Re: [PATCH 1/2] arm64: dma_mapping: allow PCI host driver to limit DMA mask
Hello! On 12/29/2016 11:45 PM, Nikita Yushchenko wrote: It is possible that PCI device supports 64-bit DMA addressing, and thus it's driver sets device's dma_mask to DMA_BIT_MASK(64), however PCI host Its. bridge has limitations on inbound transactions addressing. Example of such setup is NVME Isn't it called NVMe? SSD device connected to RCAR PCIe controller. R=Car. Previously there was attempt to handle this via bus notifier: after driver is attached to PCI device, bridge driver gets notifier callback, and resets dma_mask from there. However, this is racy: PCI device driver could already allocate buffers and/or start i/o in probe routine. In NVME case, i/o is started in workqueue context, and this race gives "sometimes works, sometimes not" effect. Proper solution should make driver's dma_set_mask() call to fail if host bridge can't support mask being set. This patch makes __swiotlb_dma_supported() to check mask being set for "To" not needed here. PCI device against dma_mask of struct device corresponding to PCI host bridge (one with name "pci:YY"), if that dma_mask is set. This is the least destructive approach: currently dma_mask of that device object is not used anyhow, thus all existing setups will work as before, and modification is required only in actually affected components - driver of particular PCI host bridge, and dma_map_ops of particular platform. Signed-off-by: Nikita Yushchenko --- arch/arm64/mm/dma-mapping.c | 11 +++ 1 file changed, 11 insertions(+) diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c index 290a84f..49645277 100644 --- a/arch/arm64/mm/dma-mapping.c +++ b/arch/arm64/mm/dma-mapping.c [...] @@ -347,6 +348,16 @@ static int __swiotlb_get_sgtable(struct device *dev, struct sg_table *sgt, static int __swiotlb_dma_supported(struct device *hwdev, u64 mask) { +#ifdef CONFIG_PCI + if (dev_is_pci(hwdev)) { + struct pci_dev *pdev = to_pci_dev(hwdev); + struct pci_host_bridge *br = pci_find_host_bridge(pdev->bus); + + if (br->dev.dma_mask && (*br->dev.dma_mask) && + (mask & (*br->dev.dma_mask)) != mask) Hum, inner parens not necessary? [...] MBR, Sergei
Re: [PATCH 1/2] arm64: dma_mapping: allow PCI host driver to limit DMA mask
On 12/30/2016 12:46 PM, Sergei Shtylyov wrote: It is possible that PCI device supports 64-bit DMA addressing, and thus it's driver sets device's dma_mask to DMA_BIT_MASK(64), however PCI host Its. bridge has limitations on inbound transactions addressing. Example of such setup is NVME Isn't it called NVMe? SSD device connected to RCAR PCIe controller. R=Car. Sorry, R-Car. :-) [...] MBR, Sergei
Re: [PATCHv2] iio: adc: Add Maxim MAX11100 driver
On 13/12/16 12:37, Jacopo Mondi wrote: > Add IIO driver for Maxim MAX11100 single-channel ADC. > Add DT bindings documentation. > > Signed-off-by: Jacopo Mondi A quick process related thing. Please don't post a new version of a driver as a reply to an old version. It very rapidly leads to deep and difficult to follow threads. Much easier to just start a new thread. > --- > > v1 -> v2: > - incorporated pmeerw's review comments > - retrieve vref from dts and use that to convert read_raw result > to mV > - add device tree bindings documentation > > --- > .../devicetree/bindings/iio/adc/max11100.txt | 17 +++ > drivers/iio/adc/Kconfig| 9 ++ > drivers/iio/adc/Makefile | 1 + > drivers/iio/adc/max11100.c | 166 > + > 4 files changed, 193 insertions(+) > create mode 100644 Documentation/devicetree/bindings/iio/adc/max11100.txt > create mode 100644 drivers/iio/adc/max11100.c > > diff --git a/Documentation/devicetree/bindings/iio/adc/max11100.txt > b/Documentation/devicetree/bindings/iio/adc/max11100.txt > new file mode 100644 > index 000..6877c11 > --- /dev/null > +++ b/Documentation/devicetree/bindings/iio/adc/max11100.txt > @@ -0,0 +1,17 @@ > +* Maxim max11100 Analog to Digital Converter (ADC) > + > +Required properties: > + - compatible: Should be "maxim,max11100" > + - vref-supply: phandle to the regulator that provides reference voltage > + > +Optional properties: > + - spi-max-frequency: SPI maximum frequency > + > +Example: > + > +adc0: max11100@0 { > +compatible = "maxim,max11100"; > +vref-supply = <&adc0_vref>; > +spi-max-frequency = <24>; > +}; > + > diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig > index 99c0514..a909484 100644 > --- a/drivers/iio/adc/Kconfig > +++ b/drivers/iio/adc/Kconfig > @@ -285,6 +285,15 @@ config MAX1027 > To compile this driver as a module, choose M here: the module will be > called max1027. > > +config MAX11100 > + tristate "Maxim max11100 ADC driver" > + depends on SPI > + help > + Say yes here to build support for Maxim max11100 SPI ADC > + > + To compile this driver as a module, choose M here: the module will be > + called max11100. > + > config MAX1363 > tristate "Maxim max1363 ADC driver" > depends on I2C > diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile > index 7a40c04..1463044 100644 > --- a/drivers/iio/adc/Makefile > +++ b/drivers/iio/adc/Makefile > @@ -29,6 +29,7 @@ obj-$(CONFIG_LP8788_ADC) += lp8788_adc.o > obj-$(CONFIG_LPC18XX_ADC) += lpc18xx_adc.o > obj-$(CONFIG_LTC2485) += ltc2485.o > obj-$(CONFIG_MAX1027) += max1027.o > +obj-$(CONFIG_MAX11100) += max11100.o > obj-$(CONFIG_MAX1363) += max1363.o > obj-$(CONFIG_MCP320X) += mcp320x.o > obj-$(CONFIG_MCP3422) += mcp3422.o > diff --git a/drivers/iio/adc/max11100.c b/drivers/iio/adc/max11100.c > new file mode 100644 > index 000..f372ad8 > --- /dev/null > +++ b/drivers/iio/adc/max11100.c > @@ -0,0 +1,166 @@ > +/* > + * iio/adc/max11100.c > + * Maxim max11100 ADC Driver with IIO interface > + * > + * Copyright (C) 2016 Renesas Electronics Corporation > + * Copyright (C) 2016 Jacopo Mondi > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License version 2 as > + * published by the Free Software Foundation. > + */ > +#include > +#include > +#include > +#include > +#include > + > +#include > +#include > +#include > + > +/* > + * LSB is the ADC single digital step > + * 1 LSB = (vref / 2 ^ 16) > + * AIN = (DIN * LSB) > + */ > +#define MAX11100_LSB_DIV (1 << 16) > +#define MAX11100_LSB(vref) (vref / MAX11100_LSB_DIV) > + > +struct max11100_state { > + const struct max11100_chip_desc *desc; > + struct spi_device *spi; > + int vref_uv; > + struct mutex lock; > +}; > + > +static struct iio_chan_spec max11100_channels[] = { > + { /* [0] */ > + .type = IIO_VOLTAGE, > + .scan_type = { > + .sign = 'u', > + .realbits = 16, > + .storagebits = 24, > + .shift = 8, > + .repeat = 1, > + .endianness = IIO_BE, > + }, > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), > + }, > +}; > + > +static struct max11100_chip_desc { > + unsigned int num_chan; > + const struct iio_chan_spec *channels; > +} max11100_desc = { > + .num_chan = ARRAY_SIZE(max11100_channels), > + .channels = max11100_channels, > +}; > + > +static int max11100_read_raw(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan, > + int *val, int *val2, long mask) > +{ > + int ret; > + struct max11100_state *state = iio_priv(indio_d
