_mask >> 8) | scan_mask) & 0xff0000; + + ret = xadc_write_adc_reg(xadc, XADC_REG_SEQ(1), scan_mask >> 16); + if (ret) + goto err; + + ret = xadc_power_adc_b(xadc, seq_mode); + if (ret) + goto err; + + ret = xadc_update_adc_reg(xadc, XADC_REG_CONF1, XADC_CONF1_SEQ_MASK, + seq_mode); + if (ret) + goto err; + + return 0; +err: + xadc_postdisable(indio_dev); + return ret; +} + +static const struct iio_buffer_setup_ops xadc_buffer_ops = { + .preenable = &xadc_preenable, + .postdisable = &xadc_postdisable, +}; + +static int xadc_read_samplerate(struct xadc *xadc) +{ + unsigned int div; + uint16_t val16; + int ret; + + ret = xadc_read_adc_reg(xadc, XADC_REG_CONF2, &val16); + if (ret) + return ret; + + div = (val16 & XADC_CONF2_DIV_MASK) >> XADC_CONF2_DIV_OFFSET; + if (div < 2) + div = 2; + + return xadc_get_dclk_rate(xadc) / div / 26; +} + +static int xadc_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, int *val, int *val2, long info) +{ + struct xadc *xadc = iio_priv(indio_dev); + uint16_t val16; + int ret; + + switch (info) { + case IIO_CHAN_INFO_RAW: + if (iio_buffer_enabled(indio_dev)) + return -EBUSY; + ret = xadc_read_adc_reg(xadc, chan->address, &val16); + if (ret < 0) + return ret; + + val16 >>= 4; + if (chan->scan_type.sign == 'u') + *val = val16; + else + *val = sign_extend32(val16, 11); + + return IIO_VAL_INT; + case IIO_CHAN_INFO_SCALE: + switch (chan->type) { + case IIO_VOLTAGE: + /* V = (val * 3.0) / 4096 */ + switch (chan->address) { + case XADC_REG_VCCINT: + case XADC_REG_VCCAUX: + case XADC_REG_VREFP: + case XADC_REG_VREFN: + case XADC_REG_VCCBRAM: + case XADC_REG_VCCPINT: + case XADC_REG_VCCPAUX: + case XADC_REG_VCCO_DDR: + *val = 3000; + break; + default: + *val = 1000; + break; + } + *val2 = 12; + return IIO_VAL_FRACTIONAL_LOG2; + case IIO_TEMP: + /* Temp in C = (val * 503.975) / 4096 - 273.15 */ + *val = 503975; + *val2 = 12; + return IIO_VAL_FRACTIONAL_LOG2; + default: + return -EINVAL; + } + case IIO_CHAN_INFO_OFFSET: + /* Only the temperature channel has an offset */ + *val = -((273150 << 12) / 503975); + return IIO_VAL_INT; + case IIO_CHAN_INFO_SAMP_FREQ: + ret = xadc_read_samplerate(xadc); + if (ret < 0) + return ret; + + *val = ret; + return IIO_VAL_INT; + default: + return -EINVAL; + } +} + +static int xadc_write_samplerate(struct xadc *xadc, int val) +{ + unsigned long clk_rate = xadc_get_dclk_rate(xadc); + unsigned int div; + + if (!clk_rate) + return -EINVAL; + + if (val <= 0) + return -EINVAL; + + /* Max. 150 kSPS */ + if (val > XADC_MAX_SAMPLERATE) + val = XADC_MAX_SAMPLERATE; + + val *= 26; + + /* Min 1MHz */ + if (val < 1000000) + val = 1000000; + + /* + * We want to round down, but only if we do not exceed the 150 kSPS + * limit. + */ + div = clk_rate / val; + if (clk_rate / div / 26 > XADC_MAX_SAMPLERATE) + div++; + if (div < 2) + div = 2; + else if (div > 0xff) + div = 0xff; + + return xadc_update_adc_reg(xadc, XADC_REG_CONF2, XADC_CONF2_DIV_MASK, + div << XADC_CONF2_DIV_OFFSET); +} + +static int xadc_write_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, int val, int val2, long info) +{ + struct xadc *xadc = iio_priv(indio_dev); + + if (info != IIO_CHAN_INFO_SAMP_FREQ) + return -EINVAL; + + return xadc_write_samplerate(xadc, val); +} + +static const struct iio_event_spec xadc_temp_events[] = { + { + .type = IIO_EV_TYPE_THRESH, + .dir = IIO_EV_DIR_RISING, + .mask_separate = BIT(IIO_EV_INFO_ENABLE) | + BIT(IIO_EV_INFO_VALUE) | + BIT(IIO_EV_INFO_HYSTERESIS), + }, +}; + +/* Separate values for upper and lower thresholds, but only a shared enabled */ +static const struct iio_event_spec xadc_voltage_events[] = { + { + .type = IIO_EV_TYPE_THRESH, + .dir = IIO_EV_DIR_RISING, + .mask_separate = BIT(IIO_EV_INFO_VALUE), + }, { + .type = IIO_EV_TYPE_THRESH, + .dir = IIO_EV_DIR_FALLING, + .mask_separate = BIT(IIO_EV_INFO_VALUE), + }, { + .type = IIO_EV_TYPE_THRESH, + .dir = IIO_EV_DIR_EITHER, + .mask_separate = BIT(IIO_EV_INFO_ENABLE), + }, +}; + +#define XADC_CHAN_TEMP(_chan, _scan_index, _addr) { \ + .type = IIO_TEMP, \ + .indexed = 1, \ + .channel = (_chan), \ + .address = (_addr), \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ + BIT(IIO_CHAN_INFO_SCALE) | \ + BIT(IIO_CHAN_INFO_OFFSET), \ + .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), \ + .event_spec = xadc_temp_events, \ + .num_event_specs = ARRAY_SIZE(xadc_temp_events), \ + .scan_index = (_scan_index), \ + .scan_type = { \ + .sign = 'u', \ + .realbits = 12, \ + .storagebits = 16, \ + .shift = 4, \ + .endianness = IIO_CPU, \ + }, \ +} + +#define XADC_CHAN_VOLTAGE(_chan, _scan_index, _addr, _ext, _alarm) { \ + .type = IIO_VOLTAGE, \ + .indexed = 1, \ + .channel = (_chan), \ + .address = (_addr), \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ + BIT(IIO_CHAN_INFO_SCALE), \ + .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), \ + .event_spec = (_alarm) ? xadc_voltage_events : NULL, \ + .num_event_specs = (_alarm) ? ARRAY_SIZE(xadc_voltage_events) : 0, \ + .scan_index = (_scan_index), \ + .scan_type = { \ + .sign = ((_addr) == XADC_REG_VREFN) ? 's' : 'u', \ + .realbits = 12, \ + .storagebits = 16, \ + .shift = 4, \ + .endianness = IIO_CPU, \ + }, \ + .extend_name = _ext, \ +} + +static const struct iio_chan_spec xadc_channels[] = { + XADC_CHAN_TEMP(0, 8, XADC_REG_TEMP), + XADC_CHAN_VOLTAGE(0, 9, XADC_REG_VCCINT, "vccint", true), + XADC_CHAN_VOLTAGE(1, 10, XADC_REG_VCCAUX, "vccaux", true), + XADC_CHAN_VOLTAGE(2, 14, XADC_REG_VCCBRAM, "vccbram", true), + XADC_CHAN_VOLTAGE(3, 5, XADC_REG_VCCPINT, "vccpint", true), + XADC_CHAN_VOLTAGE(4, 6, XADC_REG_VCCPAUX, "vccpaux", true), + XADC_CHAN_VOLTAGE(5, 7, XADC_REG_VCCO_DDR, "vccoddr", true), + XADC_CHAN_VOLTAGE(6, 12, XADC_REG_VREFP, "vrefp", false), + XADC_CHAN_VOLTAGE(7, 13, XADC_REG_VREFN, "vrefn", false), + XADC_CHAN_VOLTAGE(8, 11, XADC_REG_VPVN, NULL, false), + XADC_CHAN_VOLTAGE(9, 16, XADC_REG_VAUX(0), NULL, false), + XADC_CHAN_VOLTAGE(10, 17, XADC_REG_VAUX(1), NULL, false), + XADC_CHAN_VOLTAGE(11, 18, XADC_REG_VAUX(2), NULL, false), + XADC_CHAN_VOLTAGE(12, 19, XADC_REG_VAUX(3), NULL, false), + XADC_CHAN_VOLTAGE(13, 20, XADC_REG_VAUX(4), NULL, false), + XADC_CHAN_VOLTAGE(14, 21, XADC_REG_VAUX(5), NULL, false), + XADC_CHAN_VOLTAGE(15, 22, XADC_REG_VAUX(6), NULL, false), + XADC_CHAN_VOLTAGE(16, 23, XADC_REG_VAUX(7), NULL, false), + XADC_CHAN_VOLTAGE(17, 24, XADC_REG_VAUX(8), NULL, false), + XADC_CHAN_VOLTAGE(18, 25, XADC_REG_VAUX(9), NULL, false), + XADC_CHAN_VOLTAGE(19, 26, XADC_REG_VAUX(10), NULL, false), + XADC_CHAN_VOLTAGE(20, 27, XADC_REG_VAUX(11), NULL, false), + XADC_CHAN_VOLTAGE(21, 28, XADC_REG_VAUX(12), NULL, false), + XADC_CHAN_VOLTAGE(22, 29, XADC_REG_VAUX(13), NULL, false), + XADC_CHAN_VOLTAGE(23, 30, XADC_REG_VAUX(14), NULL, false), + XADC_CHAN_VOLTAGE(24, 31, XADC_REG_VAUX(15), NULL, false), +}; + +static const struct iio_info xadc_info = { + .read_raw = &xadc_read_raw, + .write_raw = &xadc_write_raw, + .read_event_config = &xadc_read_event_config, + .write_event_config = &xadc_write_event_config, + .read_event_value = &xadc_read_event_value, + .write_event_value = &xadc_write_event_value, + .update_scan_mode = &xadc_update_scan_mode, +}; + +static const struct of_device_id xadc_of_match_table[] = { + { .compatible = "xlnx,zynq-xadc-1.00.a", (void *)&xadc_zynq_ops }, + { .compatible = "xlnx,axi-xadc-1.00.a", (void *)&xadc_axi_ops }, + { }, +}; +MODULE_DEVICE_TABLE(of, xadc_of_match_table); + +static int xadc_parse_dt(struct iio_dev *indio_dev, struct device_node *np, + unsigned int *conf) +{ + struct device *dev = indio_dev->dev.parent; + struct xadc *xadc = iio_priv(indio_dev); + struct iio_chan_spec *channels, *chan; + struct device_node *chan_node, *child; + unsigned int num_channels; + const char *external_mux; + u32 ext_mux_chan; + u32 reg; + int ret; + + *conf = 0; + + ret = of_property_read_string(np, "xlnx,external-mux", &external_mux); + if (ret < 0 || strcasecmp(external_mux, "none") == 0) + xadc->external_mux_mode = XADC_EXTERNAL_MUX_NONE; + else if (strcasecmp(external_mux, "single") == 0) + xadc->external_mux_mode = XADC_EXTERNAL_MUX_SINGLE; + else if (strcasecmp(external_mux, "dual") == 0) + xadc->external_mux_mode = XADC_EXTERNAL_MUX_DUAL; + else + return -EINVAL; + + if (xadc->external_mux_mode != XADC_EXTERNAL_MUX_NONE) { + ret = of_property_read_u32(np, "xlnx,external-mux-channel", + &ext_mux_chan); + if (ret < 0) + return ret; + + if (xadc->external_mux_mode == XADC_EXTERNAL_MUX_SINGLE) { + if (ext_mux_chan == 0) + ext_mux_chan = XADC_REG_VPVN; + else if (ext_mux_chan <= 16) + ext_mux_chan = XADC_REG_VAUX(ext_mux_chan - 1); + else + return -EINVAL; + } else { + if (ext_mux_chan > 0 && ext_mux_chan <= 8) + ext_mux_chan = XADC_REG_VAUX(ext_mux_chan - 1); + else + return -EINVAL; + } + + *conf |= XADC_CONF0_MUX | XADC_CONF0_CHAN(ext_mux_chan); + } + + channels = devm_kmemdup(dev, xadc_channels, + sizeof(xadc_channels), GFP_KERNEL); + if (!channels) + return -ENOMEM; + + num_channels = 9; + chan = &channels[9]; + + chan_node = of_get_child_by_name(np, "xlnx,channels"); + if (chan_node) { + for_each_child_of_node(chan_node, child) { + if (num_channels >= ARRAY_SIZE(xadc_channels)) { + of_node_put(child); + break; + } + + ret = of_property_read_u32(child, "reg", ®); + if (ret || reg > 16) + continue; + + if (of_property_read_bool(child, "xlnx,bipolar")) + chan->scan_type.sign = 's'; + + if (reg == 0) { + chan->scan_index = 11; + chan->address = XADC_REG_VPVN; + } else { + chan->scan_index = 15 + reg; + chan->address = XADC_REG_VAUX(reg - 1); + } + num_channels++; + chan++; + } + } + of_node_put(chan_node); + + indio_dev->num_channels = num_channels; + indio_dev->channels = devm_krealloc(dev, channels, + sizeof(*channels) * num_channels, + GFP_KERNEL); + /* If we can't resize the channels array, just use the original */ + if (!indio_dev->channels) + indio_dev->channels = channels; + + return 0; +} + +static void xadc_clk_disable_unprepare(void *data) +{ + struct clk *clk = data; + + clk_disable_unprepare(clk); +} + +static void xadc_cancel_delayed_work(void *data) +{ + struct delayed_work *work = data; + + cancel_delayed_work_sync(work); +} + +static int xadc_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + const struct of_device_id *id; + struct iio_dev *indio_dev; + unsigned