| Message ID | 1437783682-13632-4-git-send-email-moritz.fischer@ettus.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 07/25/2015 02:21 AM, Moritz Fischer wrote: > This adds a reset controller driver to control the Xilinx Zynq > SoC's various resets. > > Signed-off-by: Moritz Fischer <moritz.fischer@ettus.com> > --- > drivers/reset/Makefile | 1 + > drivers/reset/reset-zynq.c | 142 +++++++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 143 insertions(+) > create mode 100644 drivers/reset/reset-zynq.c > > diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile > index 157d421..3fe50e7 100644 > --- a/drivers/reset/Makefile > +++ b/drivers/reset/Makefile > @@ -3,3 +3,4 @@ obj-$(CONFIG_ARCH_SOCFPGA) += reset-socfpga.o > obj-$(CONFIG_ARCH_BERLIN) += reset-berlin.o > obj-$(CONFIG_ARCH_SUNXI) += reset-sunxi.o > obj-$(CONFIG_ARCH_STI) += sti/ > +obj-$(CONFIG_ARCH_ZYNQ) += reset-zynq.o > diff --git a/drivers/reset/reset-zynq.c b/drivers/reset/reset-zynq.c > new file mode 100644 > index 0000000..05e37f8 > --- /dev/null > +++ b/drivers/reset/reset-zynq.c > @@ -0,0 +1,142 @@ > +/* > + * Copyright (c) 2015, National Instruments Corp. > + * > + * Xilinx Zynq Reset controller driver > + * > + * 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; version 2 of the License. > + * > + * 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. > + */ > + > +#include <linux/err.h> > +#include <linux/io.h> > +#include <linux/module.h> > +#include <linux/mfd/syscon.h> > +#include <linux/of.h> > +#include <linux/platform_device.h> > +#include <linux/reset-controller.h> > +#include <linux/regmap.h> > +#include <linux/types.h> > + > +/* Offsets into SLCR regmap */ > +#define SLCR_RST_CTRL_OFFSET 0x200 /* FPGA Software Reset Control */ incorrect comment. > + > +#define NBANKS 18 > + > +struct zynq_reset_data { > + struct regmap *slcr; > + struct reset_controller_dev rcdev; > +}; > + > +#define to_zynq_reset_data(p) \ > + container_of((p), struct zynq_reset_data, rcdev) > + > +static int zynq_reset_assert(struct reset_controller_dev *rcdev, > + unsigned long id) > +{ > + struct zynq_reset_data *priv = to_zynq_reset_data(rcdev); > + > + int bank = id / BITS_PER_LONG; > + int offset = id % BITS_PER_LONG; > + > + regmap_update_bits(priv->slcr, > + SLCR_RST_CTRL_OFFSET + (bank * 4), > + BIT(offset), > + BIT(offset)); > + > + return 0; > +} > + > +static int zynq_reset_deassert(struct reset_controller_dev *rcdev, > + unsigned long id) > +{ > + struct zynq_reset_data *priv = to_zynq_reset_data(rcdev); > + > + int bank = id / BITS_PER_LONG; > + int offset = id % BITS_PER_LONG; > + > + regmap_update_bits(priv->slcr, > + SLCR_RST_CTRL_OFFSET + (bank * 4), > + BIT(offset), > + ~BIT(offset)); > + > + return 0; > +} > + > +static int zynq_reset_status(struct reset_controller_dev *rcdev, > + unsigned long id) > +{ > + struct zynq_reset_data *priv = to_zynq_reset_data(rcdev); > + > + int bank = id / BITS_PER_LONG; > + int offset = id % BITS_PER_LONG; > + u32 reg; > + > + regmap_read(priv->slcr, SLCR_RST_CTRL_OFFSET + (bank * 4), ®); > + > + return !