some clarification below
> >To: Duan Fugang-B38611
> >Cc: jic23@xxxxxxxxxx; shawn.guo@xxxxxxxxxx; linux-iio@xxxxxxxxxxxxxxx
> >Subject: Re: [PATCH v3 2/3] iio:adc:imx: add Freescale Vybrid vf610 adc driver
> >
> >On Tue, 26 Nov 2013, Fugang Duan wrote:
> >
> >> Add Freescale Vybrid vf610 adc driver. The driver only support ADC
> >> software trigger.
> >
> >nitpicking below
> >
> >> Signed-off-by: Fugang Duan <B38611@xxxxxxxxxxxxx>
> >> ---
> >> drivers/iio/adc/Kconfig | 11 +
> >> drivers/iio/adc/Makefile | 1 +
> >> drivers/iio/adc/vf610_adc.c | 744
> >> +++++++++++++++++++++++++++++++++++++++++++
> >> 3 files changed, 756 insertions(+), 0 deletions(-)
> >>
> >> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig index
> >> 2209f28..d0476ec 100644
> >> --- a/drivers/iio/adc/Kconfig
> >> +++ b/drivers/iio/adc/Kconfig
> >> @@ -204,4 +204,15 @@ config VIPERBOARD_ADC
> >> Say yes here to access the ADC part of the Nano River
> >> Technologies Viperboard.
> >>
> >> +config VF610_ADC
> >
> >alphabetic order please
>
> Got it. Thanks.
> >
> >> + tristate "Freescale vf610 ADC driver"
> >> + help
> >> + Say yes here if you want support for the Vybrid board
> >> + analog-to-digital converter.
> >> + Since the IP is used for i.MX6SLX and i.MX7 serial sillicons, the
> >driver
> >> + also support the subsequent chips.
> >> +
> >> + This driver can also be built as a module. If so, the module will be
> >> + called vf610_adc.
> >> +
> >> endmenu
> >> diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile index
> >> ba9a10a..c39ae38 100644
> >> --- a/drivers/iio/adc/Makefile
> >> +++ b/drivers/iio/adc/Makefile
> >> @@ -22,3 +22,4 @@ 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
> >> +obj-$(CONFIG_VF610_ADC) += vf610_adc.o
> >
> >keep alphabetic order
>
> Got it. Thanks.
> >
> >> diff --git a/drivers/iio/adc/vf610_adc.c b/drivers/iio/adc/vf610_adc.c
> >> new file mode 100644 index 0000000..0c200d91
> >> --- /dev/null
> >> +++ b/drivers/iio/adc/vf610_adc.c
> >> @@ -0,0 +1,744 @@
> >> +/*
> >> + * Freescale Vybrid vf610 ADC driver
> >> + *
> >> + * Copyright 2013 Freescale Semiconductor, Inc.
> >> + *
> >> + * This program is free software; you can redistribute it and/or
> >> +modify
> >> + * it under the terms of the GNU General Public License as published
> >> +by
> >> + * the Free Software Foundation; either version 2 of the License, or
> >> + * (at your option) any later version.
> >> + *
> >> + * This program is distributed in the hope that it will be useful,
> >> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> >> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> >> + * GNU General Public License for more details.
> >> + *
> >> + * You should have received a copy of the GNU General Public License
> >> + * along with this program; if not, write to the Free Software
> >> + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
> >> + */
> >> +
> >> +#include <linux/module.h>
> >> +#include <linux/platform_device.h>
> >> +#include <linux/interrupt.h>
> >> +#include <linux/delay.h>
> >> +#include <linux/kernel.h>
> >> +#include <linux/slab.h>
> >> +#include <linux/io.h>
> >> +#include <linux/clk.h>
> >> +#include <linux/completion.h>
> >> +#include <linux/of.h>
> >> +#include <linux/of_irq.h>
> >> +#include <linux/regulator/consumer.h> #include <linux/of_platform.h>
> >> +#include <linux/err.h>
> >> +
> >> +#include <linux/iio/iio.h>
> >> +#include <linux/iio/machine.h>
> >> +#include <linux/iio/driver.h>
> >> +
> >> +/* This will be the driver name the kernel reports */ #define
> >> +DRIVER_NAME "vf610-adc"
> >> +
> >> +/* Vybrid/IMX ADC registers */
> >
> >VF610_ prefix
>
> Hmm, I think it is not necessary to add prefix for the register address.
the argument for the prefix is that something in the headers you include
may #define ADC_SOMETHING in the future and cause breakage; prefixing
reduces this risk
plus other define have the prefix, so for the sake of consistency...