int bipolar_mask; + unsigned int conf0; + struct xadc *xadc; + int ret; + int irq; + int i; + + if (!dev->of_node) + return -ENODEV; + + id = of_match_node(xadc_of_match_table, dev->of_node); + if (!id) + return -EINVAL; + + irq = platform_get_irq(pdev, 0); + if (irq <= 0) + return -ENXIO; + + indio_dev = devm_iio_device_alloc(dev, sizeof(*xadc)); + if (!indio_dev) + return -ENOMEM; + + xadc = iio_priv(indio_dev); + xadc->ops = id->data; + xadc->irq = irq; + init_completion(&xadc->completion); + mutex_init(&xadc->mutex); + spin_lock_init(&xadc->lock); + INIT_DELAYED_WORK(&xadc->zynq_unmask_work, xadc_zynq_unmask_worker); + + xadc->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(xadc->base)) + return PTR_ERR(xadc->base); + + indio_dev->name = "xadc"; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->info = &xadc_info; + + ret = xadc_parse_dt(indio_dev, dev->of_node, &conf0); + if (ret) + return ret; + + if (xadc->ops->flags & XADC_FLAGS_BUFFERED) { + ret = devm_iio_triggered_buffer_setup(dev, indio_dev, + &iio_pollfunc_store_time, + &xadc_trigger_handler, + &xadc_buffer_ops); + if (ret) + return ret; + + xadc->convst_trigger = xadc_alloc_trigger(indio_dev, "convst"); + if (IS_ERR(xadc->convst_trigger)) + return PTR_ERR(xadc->convst_trigger); + + xadc->samplerate_trigger = xadc_alloc_trigger(indio_dev, + "samplerate"); + if (IS_ERR(xadc->samplerate_trigger)) + return PTR_ERR(xadc->samplerate_trigger); + } + + xadc->clk = devm_clk_get(dev, NULL); + if (IS_ERR(xadc->clk)) + return PTR_ERR(xadc->clk); + + ret = clk_prepare_enable(xadc->clk); + if (ret) + return ret; + + ret = devm_add_action_or_reset(dev, + xadc_clk_disable_unprepare, xadc->clk); + if (ret) + return ret; + + /* + * Make sure not to exceed the maximum samplerate since otherwise the + * resulting interrupt storm will soft-lock the system. + */ + if (xadc->ops->flags & XADC_FLAGS_BUFFERED) { + ret = xadc_read_samplerate(xadc); + if (ret < 0) + return ret; + + if (ret > XADC_MAX_SAMPLERATE) { + ret = xadc_write_samplerate(xadc, XADC_MAX_SAMPLERATE); + if (ret < 0) + return ret; + } + } + + ret = devm_request_irq(dev, xadc->irq, xadc->ops->interrupt_handler, 0, + dev_name(dev), indio_dev); + if (ret) + return ret; + + ret = devm_add_action_or_reset(dev, xadc_cancel_delayed_work, + &xadc->zynq_unmask_work); + if (ret) + return ret; + + ret = xadc->ops->setup(pdev, indio_dev, xadc->irq); + if (ret) + return ret; + + for (i = 0; i < 16; i++) + xadc_read_adc_reg(xadc, XADC_REG_THRESHOLD(i), + &xadc->threshold[i]); + + ret = xadc_write_adc_reg(xadc, XADC_REG_CONF0, conf0); + if (ret) + return ret; + + bipolar_mask = 0; + for (i = 0; i < indio_dev->num_channels; i++) { + if (indio_dev->channels[i].scan_type.sign == 's') + bipolar_mask |= BIT(indio_dev->channels[i].scan_index); + } + + ret = xadc_write_adc_reg(xadc, XADC_REG_INPUT_MODE(0), bipolar_mask); + if (ret) + return ret; + + ret = xadc_write_adc_reg(xadc, XADC_REG_INPUT_MODE(1), + bipolar_mask >> 16); + if (ret) + return ret; + + /* Go to non-buffered mode */ + xadc_postdisable(indio_dev); + + return devm_iio_device_register(dev, indio_dev); +} + +static struct platform_driver xadc_driver = { + .probe = xadc_probe, + .driver = { + .name = "xadc", + .of_match_table = xadc_of_match_table, + }, +}; +module_platform_driver(xadc_driver); + +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>"); +MODULE_DESCRIPTION("Xilinx XADC IIO driver"); |