On 04/02/14 17:24, Lars-Peter Clausen wrote:
The Xilinx XADC is a ADC that can be found in the series 7 FPGAs from Xilinx. The XADC has a DRP interface for communication. Currently two different frontends for the DRP interface exist. One that is only available on the ZYNQ family as a hardmacro in the SoC portion of the ZYNQ. The other one is available on all series 7 platforms and is a softmacro with a AXI interface. This driver supports both interfaces and internally has a small abstraction layer that hides the specifics of these interfaces from the main driver logic. The ADC has a couple of internal channels which are used for voltage and temperature monitoring of the FPGA as well as one primary and up to 16 channels auxiliary channels for measuring external voltages. The external auxiliary channels can either be directly connected each to one physical pin on the FPGA or they can make use of an external multiplexer which is responsible for multiplexing the external signals onto one pair of physical pins. The voltage and temperature monitoring channels also have an event capability which allows to generate a interrupt when their value falls below or raises above a set threshold. Buffered sampling mode is supported by the driver, but only for AXI-XADC since the ZYNQ XADC interface does not have capabilities for supporting buffer mode (no end-of-conversion interrupt). Signed-off-by: Lars-Peter Clausen <lars@xxxxxxxxxx>
Hi Lars, One double free bug in the error handling at the end of probe and a few requests for some explanatory comments. Otherwise looks great to me. Could you describe the two triggers in the description section of the patch. Also, if you could insert a few references to the relevant docs from Xilinx that would also be great! Hmm.. To think I read this one first as it looked like it might be the easiest driver in my inbox to review :) J
--- drivers/iio/adc/Kconfig | 13 + drivers/iio/adc/Makefile | 2 + drivers/iio/adc/xilinx-xadc-core.c | 1295 ++++++++++++++++++++++++++++++++++ drivers/iio/adc/xilinx-xadc-events.c | 265 +++++++ drivers/iio/adc/xilinx-xadc.h | 205 ++++++ 5 files changed, 1780 insertions(+) create mode 100644 drivers/iio/adc/xilinx-xadc-core.c create mode 100644 drivers/iio/adc/xilinx-xadc-events.c create mode 100644 drivers/iio/adc/xilinx-xadc.h diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig index 2209f28..75bd07a 100644 --- a/drivers/iio/adc/Kconfig +++ b/drivers/iio/adc/Kconfig @@ -204,4 +204,17 @@ config VIPERBOARD_ADC Say yes here to access the ADC part of the Nano River Technologies Viperboard. +config XILINX_XADC + tristate "Xilinx XADC driver" + depends on ARCH_ZYNQ || MICROBLAZE || COMPILE_TEST + depends on HAS_IOMEM + select IIO_BUFFER + select IIO_TRIGGERED_BUFFER + help + Say yes here to have support for the Xilinx XADC. The driver does support + both the ZYNQ interface to the XADC as well as the AXI-XADC interface. + + The driver can also be build as a module. If so, the module will be called + xilinx-xadc. + endmenu diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile index ba9a10a..885ea70 100644 --- a/drivers/iio/adc/Makefile +++ b/drivers/iio/adc/Makefile @@ -22,3 +22,5 @@ obj-$(CONFIG_TI_ADC081C) += ti-adc081c.o obj-$(CONFIG_TI_AM335X_ADC) += ti_am335x_adc.o obj-$(CONFIG_TWL6030_GPADC) += twl6030-gpadc.o obj-$(CONFIG_VIPERBOARD_ADC) += viperboard_adc.o +xilinx-xadc-y := xilinx-xadc-core.o xilinx-xadc-events.o +obj-$(CONFIG_XILINX_XADC) += xilinx-xadc.o diff --git a/drivers/iio/adc/xilinx-xadc-core.c b/drivers/iio/adc/xilinx-xadc-core.c new file mode 100644 index 0000000..ebc9463 --- /dev/null +++ b/drivers/iio/adc/xilinx-xadc-core.c @@ -0,0 +1,1295 @@ +/* + * Xilinx XADC driver + * + * Copyright 2013-2014 Analog Devices Inc. + * Author: Lars-Peter Clauen <lars@xxxxxxxxxx> + * + * Licensed under the GPL-2. + */ + +#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/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) + +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); +} + +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); +} +
Hmm. These are complex beasts. I'm not entirely sure I've understood them correctly... Might take another look at some point.