(reg & BIT(offset)); > +} > + > +static const struct reset_control_ops zynq_reset_ops = { > + .assert = zynq_reset_assert, > + .deassert = zynq_reset_deassert, > + .status = zynq_reset_status, > +}; > + > +static int zynq_reset_probe(struct platform_device *pdev) > +{ > + struct zynq_reset_data *priv; > + > + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); > + if (!priv) > + return -ENOMEM; > + platform_set_drvdata(pdev, priv); > + > + priv->slcr = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, > + "syscon"); NIT - incorrect indentation. > + if (IS_ERR(priv->slcr)) { > + dev_err(&pdev->dev, "unable to get zynq-slcr regmap"); > + return PTR_ERR(priv->slcr); > + } > + > + priv->rcdev.owner = THIS_MODULE; > + priv->rcdev.nr_resets = NBANKS * BITS_PER_LONG; > + priv->rcdev.ops = &zynq_reset_ops; > + priv->rcdev.of_node = pdev->dev.of_node; > + reset_controller_register(&priv->rcdev); > + > + return 0; > +} > + > +static int zynq_reset_remove(struct platform_device *pdev) > +{ > + struct zynq_reset_data *priv = platform_get_drvdata(pdev); > + > + reset_controller_unregister(&priv->rcdev); > + > + return 0; > +} > + > +static const struct of_device_id zynq_reset_dt_ids[] = { > + { .compatible = "xlnx,zynq-reset", }, > + { /* sentinel */ }, > +}; > + > +static struct platform_driver zynq_reset_driver = { > + .probe = zynq_reset_probe, > + .remove = zynq_reset_remove, > + .driver = { > + .name = "zynq-pl-reset", PL in name. BTW: Don't you want to use KBUILD_MODNAME here? > + .of_match_table = zynq_reset_dt_ids, > + }, > +}; > +module_platform_driver(zynq_reset_driver); > + > +MODULE_LICENSE("GPL v2"); > +MODULE_AUTHOR("Moritz Fischer <moritz.fischer@ettus.com>"); > +MODULE_DESCRIPTION("Zynq Reset Controller Driver"); > The rest looks good - will test it. Thanks, Michal
Hi Moritz, Am Freitag, den 24.07.2015, 17:21 -0700 schrieb Moritz Fischer: > This adds a reset controller driver to control the Xilinx Zynq > SoC's various resets. > > Signed-off-by: Moritz Fischer <moritz.fischer@ettus.com> > --- > drivers/reset/Makefile | 1 + > drivers/reset/reset-zynq.c | 142 +++++++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 143 insertions(+) > create mode 100644 drivers/reset/reset-zynq.c > > diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile > index 157d421..3fe50e7 100644 > --- a/drivers/reset/Makefile > +++ b/drivers/reset/Makefile > @@ -3,3 +3,4 @@ obj-$(CONFIG_ARCH_SOCFPGA) += reset-socfpga.o > obj-$(CONFIG_ARCH_BERLIN) += reset-berlin.o > obj-$(CONFIG_ARCH_SUNXI) += reset-sunxi.o > obj-$(CONFIG_ARCH_STI) += sti/ > +obj-$(CONFIG_ARCH_ZYNQ) += reset-zynq.o > diff --git a/drivers/reset/reset-zynq.c b/drivers/reset/reset-zynq.c > new file mode 100644 > index 0000000..05e37f8 > --- /dev/null > +++ b/drivers/reset/reset-zynq.c > @@ -0,0 +1,142 @@ > +/* > + * Copyright (c) 2015, National Instruments Corp. > + * > + * Xilinx Zynq Reset controller driver > + * > + * 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; version 2 of the License. > + * > + * 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. > + */ > + > +#include <linux/err.h> > +#include <linux/io.h> > +#include <linux/module.h> > +#include <linux/mfd/syscon.h> > +#include <linux/of.h> > +#include <linux/platform_device.h> > +#include <linux/reset-controller.h> > +#include <linux/regmap.h> > +#include <linux/types.h> > + > +/* Offsets into SLCR regmap */ > +#define SLCR_RST_CTRL_OFFSET 0x200 /* FPGA Software Reset Control */ Maybe get this value from the reg property? I'm not sure if this is ever expected to change. > +#define NBANKS 18 reg = <0x200 0x50> says there are two more registers, are those not used? > +struct zynq_reset_data { > + struct regmap *slcr; > + struct