> >
> >> +#define ADC_HC0 0x00
> >> +#define ADC_HC1 0x04
> >> +#define ADC_HS 0x08
> >> +#define ADC_R0 0x0c
> >> +#define ADC_R1 0x10
> >> +#define ADC_CFG 0x14
> >> +#define ADC_GC 0x18
> >> +#define ADC_GS 0x1c
> >> +#define ADC_CV 0x20
> >> +#define ADC_OFS 0x24
> >> +#define ADC_CAL 0x28
> >> +#define ADC_PCTL 0x30
> >> +
> >> +/* Configuration register field define */
> >> +#define VF610_ADC_MODE_BIT8 0x00
> >> +#define VF610_ADC_MODE_BIT10 0x04
> >> +#define VF610_ADC_MODE_BIT12 0x08
> >> +#define VF610_ADC_DATA_BIT8_MASK 0xFF
> >> +#define VF610_ADC_DATA_BIT10_MASK 0x3FF
> >> +#define VF610_ADC_DATA_BIT12_MASK 0xFFF
> >> +#define VF610_ADC_BUSCLK2_SEL 0x01
> >> +#define VF610_ADC_ALTCLK_SEL 0x02
> >> +#define VF610_ADC_ADACK_SEL 0x03
> >> +#define VF610_ADC_CLK_DIV2 0x20
> >> +#define VF610_ADC_CLK_DIV4 0x40
> >> +#define VF610_ADC_CLK_DIV8 0x60
> >> +#define VF610_ADC_ADLSMP_LONG 0x10
> >> +#define VF610_ADC_ADSTS_SHORT 0x100
> >> +#define VF610_ADC_ADSTS_NORMAL 0x200
> >> +#define VF610_ADC_ADSTS_LONG 0x300
> >> +#define VF610_ADC_ADLPC_EN 0x80
> >> +#define VF610_ADC_ADHSC_EN 0x400
> >> +#define VF610_ADC_REFSEL_VALT 0x100
> >> +#define VF610_ADC_REFSEL_VBG 0x1000
> >> +#define VF610_ADC_ADTRG_HARD 0x2000
> >> +#define VF610_ADC_AVGS_8 0x4000
> >> +#define VF610_ADC_AVGS_16 0x8000
> >> +#define VF610_ADC_AVGS_32 0xC000
> >> +#define VF610_ADC_OVWREN 0x10000
> >> +
> >> +/* General control register field define */
> >> +#define VF610_ADC_ADACKEN 0x1
> >> +#define VF610_ADC_DMAEN 0x2
> >> +#define VF610_ADC_ACREN 0x4
> >> +#define VF610_ADC_ACFGT 0x8
> >> +#define VF610_ADC_ACFE 0x10
> >> +#define VF610_ADC_AVGEN 0x20
> >> +#define VF610_ADC_ADCON 0x40
> >> +#define VF610_ADC_CAL 0x80
> >> +
> >> +/* Other field define */
> >> +#define VF610_ADC_IOPCTL5 0x20
> >> +#define VF610_ADC_ADCHC(x) ((x) & 0xF)
> >> +#define VF610_ADC_AIEN (1 << 7)
> >> +#define VF610_ADC_CONV_DISABLE 0x1F
> >> +#define VF610_ADC_HS_COCO0 0x1
> >> +#define VF610_ADC_CALF 0x2
> >> +#define VF610_ADC_MAX_CHANS_NUM 16
> >> +#define VF610_ADC_TIMEOUT (msecs_to_jiffies(100))
> >
> >no parenthesis needed
>
> Got it, thanks!
> >
> >> +
> >> +enum clk_sel {
> >> + ADCIOC_BUSCLK_SET,
> >> + ADCIOC_ALTCLK_SET,
> >> + ADCIOC_ADACK_SET,
> >
> >VF610 prefix
>
> Got it, thanks!