+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_threaded_interrupt_handler(int irq, void *devid) +{ + struct iio_dev *indio_dev = devid; + struct xadc *xadc = iio_priv(indio_dev); + unsigned int alarm; + + spin_lock_irq(&xadc->lock); + alarm = xadc->zynq_alarm; + xadc->zynq_alarm = 0; + spin_unlock_irq(&xadc->lock); + + xadc_handle_events(indio_dev, xadc_zynq_transform_alarm(alarm)); + + /* unmask the required interrupts in timer. */ + schedule_delayed_work(&xadc->zynq_unmask_work, + msecs_to_jiffies(XADC_ZYNQ_UNMASK_TIMEOUT)); + + return IRQ_HANDLED; +} + +static irqreturn_t xadc_zynq_interrupt_handler(int irq, void *devid) +{ + struct iio_dev *indio_dev = devid; + struct xadc *xadc = iio_priv(indio_dev); + irqreturn_t ret = IRQ_HANDLED; + 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_alarm |= 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); + ret = IRQ_WAKE_THREAD; + } + spin_unlock(&xadc->lock); + + return ret; +} + +#define XADC_ZYNQ_TCK_RATE_MAX 50000000 +#define XADC_ZYNQ_IGAP_DEFAULT 20 + +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; + + /* 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 (tck_rate > XADC_ZYNQ_TCK_RATE_MAX) + tck_rate = XADC_ZYNQ_TCK_RATE_MAX; + 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)); + + 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, + .threaded_interrupt_handler = xadc_zynq_threaded_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, 0); + + if (status & XADC_AXI_INT_ALARM_MASK) { + 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; + + 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; + + mutex_lock(&xadc->mutex); + + ret = _xadc_read_adc_reg(xadc, reg, &tmp); + if (ret) + goto err_unlock; + + ret = _xadc_write_adc_reg(xadc, reg, (tmp & ~mask) | val); +err_unlock: + 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); + unsigned int n; + + n = bitmap_weight(mask, indio_dev->masklength); + + kfree(xadc->data); + xadc->data = kcalloc(n, sizeof(*xadc->data), GFP_KERNEL); + if (!xadc->data) + return -ENOMEM; + + 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 the 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, val & 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 = { + .owner = THIS_MODULE, + .set_trigger_state = &xadc_trigger_set_state, +}; + +static struct iio_trigger *xadc_alloc_trigger(struct iio_dev *indio_dev, + const char *name) +{ + struct iio_trigger *trig; + int ret; + + trig = iio_trigger_alloc("%s-%s%d", indio_dev->name, name, + indio_dev->id); + 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 = iio_trigger_register(trig); + if (ret) + goto error_free_trig; + + return trig; + +error_free_trig: + iio_trigger_free(trig); + return ERR_PTR(ret); +} + +static int xadc_power_adc_b(struct xadc *xadc, unsigned int seq_mode) +{ + uint16_t val; + + switch (seq_mode) { + case XADC_CONF1_SEQ_SIMULTANEOUS: + case XADC_CONF1_SEQ_INDEPENDENT: + val = XADC_CONF2_PD_ADC_B; + break; + default: + val = 0; + 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; + + 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 struct iio_buffer_setup_ops xadc_buffer_ops = { + .preenable = &xadc_preenable, + .postenable = &iio_triggered_buffer_postenable, + .predisable = &iio_triggered_buffer_predisable, + .postdisable = &xadc_postdisable, +}; + +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); + unsigned int div; + 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_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_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; + + *val = xadc_get_dclk_rate(xadc) / div / 26; + + return IIO_VAL_INT; + default: + return -EINVAL; + } +} + +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); + unsigned long clk_rate = xadc_get_dclk_rate(xadc); + unsigned int div; + + if (info != IIO_CHAN_INFO_SAMP_FREQ) + return -EINVAL; + + if (val <= 0) + return -EINVAL; + + /* Max. 150 kSPS */ + if (val > 150000) + val = 150000; + + 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 > 150000) + 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 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), + }, +}; + +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_ENABLE) | + BIT(IIO_EV_INFO_VALUE), + }, { + .type = IIO_EV_TYPE_THRESH, + .dir = IIO_EV_DIR_FALLING, + .mask_separate = BIT(IIO_EV_INFO_ENABLE) | + BIT(IIO_EV_INFO_VALUE), + }, +}; + +#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 = 'u', \ + .realbits = 12, \ + .storagebits = 16, \ + .shift = 4, \ + .endianness = IIO_CPU, \ + }, \ + .extend_name = _ext, \ +} +
I rather like your approach to customising the connected channels. It's quite clean and allows for a simple fixed set. Very nice.
