| Message ID | 20191003091636.21060-1-kamel.bouhara@bootlin.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] soc: at91: Add Atmel SFR SN (Serial Number) support | expand |
Hi, Kamel, On 10/03/2019 12:16 PM, Kamel Bouhara wrote: > External E-Mail > > > Add support to read SFR's read-only registers providing the SoC > Serial Numbers (SN0+SN1) to userspace. > > ~ # hexdump -n 8 -e'"%d\n"' /sys/bus/nvmem/devices/atmel-sfr0/nvmem > 959527243 > 371539274 > > Signed-off-by: Kamel Bouhara <kamel.bouhara@bootlin.com> > --- > Changes in v2: > - updated atmel-sfr.c to sfr.c in Makefile > - fixed missing drvdata struct definition > - added missing syscon header > > drivers/soc/atmel/Kconfig | 11 ++++ > drivers/soc/atmel/Makefile | 1 + > drivers/soc/atmel/sfr.c | 116 +++++++++++++++++++++++++++++++++++++ > 3 files changed, 128 insertions(+) > create mode 100644 drivers/soc/atmel/sfr.c > > diff --git a/drivers/soc/atmel/Kconfig b/drivers/soc/atmel/Kconfig > index 05528139b023..d61711cb9556 100644 > --- a/drivers/soc/atmel/Kconfig > +++ b/drivers/soc/atmel/Kconfig > @@ -5,3 +5,14 @@ config AT91_SOC_ID > default ARCH_AT91 > help > Include support for the SoC bus on the Atmel ARM SoCs. > + > +config AT91_SOC_SFR > + tristate "Special Function Registers support" > + depends on ARCH_AT91 || COMPILE_TEST > + help > + This is a driver for the Special Function Registers available on > + Atmel SAMA5Dx SoCs, providing access to specific aspects of the > + integrated memory, bridge implementations, proccessor etc. typo: processor. > + > + This driver can also be built as a module. If so, the module > + will be called sfr. > diff --git a/drivers/soc/atmel/Makefile b/drivers/soc/atmel/Makefile > index 7ca355d10553..d849a897cd77 100644 > --- a/drivers/soc/atmel/Makefile > +++ b/drivers/soc/atmel/Makefile > @@ -1,2 +1,3 @@ > # SPDX-License-Identifier: GPL-2.0-only > obj-$(CONFIG_AT91_SOC_ID) += soc.o > +obj-$(CONFIG_AT91_SOC_SFR) += sfr.o > diff --git a/drivers/soc/atmel/sfr.c b/drivers/soc/atmel/sfr.c > new file mode 100644 > index 000000000000..2be306157283 > --- /dev/null > +++ b/drivers/soc/atmel/sfr.c > @@ -0,0 +1,116 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * sfr.c - driver for special function registers > + * > + * Copyright (C) 2019 Bootlin. > + * > + */ > +#include <linux/device.h> > +#include <linux/mfd/syscon.h> > +#include <linux/module.h> > +#include <linux/nvmem-provider.h> > +#include <linux/of.h> > +#include <linux/of_device.h> > +#include <linux/platform_device.h> > +#include <linux/regmap.h> > + > +#define SFR_SN0 0x4c > + > +struct sfr_priv { how about renaming this to struct atmel_sfr_priv? > + struct device *dev; this is not used, maybe you can drop it? > + struct regmap *regmap; > + struct nvmem_config *config; > + struct atmel_sfr_drvdata *drvdata; this is not used, maybe you can drop it? > +}; > + > +struct atmel_sfr_drvdata { > + unsigned int nregs; > +}; > + > +static int atmel_sfr_read(void *context, unsigned int offset, > + void *buf, size_t bytes) > +{ > + struct sfr_priv *priv = context; > + struct atmel_sfr_drvdata *drvdata = priv->drvdata; looks like you can drop the *drvdata local variable. > + > + return regmap_bulk_read(priv->regmap, SFR_SN0 + offset, > + buf, bytes / 4); > +} > + > +static struct nvmem_config atmel_sfr_nvmem_config = { > + .name = "atmel-sfr", > + .read_only = true, > + .word_size = 4, > + .stride = 4, > + .reg_read = atmel_sfr_read, > +}; > + > +static int atmel_sfr_probe(struct platform_device *pdev) > +{ > + struct device *dev = &pdev->dev; > + struct device_node *np = dev->of_node; > + struct sfr_priv *priv; > + struct nvmem_device *nvmem; > + const struct atmel_sfr_drvdata *drvdata; > + > + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); zeroing should not be needed since you update all the priv fields below. > + if (!priv) > + return -ENOMEM; > + > + drvdata = of_device_get_match_data(dev); > + if (!drvdata) > + return -EINVAL; > + > + priv->regmap = syscon_node_to_regmap(np); > + if (IS_ERR(priv->regmap)) { > + dev_err(dev, "cannot get parent's regmap\n"); > + return PTR_ERR(priv->regmap); > + } > + > + priv->drvdata = drvdata; not needed? Cheers, ta > + > + atmel_sfr_nvmem_config.size = drvdata->nregs; > + atmel_sfr_nvmem_config.dev = dev; > + atmel_sfr_nvmem_config.priv = priv; > + > + priv->config = &atmel_sfr_nvmem_config; > + > + nvmem = devm_nvmem_register(dev, &atmel_sfr_nvmem_config); > + if (IS_ERR(nvmem)) { > + dev_err(dev, "error registering nvmem config\n"); > + return PTR_ERR(nvmem); > + } > + > + return 0; > +} > + > +static struct atmel_sfr_drvdata sama5d2_sama5d4_drvdata = { > + .nregs = 2 * 4, > +}; > + > +static const struct of_device_id atmel_sfr_dt_ids[] = { > + { > + .compatible = "atmel,sama5d2-sfr", > + .data = &sama5d2_sama5d4_drvdata, > + }, { > + .compatible = "atmel,sama5d4-sfr", > + .data = &sama5d2_sama5d4_drvdata, > + }, { > + /* sentinel */ > + }, > +}; > +MODULE_DEVICE_TABLE(of, atmel_sfr_dt_ids); > + > +static struct platform_driver atmel_sfr_driver = { > + .probe = atmel_sfr_probe, > + .driver = { > + .name = "atmel-sfr", > + .of_match_table = atmel_sfr_dt_ids, > + }, > +}; > +module_platform_driver(atmel_sfr_driver); > + > +MODULE_AUTHOR("Kamel Bouhara <kamel.bouhara@bootlin.com>"); > +MODULE_DESCRIPTION("Atmel SFR SN driver for SAMA5D2/4 SoC family"); > +MODULE_LICENSE("GPL v2"); > + > -- > 2.23.0 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel > >
On 10/03/2019 12:40 PM, Tudor.Ambarus@microchip.com wrote: cut > > how about renaming this to struct atmel_sfr_priv? > >> + struct device *dev; > > this is not used, maybe you can drop it? > >> + struct regmap *regmap; >> + struct nvmem_config *config; where is priv->config used? >> + struct atmel_sfr_drvdata *drvdata; > > this is not used, maybe you can drop it? > >> +}; cut >> +static struct atmel_sfr_drvdata sama5d2_sama5d4_drvdata = { struct should be const. And I'm not sure about the sama5d2_sama5d4 naming. Maybe choose "5d4_drvdata" and use it for 5d2 too? Maybe Nicolas has a preference here. Thanks, ta >> + .nregs = 2 * 4, >> +};
On 03/10/2019 at 11:50, Tudor Ambarus - M18064 wrote: > > > On 10/03/2019 12:40 PM, Tudor.Ambarus@microchip.com wrote: > cut > >> >> how about renaming this to struct atmel_sfr_priv? >> >>> + struct device *dev; >> >> this is not used, maybe you can drop it? >> >>> + struct regmap *regmap; >>> + struct nvmem_config *config; > > where is priv->config used? > >>> + struct atmel_sfr_drvdata *drvdata; >> >> this is not used, maybe you can drop it? >> >>> +}; > > cut > >>> +static struct atmel_sfr_drvdata sama5d2_sama5d4_drvdata = { > > struct should be const. And I'm not sure about the sama5d2_sama5d4 naming. Maybe > choose "5d4_drvdata" and use it for 5d2 too? Maybe Nicolas has a preference here. I'm not a big fan of "5d3/5d2/5d4" type of naming. If it appeared first in sama5d4, then this name ca be taken to describe sama5d2 reality as well => sama5d4_drvdata. Now it's dropped in v3: so we're good... >>> + .nregs = 2 * 4, >>> +};
Hello, On 10/3/19 2:06 PM, Nicolas.Ferre@microchip.com wrote: > On 03/10/2019 at 11:50, Tudor Ambarus - M18064 wrote: >> >> On 10/03/2019 12:40 PM, Tudor.Ambarus@microchip.com wrote: >> cut >> >>> how about renaming this to struct atmel_sfr_priv? >>> >>>> + struct device *dev; >>> this is not used, maybe you can drop it? >>> >>>> + struct regmap *regmap; >>>> + struct nvmem_config *config; >> where is priv->config used? >> >>>> + struct atmel_sfr_drvdata *drvdata; >>> this is not used, maybe you can drop it? >>> >>>> +}; >> cut >> >>>> +static struct atmel_sfr_drvdata sama5d2_sama5d4_drvdata = { >> struct should be const. And I'm not sure about the sama5d2_sama5d4 naming. Maybe >> choose "5d4_drvdata" and use it for 5d2 too? Maybe Nicolas has a preference here. > I'm not a big fan of "5d3/5d2/5d4" type of naming. If it appeared first > in sama5d4, then this name ca be taken to describe sama5d2 reality as > well => sama5d4_drvdata. > > Now it's dropped in v3: so we're good... Yes, thanks for the review. Kamel