> >
> >> +};
> >> +
> >> +enum vol_ref {
> >> + VF610_ADCIOC_VR_VREF_SET,
> >> + VF610_ADCIOC_VR_VALT_SET,
> >> + VF610_ADCIOC_VR_VBG_SET,
> >> +};
> >> +
> >> +struct vf610_adc_feature {
> >> + enum clk_sel clk_sel;
> >> + enum vol_ref vol_ref;
> >> +
> >> + int pctl;
> >> + int clk_div_num;
> >> + int res_mode;
> >> + int sam_time;
> >> + int hw_sam;
> >> +
> >> + bool calibration;
> >> + bool cc_en;
> >> + bool dataov_en;
> >> + bool hw_average;
> >> + bool tri_hw;
> >> + bool hs_oper;
> >> + bool lpm;
> >> + bool dma_en;
> >> + bool ac_clk_en;
> >> + bool cmp_func_en;
> >> + bool cmp_range_en;
> >> + bool cmp_greater_en;
> >> +};
> >> +
> >> +struct vf610_adc {
> >> + struct device *dev;
> >> + void __iomem *regs;
> >> + struct clk *clk;
> >> + unsigned int irq;
> >> +
> >> + u32 vref_uv;
> >> + u32 value;
> >> + struct regulator *vref;
> >> + struct vf610_adc_feature adc_feature;
> >> +
> >> + struct completion completion;
> >> +};
> >> +
> >> +#define VF610_ADC_CHAN(_idx, _chan_type) { \
> >> + .type = (_chan_type), \
> >> + .indexed = 1, \
> >> + .channel = _idx, \
> >> + .address = _idx, \
> >
> >address not needed
>
> Got it, thanks!
> >
> >> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
> >> + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
> >> +}
> >> +
> >> +static const struct iio_chan_spec vf610_adc_iio_channels[] = {
> >> + VF610_ADC_CHAN(0, IIO_VOLTAGE),
> >> + VF610_ADC_CHAN(1, IIO_VOLTAGE),
> >> + VF610_ADC_CHAN(2, IIO_VOLTAGE),
> >> + VF610_ADC_CHAN(3, IIO_VOLTAGE),
> >> + VF610_ADC_CHAN(4, IIO_VOLTAGE),
> >> + VF610_ADC_CHAN(5, IIO_VOLTAGE),
> >> + VF610_ADC_CHAN(6, IIO_VOLTAGE),
> >> + VF610_ADC_CHAN(7, IIO_VOLTAGE),
> >> + VF610_ADC_CHAN(8, IIO_VOLTAGE),
> >> + VF610_ADC_CHAN(9, IIO_VOLTAGE),
> >> + VF610_ADC_CHAN(10, IIO_VOLTAGE),
> >> + VF610_ADC_CHAN(11, IIO_VOLTAGE),
> >> + VF610_ADC_CHAN(12, IIO_VOLTAGE),
> >> + VF610_ADC_CHAN(13, IIO_VOLTAGE),
> >> + VF610_ADC_CHAN(14, IIO_VOLTAGE),
> >> + VF610_ADC_CHAN(15, IIO_VOLTAGE),
> >> +};
> >> +
> >> +static void vf610_adc_cfg_of_init(struct vf610_adc *info) {
> >> + struct device_node *np = info->dev->of_node;
> >> +
> >> + /*
> >> + * set default Configuration for ADC controller
> >> + * This config may upgrade to require from DT
> >
> >what does "This config may upgrade to require from DT" mean?
>
> There many configurations for ADC, and I have import some setting from DT, below some setting is static defined.
> In fact, all setting can get from DT.
>
> I don't want to static define the ADC setting, expect for getting them from DT, how to config them in runtime for user ?
> IIO subsystem don't have such interface for it. I think the only solution is to add ioctl interface for the driver. How do you think ?
I was just picking on the wording; I fail to understand what is meant by
the comment
> >> + */
> >> + info->adc_feature.clk_sel = ADCIOC_BUSCLK_SET;
> >> + info->adc_feature.vol_ref = VF610_ADCIOC_VR_VREF_SET;
> >> + info->adc_feature.calibration = true;
> >> + info->adc_feature.tri_hw = false;
> >> + info->adc_feature.dataov_en = true;
> >> + info->adc_feature.ac_clk_en = false;
> >> + info->adc_feature.dma_en = false;
> >> + info->adc_feature.cc_en = false;
> >> + info->adc_feature.cmp_func_en = false;
> >> + info->adc_feature.cmp_range_en = false;
> >> + info->adc_feature.cmp_greater_en = false;
> >> +
> >> + if (of_property_read_u32(np, "fsl,adc-io-pinctl",
> >> + &info->adc_feature.pctl)) {
> >> + info->adc_feature.pctl = VF610_ADC_IOPCTL5;
> >> + dev_info(info->dev,
> >> + "Miss adc-io-pinctl in dt, enable pin SE5.\n");
> >
> >"Missing" probably
> >
>
> Got it, thanks!