+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_VCCINT, "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, "vcco_ddr", 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, + .driver_module = THIS_MODULE, +}; + +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 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; + int 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 = kmemdup(xadc_channels, sizeof(xadc_channels), GFP_KERNEL); + if (!channels) + return -ENOMEM; + + num_channels = 9; + chan = &channels[9]; + + chan_node = of_find_node_by_name(np, "xlnx,channels"); + if (chan_node) { + for_each_child_of_node(chan_node, child) { + if (num_channels >= ARRAY_SIZE(xadc_channels)) + 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->scan_index = XADC_REG_VAUX(reg - 1); + } + num_channels++; + chan++; + } + } + + indio_dev->num_channels = num_channels; + indio_dev->channels = krealloc(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 int xadc_probe(struct platform_device *pdev) +{ + const struct of_device_id *id; + struct iio_dev *indio_dev; + unsigned int bipolar_mask; + struct resource *mem; + unsigned int conf0; + struct xadc *xadc; + int ret; + int irq; + int i; + + if (!pdev->dev.of_node) + return -ENODEV; + + id = of_match_node(xadc_of_match_table, pdev->dev.of_node); + if (!id) + return -EINVAL; + + irq = platform_get_irq(pdev, 0); + if (irq <= 0) + return -ENXIO; + + indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*xadc)); + if (!indio_dev) + return -ENOMEM; + + xadc = iio_priv(indio_dev); + xadc->ops = id->data; + init_completion(&xadc->completion); + mutex_init(&xadc->mutex); + spin_lock_init(&xadc->lock); + INIT_DELAYED_WORK(&xadc->zynq_unmask_work, xadc_zynq_unmask_worker); + + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); + xadc->base = devm_ioremap_resource(&pdev->dev, mem); + if (IS_ERR(xadc->base)) + return PTR_ERR(xadc->base); + + indio_dev->dev.parent = &pdev->dev; + indio_dev->dev.of_node = pdev->dev.of_node; + indio_dev->name = "xadc"; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->info = &xadc_info; + + ret = xadc_parse_dt(indio_dev, pdev->dev.of_node, &conf0); + if (ret) + goto err_device_free; + + if (xadc->ops->flags & XADC_FLAGS_BUFFERED) { + ret = iio_triggered_buffer_setup(indio_dev, + &iio_pollfunc_store_time, &xadc_trigger_handler, + &xadc_buffer_ops); + if (ret) + goto err_device_free; + + xadc->convst_trigger = xadc_alloc_trigger(indio_dev, "convst"); + if (IS_ERR(xadc->convst_trigger)) + goto err_triggered_buffer_cleanup; + xadc->samplerate_trigger = xadc_alloc_trigger(indio_dev, + "samplerate"); + if (IS_ERR(xadc->samplerate_trigger)) + goto err_free_convst_trigger; + } + + xadc->clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(xadc->clk)) { + ret = PTR_ERR(xadc->clk); + goto err_free_samplerate_trigger; + } + clk_prepare_enable(xadc->clk); + + ret = xadc->ops->setup(pdev, indio_dev, irq); + if (ret) + goto err_free_samplerate_trigger; + + ret = request_threaded_irq(irq, xadc->ops->interrupt_handler, + xadc->ops->threaded_interrupt_handler, + 0, dev_name(&pdev->dev), indio_dev); + if (ret) + goto err_clk_disable_unprepare; + + 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) + goto err_free_irq; + + 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) + goto err_free_irq; + ret = xadc_write_adc_reg(xadc, XADC_REG_INPUT_MODE(1), + bipolar_mask >> 16); + if (ret) + goto err_free_irq; + + /* Disable all alarms */ + xadc_update_adc_reg(xadc, XADC_REG_CONF1, XADC_CONF1_ALARM_MASK, + XADC_CONF1_ALARM_MASK); + + /* Set