reset_controller_dev rcdev; > +}; > + > +#define to_zynq_reset_data(p) \ > + container_of((p), struct zynq_reset_data, rcdev) > + > +static int zynq_reset_assert(struct reset_controller_dev *rcdev, > + unsigned long id) > +{ > + struct zynq_reset_data *priv = to_zynq_reset_data(rcdev); > + > + int bank = id / BITS_PER_LONG; > + int offset = id % BITS_PER_LONG; > + > + regmap_update_bits(priv->slcr, > + SLCR_RST_CTRL_OFFSET + (bank * 4), > + BIT(offset), > + BIT(offset)); > + > + return 0; > +} Just "return regmap_update_bits(...)" here ... > +static int zynq_reset_deassert(struct reset_controller_dev *rcdev, > + unsigned long id) > +{ > + struct zynq_reset_data *priv = to_zynq_reset_data(rcdev); > + > + int bank = id / BITS_PER_LONG; > + int offset = id % BITS_PER_LONG; > + > + regmap_update_bits(priv->slcr, > + SLCR_RST_CTRL_OFFSET + (bank * 4), > + BIT(offset), > + ~BIT(offset)); > + > + return 0; > +} ... and here. > +static int zynq_reset_status(struct reset_controller_dev *rcdev, > + unsigned long id) > +{ > + struct zynq_reset_data *priv = to_zynq_reset_data(rcdev); > + > + int bank = id / BITS_PER_LONG; > + int offset = id % BITS_PER_LONG; > + u32 reg; > + > + regmap_read(priv->slcr, SLCR_RST_CTRL_OFFSET + (bank * 4), ®); > + > + return !(reg & BIT(offset)); > +} Do I understand this correctly, you write 1 to assert the reset, but the register reads 0 while the reset is asserted and 1 otherwise? Also note that reset_status may return negative ERRNO, so for offset == 31 you should not return (1<<31). > +static const struct reset_control_ops zynq_reset_ops = { > + .assert = zynq_reset_assert, > + .deassert = zynq_reset_deassert, > + .status = zynq_reset_status, > +}; > + > +static int zynq_reset_probe(struct platform_device *pdev) > +{ > + struct zynq_reset_data *priv; > + > + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); > + if (!priv) > + return -ENOMEM; > + platform_set_drvdata(pdev, priv); > + > + priv->slcr = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, > + "syscon"); I'd just use syscon_node_to_regmap(pdev->dev.of_node->parent) here, which removes the need for the syscon phandle binding. > + if (IS_ERR(priv->slcr)) { > + dev_err(&pdev->dev, "unable to get zynq-slcr regmap"); > + return PTR_ERR(priv->slcr); > + } > + > + priv->rcdev.owner = THIS_MODULE; > + priv->rcdev.nr_resets = NBANKS * BITS_PER_LONG; > + priv->rcdev.ops = &zynq_reset_ops; > + priv->rcdev.of_node = pdev->dev.of_node; > + reset_controller_register(&priv->rcdev); > + > + return 0; > +} > + > +static int zynq_reset_remove(struct platform_device *pdev) > +{ > + struct zynq_reset_data *priv = platform_get_drvdata(pdev); > + > + reset_controller_unregister(&priv->rcdev); > + > + return 0; > +} > + > +static const struct of_device_id zynq_reset_dt_ids[] = { > + { .compatible = "xlnx,zynq-reset", }, > + { /* sentinel */ }, > +}; > + > +static struct platform_driver zynq_reset_driver = { > + .probe = zynq_reset_probe, > + .remove = zynq_reset_remove, > + .driver = { > + .name = "zynq-pl-reset", Is -pl- a leftover? > + .of_match_table = zynq_reset_dt_ids, > + }, > +}; > +module_platform_driver(zynq_reset_driver); > + > +MODULE_LICENSE("GPL v2"); > +MODULE_AUTHOR("Moritz Fischer <moritz.fischer@ettus.com>"); > +MODULE_DESCRIPTION("Zynq Reset Controller Driver"); regards Philipp