>
> >> + }
> >> +
> >> + if (info->vref)
> >> + info->vref_uv = regulator_get_voltage(info->vref);
> >> + else if (of_property_read_u32(np, "fsl,adc-vref", &info->vref_uv))
> >> + dev_err(info->dev,
> >> + "Miss adc-vref property or vref regulator in the DT.\n");
> >> +
> >> + if (of_property_read_u32(np, "fsl,adc-clk-div",
> >> + &info->adc_feature.clk_div_num)) {
> >> + info->adc_feature.clk_div_num = 2;
> >> + dev_info(info->dev,
> >> + "Miss adc-clk-div in dt, set divider to 2.\n");
> >> + }
> >> +
> >> + if (of_property_read_u32(np, "fsl,adc-res",
> >> + &info->adc_feature.res_mode)) {
> >> + info->adc_feature.res_mode = 12;
> >> + dev_info(info->dev,
> >> + "Miss adc-res property in dt, use 8bit mode.\n");
> >> + }
> >> +
> >> + if (of_property_read_u32(np, "fsl,adc-sam-time",
> >> + &info->adc_feature.sam_time)) {
> >> + info->adc_feature.sam_time = 4;
> >> + dev_info(info->dev,
> >> + "Miss adc-sam-time property in dt, set to 4.\n");
> >> + }
> >> +
> >> + info->adc_feature.hw_average = of_property_read_bool(np,
> >> + "fsl,adc-hw-aver-en");
> >> + if (info->adc_feature.hw_average &&
> >> + of_property_read_u32(np, "fsl,adc-aver-sam-sel",
> >> + &info->adc_feature.hw_sam)) {
> >> + info->adc_feature.hw_sam = 4;
> >> + dev_info(info->dev,
> >> + "Miss adc-aver-sam-sel property in dt, set to 4.\n");
> >> + }
> >> +
> >> + info->adc_feature.lpm = of_property_read_bool(np, "fsl,adc-low-power-
> >mode");
> >> + info->adc_feature.hs_oper = of_property_read_bool(np,
> >> +"fsl,adc-high-speed-conv"); }
> >> +
> >> +static inline void vf610_adc_cfg_post_set(struct vf610_adc *info) {
> >> + struct vf610_adc_feature *adc_feature = &(info->adc_feature);
> >
> >no parenthesis needed
>
> Got it , thanks!
> >
> >> + int cfg_data = 0;
> >> + int gc_data = 0;
> >> +
> >> + /* clock select and clock devider */
> >> + switch (adc_feature->clk_div_num) {
> >> + case 1:
> >> + break;
> >> + case 2:
> >> + cfg_data |= VF610_ADC_CLK_DIV2;
> >> + break;
> >> + case 4:
> >> + cfg_data |= VF610_ADC_CLK_DIV4;
> >> + break;
> >> + case 8:
> >> + cfg_data |= VF610_ADC_CLK_DIV8;
> >> + break;
> >> + case 16:
> >> + switch (adc_feature->clk_sel) {
> >> + case ADCIOC_BUSCLK_SET:
> >> + cfg_data |= VF610_ADC_BUSCLK2_SEL | VF610_ADC_CLK_DIV8;
> >> + break;
> >> + default:
> >> + dev_err(info->dev, "error clk divider\n");
> >
> >all those errors just logged and then ignored; shouldn't this be warnings then
> >or the handling improved?
>
> If the setting is error, use the default setting, and print out err log for user.
> In there, it use the default setting in fact.
> >
> >> + break;
> >> + }
> >> + break;
> >> + }
> >> +
> >> + switch (adc_feature->clk_sel) {
> >> + case ADCIOC_ALTCLK_SET:
> >> + cfg_data |= VF610_ADC_ALTCLK_SEL;
> >> + break;
> >> + case ADCIOC_ADACK_SET:
> >> + cfg_data |= VF610_ADC_ADACK_SEL;
> >> + break;
> >> + default:
> >> + break;
> >> + }
> >> +
> >> + /* resolution mode */
> >> + switch (adc_feature->res_mode) {
> >> + case 8:
> >> + cfg_data |= VF610_ADC_MODE_BIT8;
> >> + break;
> >> + case 10:
> >> + cfg_data |= VF610_ADC_MODE_BIT10;
> >> + break;
> >> + case 12:
> >> + cfg_data |= VF610_ADC_MODE_BIT12;
> >> + break;
> >> + default:
> >> + dev_err(info->dev, "error resolution mode\n");
> >> + break;
> >> + }
> >> +
> >> + /* Defines the sample time duration */
> >> + switch (adc_feature->sam_time) {
> >> + case 2:
> >> + break;
> >> + case 4:
> >> + cfg_data |= VF610_ADC_ADSTS_SHORT;
> >> + break;
> >> + case 6:
> >> + cfg_data |= VF610_ADC_ADSTS_NORMAL;
> >> + break;
> >> + case 8:
> >> + cfg_data |= VF610_ADC_ADSTS_LONG;
> >> + break;
> >> + case 12:
> >> + cfg_data |= VF610_ADC_ADLSMP_LONG;
> >> + break;
> >> + case 16:
> >> + cfg_data |= VF610_ADC_ADLSMP_LONG | VF610_ADC_ADSTS_SHORT;
> >> + break;
> >> + case 20:
> >> + cfg_data |= VF610_ADC_ADLSMP_LONG | VF610_ADC_ADSTS_NORMAL;
> >> + break;
> >> + case 24:
> >> + cfg_data |= VF610_ADC_ADLSMP_LONG | VF610_ADC_ADSTS_LONG;
> >> + break;
> >> + default:
> >> + dev_err(info->dev, "error sample duration\n");
> >> + break;
> >> + }
> >> +
> >> + /* low power configuration */
> >> + cfg_data |= VF610_ADC_ADLPC_EN;
> >> +
> >> + /* high speed operation */
> >> + cfg_data |= VF610_ADC_ADHSC_EN;
> >> +
> >> + /* voltage reference*/
> >
> >blank before */
>
> You are very careful, thanks!