thresholds to min/max */ + for (i = 0; i < 16; i++) { + /* + * Set max voltage threshold and both temperature thresholds to + * 0xffff, min voltage threshold to 0. + */ + if (i % 8 < 4 || i == 7) + xadc->threshold[i] = 0xffff; + else + xadc->threshold[i] = 0; + xadc_write_adc_reg(xadc, XADC_REG_THRESHOLD(i), + xadc->threshold[i]); + } + + /* Go to non-buffered mode */ + xadc_postdisable(indio_dev); + + ret = iio_device_register(indio_dev); + if (ret) + goto err_free_irq; + + platform_set_drvdata(pdev, indio_dev); + + return 0; + +err_free_irq: + free_irq(irq, indio_dev); +err_free_samplerate_trigger: + if (xadc->ops->flags & XADC_FLAGS_BUFFERED) + iio_trigger_free(xadc->samplerate_trigger); +err_free_convst_trigger: + if (xadc->ops->flags & XADC_FLAGS_BUFFERED) + iio_trigger_free(xadc->convst_trigger); +err_triggered_buffer_cleanup: + if (xadc->ops->flags & XADC_FLAGS_BUFFERED) + iio_triggered_buffer_cleanup(indio_dev); +err_clk_disable_unprepare: + clk_disable_unprepare(xadc->clk); +err_device_free: + kfree(indio_dev->channels); + iio_device_free(indio_dev);
Don't want the iio_device_free given you've use devm_iio_device_alloc
+ + return ret; +} + +static int xadc_remove(struct platform_device *pdev) +{ + struct iio_dev *indio_dev = platform_get_drvdata(pdev); + struct xadc *xadc = iio_priv(indio_dev); + int irq = platform_get_irq(pdev, 0); + + iio_device_unregister(indio_dev); + if (xadc->ops->flags & XADC_FLAGS_BUFFERED) { + iio_trigger_free(xadc->convst_trigger); + iio_trigger_free(xadc->samplerate_trigger);
It is trivial but your ordering here doesn't reverse that in probe. Please flip the two lines above.
+ iio_triggered_buffer_cleanup(indio_dev); + } + free_irq(irq, indio_dev); + clk_disable_unprepare(xadc->clk); + cancel_delayed_work(&xadc->zynq_unmask_work); + kfree(xadc->data); + kfree(indio_dev->channels); + + return 0; +} + +static struct platform_driver xadc_driver = { + .probe = xadc_probe, + .remove = xadc_remove, + .driver = { + .name = "xadc", + .owner = THIS_MODULE, + .of_match_table = xadc_of_match_table, + }, +}; +module_platform_driver(xadc_driver); + +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("Lars-Peter Clausen <lars@xxxxxxxxxx>"); +MODULE_DESCRIPTION("Xilinx XADC IIO driver"); diff --git a/drivers/iio/adc/xilinx-xadc-events.c b/drivers/iio/adc/xilinx-xadc-events.c new file mode 100644 index 0000000..e94035f --- /dev/null +++ b/drivers/iio/adc/xilinx-xadc-events.c @@ -0,0 +1,265 @@ +/* + * Xilinx XADC driver + * + * Copyright 2013 Analog Devices Inc. + * Author: Lars-Peter Clauen <lars@xxxxxxxxxx> + * + * Licensed under the GPL-2. + */ + +#include <linux/iio/events.h> +#include <linux/iio/iio.h> +#include <linux/kernel.h> + +#include "xilinx-xadc.h" + +static void xadc_handle_event(struct iio_dev *indio_dev, unsigned int event) +{ + struct xadc *xadc = iio_priv(indio_dev); + const struct iio_chan_spec *chan; + unsigned int offset; + uint16_t val; + int ret; + + /* Temperature threshold error, we don't handle this yet */ + if (event == 0) + return; + + if (event < 4) + offset = event; + else + offset = event + 4; + + if (event < 3) + chan = &indio_dev->channels[event]; + else if (event == 3) + chan = &indio_dev->channels[0]; + else + chan = &indio_dev->channels[event - 1]; + + if (event != 3) {
Is there any guarantee that, by the time we get here, the value will not have crossed back over the threshold? Might be better just to not separate the two and use IIO_EV_DIR_EITHER. I'm not sure either way on this one.