diff --git a/drivers/soc/atmel/Kconfig b/drivers/soc/atmel/Kconfig index 05528139b023..d61711cb9556 100644 --- a/drivers/soc/atmel/Kconfig +++ b/drivers/soc/atmel/Kconfig @@ -5,3 +5,14 @@ config AT91_SOC_ID default ARCH_AT91 help Include support for the SoC bus on the Atmel ARM SoCs. + +config AT91_SOC_SFR + tristate "Special Function Registers support" + depends on ARCH_AT91 || COMPILE_TEST + help + This is a driver for the Special Function Registers available on + Atmel SAMA5Dx SoCs, providing access to specific aspects of the + integrated memory, bridge implementations, proccessor etc. + + This driver can also be built as a module. If so, the module + will be called sfr. diff --git a/drivers/soc/atmel/Makefile b/drivers/soc/atmel/Makefile index 7ca355d10553..d849a897cd77 100644 --- a/drivers/soc/atmel/Makefile +++ b/drivers/soc/atmel/Makefile @@ -1,2 +1,3 @@ # SPDX-License-Identifier: GPL-2.0-only obj-$(CONFIG_AT91_SOC_ID) += soc.o +obj-$(CONFIG_AT91_SOC_SFR) += sfr.o diff --git a/drivers/soc/atmel/sfr.c b/drivers/soc/atmel/sfr.c new file mode 100644 index 000000000000..2be306157283 --- /dev/null +++ b/drivers/soc/atmel/sfr.c @@ -0,0 +1,116 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * sfr.c - driver for special function registers + * + * Copyright (C) 2019 Bootlin. + * + */ +#include <linux/device.h> +#include <linux/mfd/syscon.h> +#include <linux/module.h> +#include <linux/nvmem-provider.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> + +#define SFR_SN0 0x4c + +struct sfr_priv { + struct device *dev; + struct regmap *regmap; + struct nvmem_config *config; + struct atmel_sfr_drvdata *drvdata; +}; + +struct atmel_sfr_drvdata { + unsigned int nregs; +}; + +static int atmel_sfr_read(void *context, unsigned int offset, + void *buf, size_t bytes) +{ + struct sfr_priv *priv = context; + struct atmel_sfr_drvdata *drvdata = priv->drvdata; + + return regmap_bulk_read(priv->regmap, SFR_SN0 + offset, + buf, bytes / 4); +} + +static struct nvmem_config atmel_sfr_nvmem_config = { + .name = "atmel-sfr", + .read_only = true, + .word_size = 4, + .stride = 4, + .reg_read = atmel_sfr_read, +}; + +static int atmel_sfr_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct device_node *np = dev->of_node; + struct sfr_priv *priv; + struct nvmem_device *nvmem; + const struct atmel_sfr_drvdata *drvdata; + + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + drvdata = of_device_get_match_data(dev); + if (!drvdata) + return -EINVAL; + + priv->regmap = syscon_node_to_regmap(np); + if (IS_ERR(priv->regmap)) { + dev_err(dev, "cannot get parent's regmap\n"); + return PTR_ERR(priv->regmap); + } + + priv->drvdata = drvdata; + + atmel_sfr_nvmem_config.size = drvdata->nregs; + atmel_sfr_nvmem_config.dev = dev; + atmel_sfr_nvmem_config.priv = priv; + + priv->config = &atmel_sfr_nvmem_config; + + nvmem = devm_nvmem_register(dev, &atmel_sfr_nvmem_config); + if (IS_ERR(nvmem)) { + dev_err(dev, "error registering nvmem config\n"); + return PTR_ERR(nvmem); + } + + return 0; +} + +static struct atmel_sfr_drvdata sama5d2_sama5d4_drvdata = { + .nregs = 2 * 4, +}; + +static const struct of_device_id atmel_sfr_dt_ids[] = { + { + .compatible = "atmel,sama5d2-sfr", + .data = &sama5d2_sama5d4_drvdata, + }, { + .compatible = "atmel,sama5d4-sfr", + .data = &sama5d2_sama5d4_drvdata, + }, { + /* sentinel */ + }, +}; +MODULE_DEVICE_TABLE(of, atmel_sfr_dt_ids); + +static struct platform_driver atmel_sfr_driver = { + .probe = atmel_sfr_probe, + .driver = { + .name = "atmel-sfr", + .of_match_table = atmel_sfr_dt_ids, + }, +}; +module_platform_driver(atmel_sfr_driver); + +MODULE_AUTHOR("Kamel Bouhara <kamel.bouhara@bootlin.com>"); +MODULE_DESCRIPTION("Atmel SFR SN driver for SAMA5D2/4 SoC family"); +MODULE_LICENSE("GPL v2"); +
Add support to read SFR's read-only registers providing the SoC Serial Numbers (SN0+SN1) to userspace. ~ # hexdump -n 8 -e'"%d\n"' /sys/bus/nvmem/devices/atmel-sfr0/nvmem 959527243 371539274 Signed-off-by: Kamel Bouhara <kamel.bouhara@bootlin.com> --- Changes in v2: - updated atmel-sfr.c to sfr.c in Makefile - fixed missing drvdata struct definition - added missing syscon header drivers/soc/atmel/Kconfig | 11 ++++ drivers/soc/atmel/Makefile | 1 + drivers/soc/atmel/sfr.c | 116 +++++++++++++++++++++++++++++++++++++ 3 files changed, 128 insertions(+) create mode 100644 drivers/soc/atmel/sfr.c -- 2.23.0