Philip, thanks for your review :) On Tue, Jul 28, 2015 at 1:38 AM, Philipp Zabel <p.zabel@pengutronix.de> wrote: > Hi Moritz, > > Am Freitag, den 24.07.2015, 17:21 -0700 schrieb Moritz Fischer: >> This adds a reset controller driver to control the Xilinx Zynq >> SoC's various resets. >> >> Signed-off-by: Moritz Fischer <moritz.fischer@ettus.com> >> --- >> drivers/reset/Makefile | 1 + >> drivers/reset/reset-zynq.c | 142 +++++++++++++++++++++++++++++++++++++++++++++ >> 2 files changed, 143 insertions(+) >> create mode 100644 drivers/reset/reset-zynq.c >> >> diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile >> index 157d421..3fe50e7 100644 >> --- a/drivers/reset/Makefile >> +++ b/drivers/reset/Makefile >> @@ -3,3 +3,4 @@ obj-$(CONFIG_ARCH_SOCFPGA) += reset-socfpga.o >> obj-$(CONFIG_ARCH_BERLIN) += reset-berlin.o >> obj-$(CONFIG_ARCH_SUNXI) += reset-sunxi.o >> obj-$(CONFIG_ARCH_STI) += sti/ >> +obj-$(CONFIG_ARCH_ZYNQ) += reset-zynq.o >> diff --git a/drivers/reset/reset-zynq.c b/drivers/reset/reset-zynq.c >> new file mode 100644 >> index 0000000..05e37f8 >> --- /dev/null >> +++ b/drivers/reset/reset-zynq.c >> @@ -0,0 +1,142 @@ >> +/* >> + * Copyright (c) 2015, National Instruments Corp. >> + * >> + * Xilinx Zynq Reset controller driver >> + * >> + * 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; version 2 of the License. >> + * >> + * 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. >> + */ >> + >> +#include <linux/err.h> >> +#include <linux/io.h> >> +#include <linux/module.h> >> +#include <linux/mfd/syscon.h> >> +#include <linux/of.h> >> +#include <linux/platform_device.h> >> +#include <linux/reset-controller.h> >> +#include <linux/regmap.h> >> +#include <linux/types.h> >> + >> +/* Offsets into SLCR regmap */ >> +#define SLCR_RST_CTRL_OFFSET 0x200 /* FPGA Software Reset Control */ > > Maybe get this value from the reg property? I'm not sure if this is ever > expected to change. I don't think it's going to change. Is there a reason to only expose part of the resets? > >> +#define NBANKS 18 > > reg = <0x200 0x50> says there are two more registers, are those not used? Should be 0x48, you're right. Michal had suggested 0x50, but the last two regs are not really resets. > >> +struct zynq_reset_data { >> + struct regmap *slcr; >> + struct reset_controller_dev rcdev; >> +}; >> + >> +#define to_zynq_reset_data(p) \ >> + container_of((p), struct zynq_reset_data, rcdev) >> + >> +static int zynq_reset_assert(struct reset_controller_dev *rcdev, >> + unsigned long id) >> +{ >> + struct zynq_reset_data *priv = to_zynq_reset_data(rcdev); >> + >> + int bank = id / BITS_PER_LONG; >> + int offset = id % BITS_PER_LONG; >> + >> + regmap_update_bits(priv->slcr, >> + SLCR_RST_CTRL_OFFSET + (bank * 4), >> + BIT(offset), >> + BIT(offset)); >> + >> + return 0; >> +} > > Just "return regmap_update_bits(...)" here ... Yup, good point. > >> +static int zynq_reset_deassert(struct reset_controller_dev *rcdev, >> + unsigned long id) >> +{ >> + struct zynq_reset_data *priv = to_zynq_reset_data(rcdev); >> + >> + int bank = id / BITS_PER_LONG; >> + int offset = id % BITS_PER_LONG; >> + >> + regmap_update_bits(priv->slcr, >> + SLCR_RST_CTRL_OFFSET + (bank * 4), >> + BIT(offset), >> + ~BIT(offset)); >> + >> + return 0; >> +} > > ... and here. > >> +static int zynq_reset_status(struct reset_controller_dev *rcdev, >> + unsigned long id) >> +{ >> + struct zynq_reset_data *priv = to_zynq_reset_data(rcdev); >> + >> + int bank = id / BITS_PER_LONG; >> + int offset = id % BITS_PER_LONG; >> + u32 reg; >> + >> + regmap_read(priv->slcr, SLCR_RST_CTRL_OFFSET + (bank * 4), ®); >> + >> + return !