+ ret = xadc_read_adc_reg(xadc, chan->address, &val); + if (ret) + return; + + if ((xadc->threshold_state & BIT(offset)) && + val >= xadc->threshold[offset]) { + iio_push_event(indio_dev, + IIO_UNMOD_EVENT_CODE(chan->type, chan->channel, + IIO_EV_TYPE_THRESH, IIO_EV_DIR_RISING), + iio_get_time_ns()); + } + + if ((xadc->threshold_state & BIT(offset + 4)) + && val <= xadc->threshold[offset + 4]) { + iio_push_event(indio_dev, + IIO_UNMOD_EVENT_CODE(chan->type, chan->channel, + IIO_EV_TYPE_THRESH, IIO_EV_DIR_FALLING), + iio_get_time_ns()); + } + + } else { + iio_push_event(indio_dev, + IIO_UNMOD_EVENT_CODE(chan->type, chan->channel, + IIO_EV_TYPE_THRESH, IIO_EV_DIR_RISING), + iio_get_time_ns()); + } + +} + +void xadc_handle_events(struct iio_dev *indio_dev, unsigned long events) +{ + unsigned int i; + + for_each_set_bit(i, &events, 8) + xadc_handle_event(indio_dev, i); +} + +static unsigned int xadc_get_active_alarms(struct xadc *xadc) +{ + unsigned int alarm; + unsigned int state = xadc->threshold_state; +
Ouch this is confusing. Perhaps a comment to explain what is going on?
+ alarm = ((state & 0x00f0) >> 4) | (state & 0x000f); + alarm |= ((state & 0xf000) >> 8) | ((state & 0x0f00) >> 4); + + return alarm; +} + +static unsigned xadc_get_threshold_offset(const struct iio_chan_spec *chan, + enum iio_event_type type, enum iio_event_direction dir) +{ + unsigned int offset; + + if (chan->type == IIO_TEMP) { + offset = 3; + } else { + if (chan->channel < 2) + offset = chan->channel + 1; + else + offset = chan->channel + 6; + } + + if (dir == IIO_EV_DIR_FALLING) + offset += 4; + + return offset; +} + +static int xadc_write_event_threshold(struct xadc *xadc, + const struct iio_chan_spec *chan, unsigned int offset, + unsigned int val) +{ + int ret; + + if (offset == 3) { + /* + * According to the datasheet we need to set the lower 4 bits to + * 0x3, otherwise 125 degree celsius will be used as the + * threshold. + */ + val = (val & ~0xf) | 0x3; + } + + ret = _xadc_write_adc_reg(xadc, XADC_REG_THRESHOLD(offset), val); + if (ret) + return ret; + + if (chan->type == IIO_TEMP) { + ret = _xadc_write_adc_reg(xadc, XADC_REG_THRESHOLD(offset + 4), + xadc->threshold[offset + 4]); + } + return ret; +} + +int xadc_read_event_config(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan, enum iio_event_type type, + enum iio_event_direction dir) +{ + unsigned int offset = xadc_get_threshold_offset(chan, type, dir); + struct xadc *xadc = iio_priv(indio_dev); + + return (bool)(xadc->threshold_state & BIT(offset)); +} + +int xadc_write_event_config(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan, enum iio_event_type type, + enum iio_event_direction dir, int state) +{ + unsigned int offset = xadc_get_threshold_offset(chan, type, dir); + struct xadc *xadc = iio_priv(indio_dev); + unsigned int alarm; + uint16_t val, cfg, old_cfg; + int ret; + + mutex_lock(&xadc->mutex); + + if (!state) { + /* + * Unfortunately there is only one alarm interrupt signal per + * channel and it is triggered by both low and high threshold + * events. So if we enable
disable? Or you mean enable the other threshold?