Re: [PATCHv2] iio: adc: Add Maxim MAX11100 driver
On 13/12/16 15:53, Wolfram Sang wrote: > >>> +struct max11100_state { >>> + const struct max11100_chip_desc *desc; >>> + struct spi_device *spi; >>> + int vref_uv; >> >> unsi >> It's good practice to move the smaller members to the end of the structure, >> to avoid gaps due to alignment rules (struct mutex needs to be 64-bit aligned >> on 64-bit platforms). > > One option. Another idea is to put the most used members to the front to > increase chances of being in the same cacheline. > Or more cynically, just put them in the order that makes most logical sense as that gives you fewest grumpy reviewers. We aren't really talking high performance stuff here! Jonathan
Re: [PATCHv2] iio: adc: Add Maxim MAX11100 driver
On 14/12/16 12:00, jac...@jmondi.org wrote: > Hello Peter, >thanks for review > > On 13/12/2016 21:33, Peter Meerwald-Stadler wrote: >> >>> Add IIO driver for Maxim MAX11100 single-channel ADC. >>> Add DT bindings documentation. >> >> some more comments >> >>> Signed-off-by: Jacopo Mondi >>> --- >>> >>> v1 -> v2: >>> - incorporated pmeerw's review comments >>> - retrieve vref from dts and use that to convert read_raw result >>> to mV >>> - add device tree bindings documentation >>> >>> --- >>> .../devicetree/bindings/iio/adc/max11100.txt | 17 +++ >>> drivers/iio/adc/Kconfig| 9 ++ >>> drivers/iio/adc/Makefile | 1 + >>> drivers/iio/adc/max11100.c | 166 >>> + >>> 4 files changed, 193 insertions(+) >>> create mode 100644 Documentation/devicetree/bindings/iio/adc/max11100.txt >>> create mode 100644 drivers/iio/adc/max11100.c >>> >>> diff --git a/Documentation/devicetree/bindings/iio/adc/max11100.txt >>> b/Documentation/devicetree/bindings/iio/adc/max11100.txt >>> new file mode 100644 >>> index 000..6877c11 >>> --- /dev/null >>> +++ b/Documentation/devicetree/bindings/iio/adc/max11100.txt >>> @@ -0,0 +1,17 @@ >>> +* Maxim max11100 Analog to Digital Converter (ADC) >>> + >>> +Required properties: >>> + - compatible: Should be "maxim,max11100" >>> + - vref-supply: phandle to the regulator that provides reference voltage >>> + >>> +Optional properties: >>> + - spi-max-frequency: SPI maximum frequency >>> + >>> +Example: >>> + >>> +adc0: max11100@0 { >>> +compatible = "maxim,max11100"; >>> +vref-supply = <&adc0_vref>; >>> +spi-max-frequency = <24>; >>> +}; >>> + >>> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig >>> index 99c0514..a909484 100644 >>> --- a/drivers/iio/adc/Kconfig >>> +++ b/drivers/iio/adc/Kconfig >>> @@ -285,6 +285,15 @@ config MAX1027 >>>To compile this driver as a module, choose M here: the module will be >>>called max1027. >>> >>> +config MAX11100 >>> +tristate "Maxim max11100 ADC driver" >>> +depends on SPI >> >> SPI_MASTER is more precise I think >> >>> +help >>> + Say yes here to build support for Maxim max11100 SPI ADC >>> + >>> + To compile this driver as a module, choose M here: the module will be >>> + called max11100. >>> + >>> config MAX1363 >>> tristate "Maxim max1363 ADC driver" >>> depends