>
> >
> >> + switch (adc_feature->vol_ref) {
> >> + case VF610_ADCIOC_VR_VREF_SET:
> >> + break;
> >> + case VF610_ADCIOC_VR_VALT_SET:
> >> + cfg_data |= VF610_ADC_REFSEL_VALT;
> >> + break;
> >> + case VF610_ADCIOC_VR_VBG_SET:
> >> + cfg_data |= VF610_ADC_REFSEL_VBG;
> >> + break;
> >> + default:
> >> + dev_err(info->dev, "error voltage reference\n");
> >> + }
> >> +
> >> + /* trigger select */
> >> + if (adc_feature->tri_hw)
> >> + cfg_data |= VF610_ADC_ADTRG_HARD;
> >> +
> >> + /* hardware average select */
> >> + if (adc_feature->hw_average) {
> >> + switch (adc_feature->hw_sam) {
> >> + case 4:
> >> + break;
> >> + case 8:
> >> + cfg_data |= VF610_ADC_AVGS_8;
> >> + break;
> >> + case 16:
> >> + cfg_data |= VF610_ADC_AVGS_16;
> >> + break;
> >> + case 32:
> >> + cfg_data |= VF610_ADC_AVGS_32;
> >> + break;
> >> + default:
> >> + dev_err(info->dev,
> >> + "error hardware sample average select\n");
> >> + }
> >> +
> >> + gc_data |= VF610_ADC_AVGEN;
> >> + }
> >> +
> >> + /* data overwrite enable */
> >> + if (adc_feature->dataov_en)
> >> + cfg_data |= VF610_ADC_OVWREN;
> >> +
> >> + /* Asynchronous clock output enable */
> >> + if (adc_feature->ac_clk_en)
> >> + gc_data |= VF610_ADC_ADACKEN;
> >> +
> >> + /* dma enable */
> >> + if (adc_feature->dma_en)
> >> + gc_data |= VF610_ADC_DMAEN;
> >> +
> >> + /* continue function enable */
> >> + if (adc_feature->cc_en)
> >> + gc_data |= VF610_ADC_ADCON;
> >> +
> >> + /* compare function enable */
> >> + if (adc_feature->cmp_func_en)
> >> + gc_data |= VF610_ADC_ACFE;
> >> +
> >> + /* greater than enable */
> >> + if (adc_feature->cmp_greater_en)
> >> + gc_data |= VF610_ADC_ACFGT;
> >> +
> >> + /* range enable */
> >> + if (adc_feature->cmp_range_en)
> >> + gc_data |= VF610_ADC_ACREN;
> >> +
> >> + writel(cfg_data, info->regs + ADC_CFG);
> >> + writel(gc_data, info->regs + ADC_GC); }
> >> +
> >> +static void vf610_adc_calibration(struct vf610_adc *info) {
> >> + int adc_gc, hc_cfg;
> >> + int timeout;
> >> +
> >> + if (!info->adc_feature.calibration)
> >> + return;
> >> +
> >> + /* enable calibration interrupt */
> >> + hc_cfg = VF610_ADC_AIEN | VF610_ADC_CONV_DISABLE;
> >> + writel(hc_cfg, info->regs + ADC_HC0);
> >> +
> >> + adc_gc = readl(info->regs + ADC_GC);
> >> + writel(adc_gc | VF610_ADC_CAL, info->regs + ADC_GC);
> >> +
> >> + timeout = wait_for_completion_interruptible_timeout
> >> + (&info->completion, VF610_ADC_TIMEOUT);
> >> + if (timeout == 0)
> >> + dev_err(info->dev, "Timeout for adc calibration\n");
> >
> >error ignored
> >
> Got it, thanks!