a threshold set the limit to the + * min/max value to avoid accidentally triggering the threshold. + */ + if (dir == IIO_EV_DIR_FALLING) + val = 0; + else + val = 0xffff; + } else { + val = xadc->threshold[offset]; + } + + ret = xadc_write_event_threshold(xadc, chan, offset, val); + if (ret) + goto err_out; + + if (state) + xadc->threshold_state |= BIT(offset); + else + xadc->threshold_state &= ~BIT(offset); + + alarm = xadc_get_active_alarms(xadc); + + xadc->ops->update_alarm(xadc, alarm); + + ret = _xadc_read_adc_reg(xadc, XADC_REG_CONF1, &cfg); + if (ret) + goto err_out; + old_cfg = cfg; + cfg |= XADC_CONF1_ALARM_MASK; + cfg &= ~((alarm & 0xf0) << 4); /* bram, pint, paux, ddr */ + cfg &= ~((alarm & 0x08) >> 3); /* ot */ + cfg &= ~((alarm & 0x07) << 1); /* temp, vccint, vccaux */ + if (old_cfg != cfg) + ret = _xadc_write_adc_reg(xadc, XADC_REG_CONF1, cfg); + +err_out: + mutex_unlock(&xadc->mutex); + + return ret; +} + +int xadc_read_event_value(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan, enum iio_event_type type, + enum iio_event_direction dir, enum iio_event_info info, + int *val, int *val2) +{ + unsigned int offset = xadc_get_threshold_offset(chan, type, dir); + struct xadc *xadc = iio_priv(indio_dev); + + switch (info) { + case IIO_EV_INFO_VALUE: + *val = xadc->threshold[offset] >> 4; + break; + case IIO_EV_INFO_HYSTERESIS: + *val = xadc->temp_hysteresis >> 4; + break; + default: + return -EINVAL; + } + + return IIO_VAL_INT; +} + +int xadc_write_event_value(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan, enum iio_event_type type, + enum iio_event_direction dir, enum iio_event_info info, + int val, int val2) +{ + unsigned int offset = xadc_get_threshold_offset(chan, type, dir); + struct xadc *xadc = iio_priv(indio_dev); + int ret = 0; + + val <<= 4; + + if (val < 0 || val > 0xffff) + return -EINVAL; + + mutex_lock(&xadc->mutex); + + switch (info) { + case IIO_EV_INFO_VALUE: + xadc->threshold[offset] = val; + break; + case IIO_EV_INFO_HYSTERESIS: + xadc->temp_hysteresis = val; + break; + default: + return -EINVAL; + } +
This next bit could do with an explanatory comment. I think I know what is going on, but it's not obvious.
