From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933107AbcFBSB5 (ORCPT ); Thu, 2 Jun 2016 14:01:57 -0400 Received: from mail-wm0-f51.google.com ([74.125.82.51]:37098 "EHLO mail-wm0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752514AbcFBSBz convert rfc822-to-8bit (ORCPT ); Thu, 2 Jun 2016 14:01:55 -0400 Subject: Re: [PATCH/RFC 1/1] soc: renesas: Add DT fixup code for missing r8a7791 RST Mime-Version: 1.0 (Mac OS X Mail 9.3 \(3124\)) Content-Type: text/plain; charset=utf-8 From: Pantelis Antoniou In-Reply-To: <1464810650-23002-2-git-send-email-geert+renesas@glider.be> Date: Thu, 2 Jun 2016 21:01:50 +0300 Cc: Simon Horman , Magnus Damm , Laurent Pinchart , Dirk Behme , Rob Herring , Frank Rowand , Grant Likely , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , Arnd Bergmann , Thomas Petazzoni , linux-renesas-soc@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8BIT Message-Id: References: <1464810650-23002-1-git-send-email-geert+renesas@glider.be> <1464810650-23002-2-git-send-email-geert+renesas@glider.be> To: Geert Uytterhoeven X-Mailer: Apple Mail (2.3124) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Geert, A few notes. > On Jun 1, 2016, at 22:50 , Geert Uytterhoeven wrote: > > Add DT fixup code to add a reset-controller node for the r8a7791 RST > module if it's not yet present. > > This allows the R-Car Gen2 clock driver to use the RST driver to obtain > the value of the mode pins, instead of reading from a hardcoded address > in rcar_gen2_read_mode_pins(), while providing backward compatibility > with old DTBs. > > Signed-off-by: Geert Uytterhoeven > --- > --- > drivers/soc/renesas/Makefile | 4 + > drivers/soc/renesas/renesas-dt-fixup.c | 159 +++++++++++++++++++++++++++++++++ > 2 files changed, 163 insertions(+) > create mode 100644 drivers/soc/renesas/renesas-dt-fixup.c > > diff --git a/drivers/soc/renesas/Makefile b/drivers/soc/renesas/Makefile > index 0d732ff893dd8fba..e5f4454821ca6f63 100644 > --- a/drivers/soc/renesas/Makefile > +++ b/drivers/soc/renesas/Makefile > @@ -1,3 +1,7 @@ > +# FIXME Depend on new Kconfig symbol CONFIG_ARCH_RENESAS_LEGACY > +# FIXME Needs OF_DYNAMIC > +obj-$(CONFIG_ARCH_RENESAS) += renesas-dt-fixup.o > + > obj-$(CONFIG_ARCH_RCAR_GEN1) += rcar-rst.o > obj-$(CONFIG_ARCH_RCAR_GEN2) += rcar-rst.o > obj-$(CONFIG_ARCH_R8A7795) += rcar-rst.o > diff --git a/drivers/soc/renesas/renesas-dt-fixup.c b/drivers/soc/renesas/renesas-dt-fixup.c > new file mode 100644 > index 0000000000000000..83c9ca6b44f8136c > --- /dev/null > +++ b/drivers/soc/renesas/renesas-dt-fixup.c > @@ -0,0 +1,159 @@ > +/* > + * Renesas DT Fixup Code > + * > + * Provide backwards compatibility with old DTBs by updating the DT > + * > + * Copyright (C) 2016 Glider bvba > + * > + * This file is subject to the terms and conditions of the GNU General Public > + * License. See the file "COPYING" in the main directory of this archive > + * for more details. > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > + > +#define RST_BASE 0xe6160000 > +#define RST_SIZE 0x0100 /* R-Car Gen2 */ > + > +static struct property rst_compatible = { > + .name = "compatible", > +}; > + > +static __be32 rst_reg_values[4] = { > + cpu_to_be32(0), > + cpu_to_be32(RST_BASE), > + cpu_to_be32(0), > + cpu_to_be32(RST_SIZE), > +}; > + > +static struct property rst_name = { > + .name = "name", > + .length = sizeof("reset-controller"), > + .value = "reset-controller", > +}; > + > +static struct property rst_reg = { > + .name = "reg", > + .length = sizeof(rst_reg_values), > + .value = rst_reg_values, > +}; > + > +static int __init add_rst(struct device_node *parent, const char *path, > + char *compatible) > +{ > + struct property *prop[] = { &rst_compatible, &rst_name, &rst_reg }; > + struct device_node *np; > + char *full_name; > + unsigned int i; > + int error; > + > + pr_debug("Adding RST node %s\n", compatible); > + np = kzalloc(sizeof(*np), GFP_KERNEL); > + if (!np) > + return -ENOMEM; > + > + np->name = kasprintf(GFP_KERNEL, "%s@%x", (char *)rst_name.value, > + RST_BASE); > + full_name = kasprintf(GFP_KERNEL, "%s/%s", path, np->name); > + np->full_name = full_name; > + np->parent = parent; > + > + of_node_set_flag(np, OF_DYNAMIC); > + of_node_init(np); > + > + error = of_attach_node(np); > + if (error) { > + pr_err("%s: of_attach_node() %s failed %d\n", __func__, > + np->name, error); > + kfree(np); > + return error; > + } > + > + rst_compatible.value = compatible; > + rst_compatible.length = strlen(rst_compatible.value) + 1; > + > + for (i = 0; i < ARRAY_SIZE(prop); i++) { > + error = of_add_property(np, prop[i]); > + if (error) > + pr_err("%s: of_add_property() %s/%s failed %d\n", > + __func__, np->name, prop[i]->name, error); > + } > + > + return 0; > +} > + Using changesets (especially with the new changeset helpers would make this so much simpler. Or you could compile in a DTBO that performs the changes although you will have to tweak it since it appears you’re not using fixed names and properties all the way. > +static int __init add_sysc(struct device_node *parent, const char *path, > + char *compatible) > +{ > + pr_debug("NOT YET adding SYSC node %s\n", compatible); > + return 0; > +} > + > +static const struct of_device_id renesas_matches[] __initconst = { > + { .compatible = "renesas,r8a7791", }, > + { /* sentinel */ } > +}; > + > +static int __init renesas_dt_fixup(void) > +{ > + const struct of_device_id *match; > + struct device_node *np, *parent; > + const char *parent_path; > + char *compatible; > + > + np = of_find_node_by_path("/"); > + if (!np) > + return -ENODEV; > + > + for (match = renesas_matches; match->compatible[0]; match++) > + if (of_device_is_compatible(np, match->compatible)) > + break; > + of_node_put(np); > + > + if (!match->compatible[0]) > + return -ENODEV; > + > + /* Find the main SoC bus node */ > + np = of_find_compatible_node(NULL, NULL, "arm,gic-400"); > + if (!np) { > + pr_warn("%s: Cannot find %s\n", __func__, "arm,gic-400"); > + return -ENODEV; > + } > + > + parent = of_get_parent(np); > + of_node_put(np); > + if (!parent) { > + pr_warn("%s: Cannot find GIC parent\n", __func__); > + return -ENODEV; > + } > + > + parent_path = parent->full_name; > + /* Prevent double leading slash */ > + if (!parent_path[1]) > + parent_path++; > + > + compatible = kasprintf(GFP_KERNEL, "%s-rst", match->compatible); > + if (of_find_compatible_node(NULL, NULL, compatible)) { > + pr_debug("%s: RST node %s present\n", __func__, compatible); > + kfree(compatible); > + } else { > + add_rst(parent, parent_path, compatible); > + } > + > + compatible = kasprintf(GFP_KERNEL, "%s-sysc", match->compatible); > + if (of_find_compatible_node(NULL, NULL, compatible)) { > + pr_debug("%s: SYSC node %s present\n", __func__, compatible); > + kfree(compatible); > + } else { > + add_sysc(parent, parent_path, compatible); > + } > + > + of_node_put(parent); > + return 0; > +} > +early_initcall(renesas_dt_fixup); > -- > 1.9.1 > Regards — Pantelis