(reg & BIT(offset)); >> +} Will change to: ret = regmap_read(priv->slcr, SLCR_RST_CTRL_OFFSET + (bank * 4), ®); if (ret) return ret; else return !!(reg & BIT(offset)); the single '!' was a typo ... > > Do I understand this correctly, you write 1 to assert the reset, but the > register reads 0 while the reset is asserted and 1 otherwise? > Also note that reset_status may return negative ERRNO, so for offset == > 31 you should not return (1<<31). > >> +static const struct reset_control_ops zynq_reset_ops = { >> + .assert = zynq_reset_assert, >> + .deassert = zynq_reset_deassert, >> + .status = zynq_reset_status, >> +}; >> + >> +static int zynq_reset_probe(struct platform_device *pdev) >> +{ >> + struct zynq_reset_data *priv; >> + >> + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); >> + if (!priv) >> + return -ENOMEM; >> + platform_set_drvdata(pdev, priv); >> + >> + priv->slcr = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, >> + "syscon"); > > I'd just use syscon_node_to_regmap(pdev->dev.of_node->parent) here, > which removes the need for the syscon phandle binding. See binding doc discussion. I don't have a strong preference either way, just tried to be consistent with the pinctrl node. We just need a decision one way or the other :) > >> + if (IS_ERR(priv->slcr)) { >> + dev_err(&pdev->dev, "unable to get zynq-slcr regmap"); >> + return PTR_ERR(priv->slcr); >> + } >> + >> + priv->rcdev.owner = THIS_MODULE; >> + priv->rcdev.nr_resets = NBANKS * BITS_PER_LONG; >> + priv->rcdev.ops = &zynq_reset_ops; >> + priv->rcdev.of_node = pdev->dev.of_node; >> + reset_controller_register(&priv->rcdev); >> + >> + return 0; >> +} >> + >> +static int zynq_reset_remove(struct platform_device *pdev) >> +{ >> + struct zynq_reset_data *priv = platform_get_drvdata(pdev); >> + >> + reset_controller_unregister(&priv->rcdev); >> + >> + return 0; >> +} >> + >> +static const struct of_device_id zynq_reset_dt_ids[] = { >> + { .compatible = "xlnx,zynq-reset", }, >> + { /* sentinel */ }, >> +}; >> + >> +static struct platform_driver zynq_reset_driver = { >> + .probe = zynq_reset_probe, >> + .remove = zynq_reset_remove, >> + .driver = { >> + .name = "zynq-pl-reset", > > Is -pl- a leftover? Yes ... will fix that. > >> + .of_match_table = zynq_reset_dt_ids, >> + }, >> +}; >> +module_platform_driver(zynq_reset_driver); >> + >> +MODULE_LICENSE("GPL v2"); >> +MODULE_AUTHOR("Moritz Fischer <moritz.fischer@ettus.com>"); >> +MODULE_DESCRIPTION("Zynq Reset Controller Driver"); > > regards > Philipp > Thanks, Moritz
On Tue, 2015-07-28 at 07:05AM -0700, Moritz Fischer wrote: > Philip, > > thanks for your review :) > > On Tue, Jul 28, 2015 at 1:38 AM, Philipp Zabel <p.zabel@pengutronix.de> wrote: > > Hi Moritz, > > > > Am Freitag, den 24.07.2015, 17:21 -0700 schrieb Moritz Fischer: > >> This adds a reset controller driver to control the Xilinx Zynq > >> SoC's various resets. > >> > >> Signed-off-by: Moritz Fischer <moritz.fischer@ettus.com> [...] > >> + > >> +/* Offsets into SLCR regmap */ > >> +#define SLCR_RST_CTRL_OFFSET 0x200 /* FPGA Software Reset Control */ > > > > Maybe get this value from the reg property? I'm not sure if this is ever > > expected to change. > I don't think it's going to change. Is