+ if (chan->type == IIO_TEMP) { + if (xadc->threshold[offset] < xadc->temp_hysteresis) { + xadc->threshold[offset + 4] = 0; + } else { + xadc->threshold[offset + 4] = xadc->threshold[offset] - + xadc->temp_hysteresis; + } + } + + if (xadc->threshold_state & BIT(offset)) + ret = xadc_write_event_threshold(xadc, chan, offset, val); + mutex_unlock(&xadc->mutex); + + return ret; +} diff --git a/drivers/iio/adc/xilinx-xadc.h b/drivers/iio/adc/xilinx-xadc.h new file mode 100644 index 0000000..a346fbb --- /dev/null +++ b/drivers/iio/adc/xilinx-xadc.h @@ -0,0 +1,205 @@ +/* + * Xilinx XADC driver + * + * Copyright 2013 Analog Devices Inc. + * Author: Lars-Peter Clauen <lars@xxxxxxxxxx> + * + * Licensed under the GPL-2. + */ + +#ifndef __IIO_XILINX_XADC__ +#define __IIO_XILINX_XADC__ + +#include <linux/interrupt.h> +#include <linux/mutex.h> +#include <linux/spinlock.h> + +struct iio_dev; +struct clk; +struct xadc_ops; +struct platform_device; + +void xadc_handle_events(struct iio_dev *indio_dev, unsigned long events); + +int xadc_read_event_config(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan, enum iio_event_type type, + enum iio_event_direction dir); +int xadc_write_event_config(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan, enum iio_event_type type, + enum iio_event_direction dir, int state); +int xadc_read_event_value(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan, enum iio_event_type type, + enum iio_event_direction dir, enum iio_event_info info, + int *val, int *val2); +int xadc_write_event_value(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan, enum iio_event_type type, + enum iio_event_direction dir, enum iio_event_info info, + int val, int val2); + +enum xadc_external_mux_mode { + XADC_EXTERNAL_MUX_NONE, + XADC_EXTERNAL_MUX_SINGLE, + XADC_EXTERNAL_MUX_DUAL, +}; + +struct xadc { + void __iomem *base; + struct clk *clk; + + const struct xadc_ops *ops; + + uint16_t threshold[16]; + unsigned int threshold_state; + unsigned int temp_hysteresis; + + uint16_t *data; + + struct iio_trigger *trigger; + struct iio_trigger *convst_trigger; + struct iio_trigger *samplerate_trigger; + + enum xadc_external_mux_mode external_mux_mode; + + unsigned int zynq_alarm; + unsigned int zynq_masked_alarm; + unsigned int zynq_intmask; + struct delayed_work zynq_unmask_work; + + struct mutex mutex; + spinlock_t lock; + + struct completion completion; +}; + +struct xadc_ops { + int (*read)(struct xadc *, unsigned int, uint16_t *); + int (*write)(struct xadc *, unsigned int, uint16_t); + int (*setup)(struct platform_device *pdev, struct iio_dev *indio_dev, + int irq); + void (*update_alarm)(struct xadc *, unsigned int); + unsigned long (*get_dclk_rate)(struct xadc *); + irqreturn_t (*interrupt_handler)(int, void *); + irqreturn_t (*threaded_interrupt_handler)(int, void *); + + unsigned int flags; +}; + +static inline int _xadc_read_adc_reg(struct xadc *xadc, unsigned int reg, + uint16_t *val) +{ + return xadc->ops->read(xadc, reg, val); +} + +static inline int _xadc_write_adc_reg(struct xadc *xadc, unsigned int reg, + uint16_t val) +{ + return xadc->ops->write(xadc, reg, val); +} + +static inline int xadc_read_adc_reg(struct xadc *xadc, unsigned