> There cannot be interrupted for calibration.
> So use wait_for_completion_timeout() instead of wait_for_completion_interruptible_timeout().
>
> >> +
> >> + adc_gc = readl(info->regs + ADC_GS);
> >> + if (adc_gc & VF610_ADC_CALF)
> >> + dev_err(info->dev, "ADC calibration failed\n");
> >> +
> >> + info->adc_feature.calibration = false; }
> >> +
> >> +static inline void vf610_adc_cfg_set(struct vf610_adc *info) {
> >
> >why are some functions marked inline and others not?
> >this function does not seem time critical
>
> Agree, I will remove the inline.
> >
> >> + struct vf610_adc_feature *adc_feature = &(info->adc_feature);
> >> + int cfg_data = 0;
> >> +
> >> + cfg_data = readl(info->regs + ADC_CFG);
> >> +
> >> + /* low power configuration */
> >> + if (!adc_feature->lpm)
> >> + cfg_data &= ~VF610_ADC_ADLPC_EN;
> >> +
> >> + /* high speed operation */
> >> + if (!adc_feature->hs_oper)
> >> + cfg_data &= ~VF610_ADC_ADHSC_EN;
> >> +
> >> + /* trigger select */
> >> + if (adc_feature->tri_hw)
> >> + cfg_data |= VF610_ADC_ADTRG_HARD;
> >> +
> >> + writel(cfg_data, info->regs + ADC_CFG); }
> >> +
> >> +static void vf610_adc_hw_init(struct vf610_adc *info) {
> >> + /* pin control for Sliding rheostat */
> >> + writel(info->adc_feature.pctl, info->regs + ADC_PCTL);
> >> +
> >> + /* CFG: Feature set */
> >> + vf610_adc_cfg_post_set(info);
> >> +
> >> + /* adc calibration */
> >> + vf610_adc_calibration(info);
> >> +
> >> + /* CFG: power and speed set */
> >> + vf610_adc_cfg_set(info);
> >> +}
> >> +
> >> +static inline int vf610_adc_read_data(struct vf610_adc *info) {
> >> + int result;
> >> +
> >> + result = readl(info->regs + ADC_R0);
> >> +
> >> + switch (info->adc_feature.res_mode) {
> >
> >maybe a lookup table could be used; value of res_mode is trusted at this point,
> >no error checking needed
>
> Yes, there don't need to check error.
> The entry number is only three, so lookup table is not valuable.
>
> >
> >> + case 8:
> >> + result &= VF610_ADC_DATA_BIT8_MASK;
> >> + break;
> >> + case 10:
> >> + result &= VF610_ADC_DATA_BIT10_MASK;
> >> + break;
> >> + case 12:
> >> + result &= VF610_ADC_DATA_BIT12_MASK;
> >> + break;
> >> + default:
> >> + dev_err(info->dev, "error resolution mode\n");
> >> + break;
> >> + }
> >> +
> >> + return result;
> >> +}
> >> +
> >> +static irqreturn_t vf610_adc_isr(int irq, void *dev_id) {
> >> + struct vf610_adc *info = (struct vf610_adc *)dev_id;
> >> + int coco;
> >> +
> >> + coco = readl(info->regs + ADC_HS);
> >> + if (coco & VF610_ADC_HS_COCO0) {
> >> + info->value = vf610_adc_read_data(info);
> >> + complete(&info->completion);
> >> + }
> >> +
> >> + return IRQ_HANDLED;
> >> +}
> >> +
> >> +static int vf610_read_raw(struct iio_dev *indio_dev,
> >> + struct iio_chan_spec const *chan,
> >> + int *val,
> >> + int *val2,
> >> + long mask)
> >> +{
> >> + struct vf610_adc *info = iio_priv(indio_dev);
> >> + unsigned int hc_cfg;
> >> + unsigned long timeout;
> >> +
> >> + /* Check for invalid channel */
> >> + if (chan->channel > VF610_ADC_MAX_CHANS_NUM)
> >> + return -EINVAL;
> >
> >should never happen
> >
> Got it. Thanks!