there a reason to only expose > part of the resets? I think all other users of the syscon (in the Zynq DT) use the 'reg' property to retrieve an offset into the SLCR. We should probably do that here too and remove the #define. Who knows, maybe this driver is reusable with some modifications for the Zynq MPSoC. > > > >> +#define NBANKS 18 > > > > reg = <0x200 0x50> says there are two more registers, are those not used? > > Should be 0x48, you're right. Michal had suggested 0x50, but the last > two regs are not really resets. > > [...] > >> +static int zynq_reset_status(struct reset_controller_dev *rcdev, > >> + unsigned long id) > >> +{ > >> + struct zynq_reset_data *priv = to_zynq_reset_data(rcdev); > >> + > >> + int bank = id / BITS_PER_LONG; > >> + int offset = id % BITS_PER_LONG; > >> + u32 reg; > >> + > >> + regmap_read(priv->slcr, SLCR_RST_CTRL_OFFSET + (bank * 4), ®); > >> + > >> + return !(reg & BIT(offset)); > >> +} > > Will change to: > ret = regmap_read(priv->slcr, SLCR_RST_CTRL_OFFSET + (bank * 4), ®); > if (ret) > return ret; > else > return !!(reg & BIT(offset)); > > the single '!' was a typo ... You have an early return on error in the if-branch. No need for the else. > > > > > Do I understand this correctly, you write 1 to assert the reset, but the > > register reads 0 while the reset is asserted and 1 otherwise? > > Also note that reset_status may return negative ERRNO, so for offset == > > 31 you should not return (1<<31). > > > >> +static const struct reset_control_ops zynq_reset_ops = { > >> + .assert = zynq_reset_assert, > >> + .deassert = zynq_reset_deassert, > >> + .status = zynq_reset_status, > >> +}; > >> + > >> +static int zynq_reset_probe(struct platform_device *pdev) > >> +{ > >> + struct zynq_reset_data *priv; > >> + > >> + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); > >> + if (!priv) > >> + return -ENOMEM; > >> + platform_set_drvdata(pdev, priv); > >> + > >> + priv->slcr = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, > >> + "syscon"); > > > > I'd just use syscon_node_to_regmap(pdev->dev.of_node->parent) here, > > which removes the need for the syscon phandle binding. > > See binding doc discussion. I don't have a strong preference either way, > just tried to be consistent with the pinctrl node. > We just need a decision one way or the other :) I personally like the syscon handle better since it would make placing the node more flexible, while this proposal forces some topology on the DT. In both cases though, the syscon and this user are tightly coupled and this driver depends on the syscon. I don't really mind either way - I think. Sören
diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile index 157d421..3fe50e7 100644 --- a/drivers/reset/Makefile +++ b/drivers/reset/Makefile @@ -3,3 +3,4 @@ obj-$(CONFIG_ARCH_SOCFPGA) += reset-socfpga.o obj-$(CONFIG_ARCH_BERLIN) += reset-berlin.o obj-$(CONFIG_ARCH_SUNXI) += reset-sunxi.o obj-$(CONFIG_ARCH_STI) += sti/ +obj-$(CONFIG_ARCH_ZYNQ) += reset-zynq.o diff --git a/drivers/reset/reset-zynq.c b/drivers/reset/reset-zynq.c new file mode 100644 index 0000000..05e37f8 --- /dev/null +++ b/drivers/reset/reset-zynq.c @@ -0,0 +1,142 @@ +/* + * Copyright (c) 2015, National Instruments Corp. + * + * Xilinx Zynq Reset controller driver + * + * 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; version 2 of the License. + * + * 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. + */ + +#include <linux/err.