int reg, + uint16_t *val) +{ + int ret; + mutex_lock(&xadc->mutex); + ret = _xadc_read_adc_reg(xadc, reg, val); + mutex_unlock(&xadc->mutex); + return ret; +} + +static inline int xadc_write_adc_reg(struct xadc *xadc, unsigned int reg, + uint16_t val) +{ + int ret; + mutex_lock(&xadc->mutex); + ret = _xadc_write_adc_reg(xadc, reg, val); + mutex_unlock(&xadc->mutex); + return ret; +} + +/* XADC hardmacro register definitions */ +#define XADC_REG_TEMP 0x00 +#define XADC_REG_VCCINT 0x01 +#define XADC_REG_VCCAUX 0x02 +#define XADC_REG_VPVN 0x03 +#define XADC_REG_VREFP 0x04 +#define XADC_REG_VREFN 0x05 +#define XADC_REG_VCCBRAM 0x06 + +#define XADC_REG_VCCPINT 0x0d +#define XADC_REG_VCCPAUX 0x0e +#define XADC_REG_VCCO_DDR 0x0f +#define XADC_REG_VAUX(x) (0x10 + (x)) + +#define XADC_REG_MAX_TEMP 0x20 +#define XADC_REG_MAX_VCCINT 0x21 +#define XADC_REG_MAX_VCCAUX 0x22 +#define XADC_REG_MAX_VCCBRAM 0x23 +#define XADC_REG_MIN_TEMP 0x24 +#define XADC_REG_MIN_VCCINT 0x25 +#define XADC_REG_MIN_VCCAUX 0x26 +#define XADC_REG_MIN_VCCBRAM 0x27 +#define XADC_REG_MAX_VCCPINT 0x28 +#define XADC_REG_MAX_VCCPAUX 0x29 +#define XADC_REG_MAX_VCCO_DDR 0x2a +#define XADC_REG_MIN_VCCPINT 0x2b +#define XADC_REG_MIN_VCCPAUX 0x2c +#define XADC_REG_MIN_VCCO_DDR 0x2d + +#define XADC_REG_CONF0 0x40 +#define XADC_REG_CONF1 0x41 +#define XADC_REG_CONF2 0x42 +#define XADC_REG_SEQ(x) (0x48 + (x)) +#define XADC_REG_INPUT_MODE(x) (0x4c + (x)) +#define XADC_REG_THRESHOLD(x) (0x50 + (x)) + +#define XADC_REG_FLAG 0x3f + +#define XADC_CONF0_EC BIT(9) +#define XADC_CONF0_ACQ BIT(8) +#define XADC_CONF0_MUX BIT(11) +#define XADC_CONF0_CHAN(x) (x) + +#define XADC_CONF1_SEQ_MASK (0xf << 12) +#define XADC_CONF1_SEQ_DEFAULT (0 << 12) +#define XADC_CONF1_SEQ_SINGLE_PASS (1 << 12) +#define XADC_CONF1_SEQ_CONTINUOUS (2 << 12) +#define XADC_CONF1_SEQ_SINGLE_CHANNEL (3 << 12) +#define XADC_CONF1_SEQ_SIMULTANEOUS (4 << 12) +#define XADC_CONF1_SEQ_INDEPENDENT (8 << 12) +#define XADC_CONF1_ALARM_MASK 0x0f0f + +#define XADC_CONF2_DIV_MASK 0xff00 +#define XADC_CONF2_DIV_OFFSET 8 + +#define XADC_CONF2_PD_MASK (0x3 << 4) +#define XADC_CONF2_PD_NONE (0x0 << 4) +#define XADC_CONF2_PD_ADC_B (0x2 << 4) +#define XADC_CONF2_PD_BOTH (0x3 << 4) + +#define XADC_ALARM_TEMP_MASK BIT(0) +#define XADC_ALARM_VCCINT_MASK BIT(1) +#define XADC_ALARM_VCCAUX_MASK BIT(2) +#define XADC_ALARM_OT_MASK BIT(3) +#define XADC_ALARM_VCCBRAM_MASK BIT(4) +#define XADC_ALARM_VCCPINT_MASK BIT(5) +#define XADC_ALARM_VCCPAUX_MASK BIT(6) +#define XADC_ALARM_VCCODDR_MASK BIT(7) + +#define XADC_THRESHOLD_TEMP_MAX 0x0 +#define XADC_THRESHOLD_VCCINT_MAX 0x1 +#define XADC_THRESHOLD_VCCAUX_MAX 0x2 +#define XADC_THRESHOLD_OT_MAX 0x3 +#define XADC_THRESHOLD_TEMP_MIN 0x4 +#define XADC_THRESHOLD_VCCINT_MIN 0x5 +#define XADC_THRESHOLD_VCCAUX_MIN 0x6 +#define XADC_THRESHOLD_OT_MIN 0x7 +#define XADC_THRESHOLD_VCCBRAM_MAX 0x8 +#define XADC_THRESHOLD_VCCPINT_MAX 0x9 +#define XADC_THRESHOLD_VCCPAUX_MAX 0xa +#define XADC_THRESHOLD_VCCODDR_MAX 0xb +#define XADC_THRESHOLD_VCCBRAM_MIN 0xc +#define XADC_THRESHOLD_VCCPINT_MIN 0xd +#define XADC_THRESHOLD_VCCPAUX_MIN 0xe +#define XADC_THRESHOLD_VCCODDR_MIN 0xf + +#endif
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