Hi Peter, > -----Original Message----- > From: Peter Rosin [mailto:p...@axentia.se] > Sent: Monday, 18 February, 2019 03:17 PM > To: Pankaj Bansal <pankaj.ban...@nxp.com>; Leo Li <leoyang...@nxp.com>; > linux-kernel@vger.kernel.org; Philipp Zabel <p.za...@pengutronix.de> > Subject: Re: [PATCH] drivers: mux: Generic register bitfield-based multiplexer > driver > > Hi! > > On 2019-02-18 06:40, Pankaj Bansal wrote: > > Generic register bitfield-based multiplexer driver that controls the > > multiplexer producer defined under a parent node. > > The driver corresponding to parent node provides register read/write > > capabilities. > > This driver is just a rename of drivers/mux/mmio.c with a one-liner on top. > And > there's a license change too. That's obnoxious. Please keep this as GPL v2. > Not > that I /think/ Philipp nor Pengutronix cares deeply, but what do I know? > Changing the license as you copy the code is simply not all right.
My Apologies. I will fix it as I send V2. > > Anyway, I would prefer if you could extend drivers/mux/mmio.c to support both > compatibles, and using the compatible to select if > > regmap = syscon_node_to_regmap(np->parent); > > or > > regmap = dev_get_regmap(dev->parent, NULL); > > is called to get to the desired regmap. This can be done. The name mmio.c however suggests that mux is controlled by a Memory mapped device. IMO, if the generic regmap API is to be added to it, the name needs to changed. Any suggestions ? > > Philipp, you don't object to extending the mmio driver, right? > > Or are there more differences that I failed to notice? Nope, it's the only difference. > > Cheers, > Peter > > > > > Signed-off-by: Pankaj Bansal <pankaj.ban...@nxp.com> > > --- > > > > Notes: > > Dependencies: > > - > > https://emea01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fpat > > > chwork.ozlabs.org%2Fpatch%2F1043790%2F&data=02%7C01%7Cpankaj.b > ansa > > > l%40nxp.com%7C3b8a1e8520ce4345105108d695861210%7C686ea1d3bc2b4c6f > a92cd > > > 99c5c301635%7C0%7C0%7C636860800396857042&sdata=5e%2BhyasYwf > uc%2Fbr > > 1u6WKlKybYipz5c4ndBeLZDflHqk%3D&reserved=0 > > > > drivers/mux/Kconfig | 13 ++++ > > drivers/mux/Makefile | 2 + > > drivers/mux/regmap.c | 139 > +++++++++++++++++++++++++++++++++++++++++ > > 3 files changed, 154 insertions(+) > > > > diff --git a/drivers/mux/Kconfig b/drivers/mux/Kconfig index > > 7659d6c5f718..a412d0955258 100644 > > --- a/drivers/mux/Kconfig > > +++ b/drivers/mux/Kconfig > > @@ -58,4 +58,17 @@ config MUX_MMIO > > To compile the driver as a module, choose M here: the module will > > be called mux-mmio. > > > > +config MUX_REGMAP > > + tristate "Regmap register bitfield-controlled Multiplexer" > > + depends on (OF && REGMAP) || COMPILE_TEST > > + help > > + Regmap register bitfield-controlled Multiplexer controller. > > + > > + The driver builds multiplexer controllers for bitfields in a regmap > > + device register. For N bit wide bitfields, there will be 2^N possible > > + multiplexer states. > > + > > + To compile the driver as a module, choose M here: the module will > > + be called regmap-mmio. > > + > > endmenu > > diff --git a/drivers/mux/Makefile b/drivers/mux/Makefile index > > 6e9fa47daf56..ae1bafac0cbd 100644 > > --- a/drivers/mux/Makefile > > +++ b/drivers/mux/Makefile > > @@ -8,9 +8,11 @@ mux-adg792a-objs := adg792a.o > > mux-adgs1408-objs := adgs1408.o > > mux-gpio-objs := gpio.o > > mux-mmio-objs := mmio.o > > +mux-regmap-objs := regmap.o > > > > obj-$(CONFIG_MULTIPLEXER) += mux-core.o > > obj-$(CONFIG_MUX_ADG792A) += mux-adg792a.o > > obj-$(CONFIG_MUX_ADGS1408) += mux-adgs1408.o > > obj-$(CONFIG_MUX_GPIO) += mux-gpio.o > > obj-$(CONFIG_MUX_MMIO) += mux-mmio.o > > +obj-$(CONFIG_MUX_REGMAP) += mux-regmap.o > > diff --git a/drivers/mux/regmap.c b/drivers/mux/regmap.c new file mode > > 100644 index 000000000000..c2156302929a > > --- /dev/null > > +++ b/drivers/mux/regmap.c > > @@ -0,0 +1,139 @@ > > +// SPDX-License-Identifier: GPL-2.0+ > > +/* > > + * Regmap register bitfield-controlled multiplexer driver > > + * > > + * Based on drivers/mux/mmio.c > > + * > > + * Copyright 2019 NXP > > + */ > > + > > +#include <linux/bitops.h> > > +#include <linux/err.h> > > +#include <linux/module.h> > > +#include <linux/mux/driver.h> > > +#include <linux/of_platform.h> > > +#include <linux/platform_device.h> > > +#include <linux/property.h> > > +#include <linux/regmap.h> > > + > > +static int mux_regmap_set(struct mux_control *mux, int state) { > > + struct regmap_field **fields = mux_chip_priv(mux->chip); > > + > > + return regmap_field_write(fields[mux_control_get_index(mux)], > > +state); } > > + > > +static const struct mux_control_ops mux_regmap_ops = { > > + .set = mux_regmap_set, > > +}; > > + > > +static const struct of_device_id mux_regmap_dt_ids[] = { > > + { .compatible = "reg-mux", }, > > + { /* sentinel */ } > > +}; > > +MODULE_DEVICE_TABLE(of, mux_regmap_dt_ids); > > + > > +static int mux_regmap_probe(struct platform_device *pdev) { > > + struct device *dev = &pdev->dev; > > + struct device_node *np = dev->of_node; > > + struct regmap_field **fields; > > + struct mux_chip *mux_chip; > > + struct regmap *regmap; > > + int num_fields; > > + int ret; > > + int i; > > + > > + regmap = dev_get_regmap(dev->parent, NULL); > > + if (IS_ERR(regmap)) { > > + ret = PTR_ERR(regmap); > > + dev_err(dev, "failed to get regmap: %d\n", ret); > > + return ret; > > + } > > + > > + ret = of_property_count_u32_elems(np, "mux-reg-masks"); > > + if (ret == 0 || ret % 2) > > + ret = -EINVAL; > > + if (ret < 0) { > > + dev_err(dev, "mux-reg-masks property missing or invalid: %d\n", > > + ret); > > + return ret; > > + } > > + num_fields = ret / 2; > > + > > + mux_chip = devm_mux_chip_alloc(dev, num_fields, num_fields * > > + sizeof(*fields)); > > + if (IS_ERR(mux_chip)) > > + return PTR_ERR(mux_chip); > > + > > + fields = mux_chip_priv(mux_chip); > > + > > + for (i = 0; i < num_fields; i++) { > > + struct mux_control *mux = &mux_chip->mux[i]; > > + struct reg_field field; > > + s32 idle_state = MUX_IDLE_AS_IS; > > + u32 reg, mask; > > + int bits; > > + > > + ret = of_property_read_u32_index(np, "mux-reg-masks", > > + 2 * i, ®); > > + if (!ret) > > + ret = of_property_read_u32_index(np, "mux-reg- > masks", > > + 2 * i + 1, &mask); > > + if (ret < 0) { > > + dev_err(dev, "bitfield %d: failed to read mux-reg-masks > property: %d\n", > > + i, ret); > > + return ret; > > + } > > + > > + field.reg = reg; > > + field.msb = fls(mask) - 1; > > + field.lsb = ffs(mask) - 1; > > + > > + if (mask != GENMASK(field.msb, field.lsb)) { > > + dev_err(dev, "bitfield %d: invalid mask 0x%x\n", > > + i, mask); > > + return -EINVAL; > > + } > > + > > + fields[i] = devm_regmap_field_alloc(dev, regmap, field); > > + if (IS_ERR(fields[i])) { > > + ret = PTR_ERR(fields[i]); > > + dev_err(dev, "bitfield %d: failed allocate: %d\n", > > + i, ret); > > + return ret; > > + } > > + > > + bits = 1 + field.msb - field.lsb; > > + mux->states = 1 << bits; > > + > > + of_property_read_u32_index(np, "idle-states", i, > > + (u32 *)&idle_state); > > + if (idle_state != MUX_IDLE_AS_IS) { > > + if (idle_state < 0 || idle_state >= mux->states) { > > + dev_err(dev, "bitfield: %d: out of range idle > state %d\n", > > + i, idle_state); > > + return -EINVAL; > > + } > > + > > + mux->idle_state = idle_state; > > + } > > + } > > + > > + mux_chip->ops = &mux_regmap_ops; > > + > > + return devm_mux_chip_register(dev, mux_chip); } > > + > > +static struct platform_driver mux_regmap_driver = { > > + .driver = { > > + .name = "regmap-mux", > > + .of_match_table = of_match_ptr(mux_regmap_dt_ids), > > + }, > > + .probe = mux_regmap_probe, > > +}; > > +module_platform_driver(mux_regmap_driver); > > + > > +MODULE_DESCRIPTION("Regmap register bitfield-controlled multiplexer > > +driver"); MODULE_AUTHOR("Pankaj Bansal <pankaj.ban...@nxp.com>"); > > +MODULE_LICENSE("GPL"); > >