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/mfd/syscon.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/reset-controller.h> +#include <linux/regmap.h> +#include <linux/types.h> + +/* Offsets into SLCR regmap */ +#define SLCR_RST_CTRL_OFFSET 0x200 /* FPGA Software Reset Control */ + +#define NBANKS 18 + +struct zynq_reset_data { + struct regmap *slcr; + struct reset_controller_dev rcdev; +}; + +#define to_zynq_reset_data(p) \ + container_of((p), struct zynq_reset_data, rcdev) + +static int zynq_reset_assert(struct reset_controller_dev *rcdev, + unsigned long id) +{ + struct zynq_reset_data *priv = to_zynq_reset_data(rcdev); + + int bank = id / BITS_PER_LONG; + int offset = id % BITS_PER_LONG; + + regmap_update_bits(priv->slcr, + SLCR_RST_CTRL_OFFSET + (bank * 4), + BIT(offset), + BIT(offset)); + + return 0; +} + +static int zynq_reset_deassert(struct reset_controller_dev *rcdev, + unsigned long id) +{ + struct zynq_reset_data *priv = to_zynq_reset_data(rcdev); + + int bank = id / BITS_PER_LONG; + int offset = id % BITS_PER_LONG; + + regmap_update_bits(priv->slcr, + SLCR_RST_CTRL_OFFSET + (bank * 4), + BIT(offset), + ~BIT(offset)); + + return 0; +} + +static int zynq_reset_status(struct reset_controller_dev *rcdev, + unsigned long id) +{ + struct zynq_reset_data *priv = to_zynq_reset_data(rcdev); + + int bank = id / BITS_PER_LONG; + int offset = id % BITS_PER_LONG; + u32 reg; + + regmap_read(priv->slcr, SLCR_RST_CTRL_OFFSET + (bank * 4), ®); + + return !(reg & BIT(offset)); +} + +static const struct reset_control_ops zynq_reset_ops = { + .assert = zynq_reset_assert, + .deassert = zynq_reset_deassert, + .status = zynq_reset_status, +}; + +static int zynq_reset_probe(struct platform_device *pdev) +{ + struct zynq_reset_data *priv; + + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + platform_set_drvdata(pdev, priv); + + priv->slcr = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, + "syscon"); + if (IS_ERR(priv->slcr)) { + dev_err(&pdev->dev, "unable to get zynq-slcr regmap"); + return PTR_ERR(priv->slcr); + } + + priv->rcdev.owner = THIS_MODULE; + priv->rcdev.nr_resets = NBANKS * BITS_PER_LONG; + priv->rcdev.ops = &zynq_reset_ops; + priv->rcdev.of_node = pdev->dev.of_node; + reset_controller_register(&priv->rcdev); + + return 0; +} + +static int zynq_reset_remove(struct platform_device *pdev) +{ + struct zynq_reset_data *priv = platform_get_drvdata(pdev); + + reset_controller_unregister(&priv->rcdev); + + return 0; +} + +static const struct of_device_id zynq_reset_dt_ids[] = { + { .compatible = "xlnx,zynq-reset", }, + { /* sentinel */ }, +}; + +static struct platform_driver zynq_reset_driver = { + .probe = zynq_reset_probe, + .remove = zynq_reset_remove, + .driver = { + .name = "zynq-pl-reset", + .of_match_table = zynq_reset_dt_ids, + }, +}; +module_platform_driver(zynq_reset_driver); + +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("Moritz Fischer <moritz.fischer@ettus.com>"); +MODULE_DESCRIPTION("Zynq Reset Controller Driver");
This adds a reset controller driver to control the Xilinx Zynq SoC's various resets. Signed-off-by: Moritz Fischer <moritz.fischer@ettus.com> --- drivers/reset/Makefile | 1 + drivers/reset/reset-zynq.c | 142 +++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 143 insertions(+) create mode 100644 drivers/reset/reset-zynq.c