>
> >> +
> >> + switch (mask) {
> >> + case IIO_CHAN_INFO_RAW:
> >> + mutex_lock(&indio_dev->mlock);
> >> +
> >> + hc_cfg = VF610_ADC_ADCHC(chan->channel);
> >> + hc_cfg |= VF610_ADC_AIEN;
> >> + writel(hc_cfg, info->regs + ADC_HC0);
> >> + timeout = wait_for_completion_interruptible_timeout
> >> + (&info->completion, VF610_ADC_TIMEOUT);
> >> + *val = info->value;
> >> +
> >> + mutex_unlock(&indio_dev->mlock);
> >> +
> >> + if (timeout == 0)
> >> + return -ETIMEDOUT;
> >> +
> >> + return IIO_VAL_INT;
> >> +
> >> + case IIO_CHAN_INFO_SCALE:
> >> + *val = info->vref_uv >> info->adc_feature.res_mode;
> >> + *val2 = 0;
> >
> >use IIO_VAL_FRACTIONAL_LOG2 probably
>
> Yes, it is better to use IIO_VAL_FRACTIONAL_LOG2, thanks!
> >
> >> + return IIO_VAL_INT_PLUS_MICRO;
> >> + default:
> >> + break;
> >> + }
> >> +
> >> + return -EINVAL;
> >> +}
> >> +
> >> +static int vf610_adc_reg_access(struct iio_dev *indio_dev,
> >> + unsigned reg, unsigned writeval,
> >> + unsigned *readval)
> >> +{
> >> + struct vf610_adc *info = iio_priv(indio_dev);
> >> +
> >> + if (readval == NULL)
> >> + return -EINVAL;
> >
> >can this ever happen?
>
> No, it never happen. Thanks.
see Lars comment; I was wrong
I think reg should be range checked in addition
> static ssize_t iio_debugfs_read_reg(struct file *file, char __user *userbuf,
> size_t count, loff_t *ppos)
> {
> struct iio_dev *indio_dev = file->private_data;
> char buf[20];
> unsigned val = 0;
> ssize_t len;
> int ret;
>
> ret = indio_dev->info->debugfs_reg_access(indio_dev,
> indio_dev->cached_reg_addr,
> 0, &val);
> ...
> }
>
> >
> >I'd rather check the value of reg
> >> +
> >> + *readval = readl(info->regs + reg);
> >> +
> >> + return 0;
> >> +}
> >> +
> >> +static const struct iio_info vf610_adc_iio_info = {
> >> + .read_raw = &vf610_read_raw,
> >> + .debugfs_reg_access = &vf610_adc_reg_access,
> >> + .driver_module = THIS_MODULE,
> >> +};
> >> +
> >> +static const struct of_device_id vf610_adc_match[] = {
> >> + { .compatible = "fsl,vf610-adc", },
> >> + { /* sentinel */ }
> >> +};
> >> +MODULE_DEVICE_TABLE(of, vf610_adc_dt_ids);
> >> +
> >> +static int vf610_adc_probe(struct platform_device *pdev) {
> >> + struct vf610_adc *info = NULL;
> >> + struct iio_dev *indio_dev;
> >> + struct resource *mem;
> >> + int ret = -ENODEV;
> >
> >initialization of ret and info not needed
>
> Got it.
> >
> >> +
> >> + indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(struct vf610_adc));
> >> + if (!indio_dev) {
> >> + dev_err(&pdev->dev, "Failed allocating iio device\n");
> >> + return -ENOMEM;
> >> + }
> >> +
> >> + info = iio_priv(indio_dev);
> >> + info->dev = &pdev->dev;
> >> +
> >> + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> >> + info->regs = devm_ioremap_resource(&pdev->dev, mem);
> >> + if (IS_ERR(info->regs))
> >> + return PTR_ERR(info->regs);
> >> +
> >> + info->irq = platform_get_irq(pdev, 0);
> >> + if (info->irq < 0) {
> >> + dev_err(&pdev->dev, "no irq resource?\n");
> >> + return -EINVAL;
> >> + }
> >> +
> >> + ret = devm_request_irq(info->dev, info->irq,
> >> + vf610_adc_isr, 0,
> >> + dev_name(&pdev->dev), info);
> >> + if (ret < 0) {
> >> + dev_err(&pdev->dev, "failed requesting irq, irq = %d\n",
> >> + info->irq);
> >> + return ret;
> >> + }
> >> +
> >> + info->clk = devm_clk_get(&pdev->dev, "adc");
> >> + if (IS_ERR(info->clk)) {
> >> + dev_err(&pdev->dev, "failed getting clock, err = %ld\n",
> >> + PTR_ERR(info->clk));
> >> + ret = PTR_ERR(info->clk);
> >> + return ret;
> >> + }
> >> +