on I2C >>> diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile >>> index 7a40c04..1463044 100644 >>> --- a/drivers/iio/adc/Makefile >>> +++ b/drivers/iio/adc/Makefile >>> @@ -29,6 +29,7 @@ obj-$(CONFIG_LP8788_ADC) += lp8788_adc.o >>> obj-$(CONFIG_LPC18XX_ADC) += lpc18xx_adc.o >>> obj-$(CONFIG_LTC2485) += ltc2485.o >>> obj-$(CONFIG_MAX1027) += max1027.o >>> +obj-$(CONFIG_MAX11100) += max11100.o >>> obj-$(CONFIG_MAX1363) += max1363.o >>> obj-$(CONFIG_MCP320X) += mcp320x.o >>> obj-$(CONFIG_MCP3422) += mcp3422.o >>> diff --git a/drivers/iio/adc/max11100.c b/drivers/iio/adc/max11100.c >>> new file mode 100644 >>> index 000..f372ad8 >>> --- /dev/null >>> +++ b/drivers/iio/adc/max11100.c >>> @@ -0,0 +1,166 @@ >>> +/* >>> + * iio/adc/max11100.c >>> + * Maxim max11100 ADC Driver with IIO interface >>> + * >>> + * Copyright (C) 2016 Renesas Electronics Corporation >>> + * Copyright (C) 2016 Jacopo Mondi >>> + * >>> + * This program is free software; you can redistribute it and/or modify >>> + * it under the terms of the GNU General Public License version 2 as >>> + * published by the Free Software Foundation. >>> + */ >>> +#include >>> +#include >>> +#include >>> +#include >>> +#include >>> + >>> +#include >>> +#include >>> +#include >>> + >>> +/* >>> + * LSB is the ADC single digital step >>> + * 1 LSB = (vref / 2 ^ 16) >>> + * AIN = (DIN * LSB) >>> + */ >>> +#define MAX11100_LSB_DIV(1 << 16) >>> +#define MAX11100_LSB(vref) (vref / MAX11100_LSB_DIV) >> >> maybe parenthesis around vref >> >>> + >>> +struct max11100_state { >>> +const struct max11100_chip_desc *desc; >>> +struct spi_device *spi; >>> +int vref_uv; >>> +struct mutex lock; >>> +}; >>> + >>> +static struct iio_chan_spec max11100_channels[] = { >>> +{ /* [0] */ >>> +.type = IIO_VOLTAGE, >>> +.scan_type = { >> >> scan_type not needed since driver does not support buffered reads >> >>> +.sign = 'u', >>> +.realbits = 16, >>> +.storagebits = 24, >>> +.shift = 8, >>> +.repeat = 1, >>> +.endianness = IIO_BE, >>> +}, >>> +.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), >>> +}, >>> +}; >>> + >>> +static struct max11100_chip_desc { >>> +unsigned int num_chan; >>> +const struct iio_chan_spec *channels; >>> +} max11100_desc = { >>> +.num_chan = ARRAY_SIZE(max11100_channels), >>> +.channels = max11100_channels, >>> +}; >>> + >>> +sta
Re: [PATCHv2] iio: adc: Add Maxim MAX11100 driver
On 13/12/16 12:37, Jacopo Mondi wrote: > Add IIO driver for Maxim MAX11100 single-channel ADC. > Add DT bindings documentation. > > Signed-off-by: Jacopo Mondi Nothing significant to add, but a few comments inline. Jonathan > --- > > v1 -> v2: > - incorporated pmeerw's review comments > - retrieve vref from dts and use that to convert read_raw result > to mV > - add device tree bindings documentation > > --- > .../devicetree/bindings/iio/adc/max11100.txt | 17 +++ > drivers/iio/adc/Kconfig| 9 ++ > drivers/iio/adc/Makefile | 1 + > drivers/iio/adc/max11100.c | 166 > + > 4 files changed, 193 insertions(+) > create mode 100644 Documentation/devicetree/bindings/iio/adc/max11100.txt > create mode 100644 drivers/iio/adc/max11100.c > > diff --git a/Documentation/devicetree/bindings/iio/adc/max11100.txt > b/Documentation/devicetree/bindings/iio/adc/max11100.txt > new file mode 100644 > index 000..6877c11 > --- /dev/null > +++ b/Documentation/devicetree/bindings/iio/adc/max11100.txt > @@ -0,0 +1,17 @@ > +* Maxim max11100 Analog to Digital Converter (ADC) > + > +Required properties: > + - compatible: Should be "maxim,max11100" > + - vref-supply: phandle to the regulator that provides reference voltage > + > +Optional properties: > + - spi-max-frequency: SPI maximum frequency > + > +Example: > + > +adc0: max11100@0 { > +compatible = "maxim,max11100"; > +vref-supply = <&adc0_vref>; > +spi-max-frequency = <24>; > +}; > + > diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig > index 99c0514..a909484 100644 > --- a/drivers/iio/adc/Kconfig > +++ b/drivers/iio/adc/Kconfig > @@ -285,6 +285,15 @@ config MAX1027 > To compile this driver as a module, choose M here: the module will be > called max1027. > > +config MAX11100 > + tristate "Maxim max11100 ADC driver" > + depends on SPI > + help > + Say yes here to build support for Maxim max11100 SPI ADC > + > + To compile this driver as a module, choose M here: the module will be > + called max11100. > + > config MAX1363 > tristate "Maxim max1363 ADC driver" > depends on I2C > diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile > index 7a40c04..1463044 100644 > --- a/drivers/iio/adc/Makefile > +++ b/drivers/iio/adc/Makefile > @@ -29,6 +29,7 @@ obj-$(CONFIG_LP8788_ADC) += lp8788_adc.o > obj-$(CONFIG_LPC18XX_ADC) += lpc18xx_adc.o > obj-$(CONFIG_LTC2485) += ltc2485.o > obj-$(CONFIG_MAX1027) += max1027.o > +obj-$(CONFIG_MAX11100) += max11100.o > obj-$(CONFIG_MAX1363) += max1363.o > obj-$(CONFIG_MCP320X) += mcp320x.o > obj-$(CONFIG_MCP3422) += mcp3422.o > diff --git a/drivers/iio/adc/max11100.c b/drivers/iio/adc/max11100.c > new file mode 100644 > index 000..f372ad8 > --- /dev/null > +++ b/drivers/iio/adc/max11100.c > @@ -0,0 +1,166 @@ > +/* > + * iio/adc/max11100.c > + * Maxim max11100 ADC Driver with IIO interface > + * > + * Copyright (C) 2016 Renesas Electronics Corporation > + * Copyright (C) 2016 Jacopo Mondi > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License version 2 as > + * published by the Free Software Foundation. > + */ > +#include > +#include > +#include > +#include > +#include > + > +#include > +#include > +#include > + > +/* > + * LSB is the ADC single digital step > + * 1 LSB = (vref / 2 ^ 16) > + * AIN = (DIN * LSB) > + */ > +#define MAX11100_LSB_DIV (1 << 16) > +#define MAX11100_LSB(vref) (vref / MAX11100_LSB_DIV) > + > +struct max11100_state { > + const struct max11100_chip_desc *desc; > + struct spi_device *spi; > + int vref_uv; > + struct mutex lock; > +}; > + > +static struct iio_chan_spec max11100_channels[] = { > + { /* [0] */ > + .type = IIO_VOLTAGE, > + .scan_type = { > + .sign = 'u', > + .realbits = 16, > + .storagebits = 24, > + .shift = 8, > + .repeat = 1, > + .endianness = IIO_BE, > + }, > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), > + }, > +}; > + > +static struct max11100_chip_desc { > + unsigned int num_chan; > + const struct iio_chan_spec *channels; > +} max11100_desc = { > + .num_chan = ARRAY_SIZE(max11100_channels), > + .channels = max11100_channels, > +}; > + > +static int max11100_read_raw(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan, > + int *val, int *val2, long mask) > +{ > + int ret; > + struct max11100_state *state = iio_priv(indio_dev); > + uint8_t buffer[3]; > + > + mutex_lock(&state->lock); > + > + ret = spi_read(state->spi, buffer, sizeof(buffer)); > + if (