> >> + info->vref = devm_regulator_get(&pdev->dev, "vref");
> >> + if (!IS_ERR(info->vref)) {
> >> + ret = regulator_enable(info->vref);
> >> + if (ret) {
> >> + dev_err(&pdev->dev,
> >> + "Failed to enable vref regulator: %d\n", ret);
> >> + return ret;
> >> + }
> >> + } else {
> >> + info->vref = NULL;
> >> + }
> >> +
> >> + platform_set_drvdata(pdev, indio_dev);
> >> +
> >> + init_completion(&info->completion);
> >> +
> >> + indio_dev->name = dev_name(&pdev->dev);
> >> + indio_dev->dev.parent = &pdev->dev;
> >> + indio_dev->dev.of_node = pdev->dev.of_node;
> >> + indio_dev->info = &vf610_adc_iio_info;
> >> + indio_dev->modes = INDIO_DIRECT_MODE;
> >> + indio_dev->channels = vf610_adc_iio_channels;
> >> + indio_dev->num_channels = ARRAY_SIZE(vf610_adc_iio_channels);
> >> +
> >> + ret = devm_iio_device_register(&pdev->dev, indio_dev);
> >> + if (ret)
> >
> >regulator stays enabled
> >
> >> + return ret;
> >> +
> >> + ret = clk_prepare_enable(info->clk);
> >> + if (ret) {
> >> + dev_err(&pdev->dev,
> >> + "Could not prepare or enable the clock.\n");
> >> + return ret;
> >> + }
> >> +
> >> + vf610_adc_cfg_of_init(info);
> >> + vf610_adc_hw_init(info);
> >> +
> >> + return 0;
> >> +}
> >> +
> >> +static int vf610_adc_remove(struct platform_device *pdev) {
> >> + struct iio_dev *indio_dev = platform_get_drvdata(pdev);
> >> + struct vf610_adc *info = iio_priv(indio_dev);
> >> +
> >> + if (info->vref)
> >> + regulator_disable(info->vref);
> >> + clk_disable_unprepare(info->clk);
> >> +
> >> + return 0;
> >> +}
> >> +
> >> +#ifdef CONFIG_PM_SLEEP
> >> +static int vf610_adc_suspend(struct device *dev) {
> >> + struct iio_dev *indio_dev = dev_get_drvdata(dev);
> >> + struct vf610_adc *info = iio_priv(indio_dev);
> >> + int hc_cfg;
> >> +
> >> + /* enter to stop mode */
> >
> >comment does not add to clarity of the code, remove?
>
> Below code let ADC enter to stop mode when suspend.
yes; VF610_ADC_CONV_DISABLE is pretty descriptive on its own :)
> >
> >> + hc_cfg = readl(info->regs + ADC_HC0);
> >> + hc_cfg |= VF610_ADC_CONV_DISABLE;
> >> + writel(hc_cfg, info->regs + ADC_HC0);
> >> +
> >> + clk_disable_unprepare(info->clk);
> >> + if (info->vref)
> >> + regulator_disable(info->vref);
> >> +
> >> + return 0;
> >> +}
> >> +
> >> +static int vf610_adc_resume(struct device *dev) {
> >> + struct iio_dev *indio_dev = dev_get_drvdata(dev);
> >> + struct vf610_adc *info = iio_priv(indio_dev);
> >> + int ret;
> >> +
> >> + if (info->vref) {
> >> + ret = regulator_enable(info->vref);
> >> + if (ret)
> >> + return ret;
> >> + }
> >> +
> >> + ret = clk_prepare_enable(info->clk);
> >> + if (ret)
> >> + return ret;
> >> +
> >> + vf610_adc_hw_init(info);
> >> +
> >> + return 0;
> >> +}
> >> +#endif
> >> +
> >> +static SIMPLE_DEV_PM_OPS(vf610_adc_pm_ops,
> >> + vf610_adc_suspend,
> >> + vf610_adc_resume);
> >> +
> >> +static struct platform_driver vf610_adc_driver = {
> >> + .probe = vf610_adc_probe,
> >> + .remove = vf610_adc_remove,
> >> + .driver = {
> >> + .name = DRIVER_NAME,
> >> + .owner = THIS_MODULE,
> >> + .of_match_table = vf610_adc_match,
> >> + .pm = &vf610_adc_pm_ops,
> >> + },
> >> +};
> >> +
> >> +module_platform_driver(vf610_adc_driver);
> >> +
> >> +MODULE_AUTHOR("Fugang Duan <B38611@xxxxxxxxxxxxx>");
> >> +MODULE_DESCRIPTION("Freescale VF610 ADC driver"); MODULE_LICENSE("GPL
> >> +v2");
> >>
>
> Peter,
> thanks for your review.
>
> --
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>
--
Peter Meerwald
+43-664-2444418 (mobile)
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