From: Damien Riegel <damien.riegel@savoirfairelinux.com> To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-watchdog@vger.kernel.org Cc: Lee Jones <lee.jones@linaro.org>, robh+dt@kernel.org, shawnguo@kernel.org, kernel@pengutronix.de, wim@iguana.be, sameo@linux.intel.com, dinh.linux@gmail.com, linux@roeck-us.net, Arnd Bergmann <arnd@arndb.de>, kernel@savoirfairelinux.com, Damien Riegel <damien.riegel@savoirfairelinux.com> Subject: [PATCH v5 2/5] mfd: syscon: add a DT property to set value width Date: Tue, 24 Nov 2015 13:00:50 -0500 [thread overview] Message-ID: <1448388053-30661-3-git-send-email-damien.riegel@savoirfairelinux.com> (raw) In-Reply-To: <1448388053-30661-1-git-send-email-damien.riegel@savoirfairelinux.com> Currently syscon has a fixed configuration of 32 bits for register and values widths. In some cases, it would be desirable to be able to customize the value width. For example, certain boards (like the ones manufactured by Technologic Systems) have a FPGA that is memory-mapped, but its registers are only 16-bit wide. This patch adds an optional "bus-width" DT binding for syscon that allows to change the width for the data bus (i.e. val_bits). If this property is provided, it will also adjust the register stride to bus-width / 8. If not provided, the default configuration is used. Signed-off-by: Damien Riegel <damien.riegel@savoirfairelinux.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Lee Jones <lee.jones@linaro.org> --- Documentation/devicetree/bindings/mfd/syscon.txt | 3 +++ drivers/mfd/syscon.c | 13 +++++++++++++ 2 files changed, 16 insertions(+) diff --git a/Documentation/devicetree/bindings/mfd/syscon.txt b/Documentation/devicetree/bindings/mfd/syscon.txt index fe8150b..4c9d187 100644 --- a/Documentation/devicetree/bindings/mfd/syscon.txt +++ b/Documentation/devicetree/bindings/mfd/syscon.txt @@ -13,6 +13,9 @@ Required properties: - compatible: Should contain "syscon". - reg: the register region can be accessed from syscon +Optional property: +- bus-width: width of the data bus. Can be <8>, <16>, <32>, or <64>. + Examples: gpr: iomuxc-gpr@020e0000 { compatible = "fsl,imx6q-iomuxc-gpr", "syscon"; diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c index 176bf0f..5a93d80 100644 --- a/drivers/mfd/syscon.c +++ b/drivers/mfd/syscon.c @@ -47,6 +47,7 @@ static struct syscon *of_syscon_register(struct device_node *np) struct syscon *syscon; struct regmap *regmap; void __iomem *base; + u32 bus_width; int ret; struct regmap_config syscon_config = syscon_regmap_config; @@ -69,6 +70,18 @@ static struct syscon *of_syscon_register(struct device_node *np) else if (of_property_read_bool(np, "little-endian")) syscon_config.val_format_endian = REGMAP_ENDIAN_LITTLE; + /* + * search for bus-width property in DT. If it is not provided, default + * to 32-bit. regmap_init_mmio will return an error if syscon_config's + * values are invalid so there is no need to check them here. + */ + ret = of_property_read_u32(np, "bus-width", &bus_width); + if (ret) + bus_width = 32; + + syscon_config.val_bits = bus_width; + syscon_config.reg_stride = syscon_config.val_bits / 8; + regmap = regmap_init_mmio(NULL, base, &syscon_config); if (IS_ERR(regmap)) { pr_err("regmap init failed\n"); -- 2.5.0
WARNING: multiple messages have this Message-ID (diff)
From: damien.riegel@savoirfairelinux.com (Damien Riegel) To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v5 2/5] mfd: syscon: add a DT property to set value width Date: Tue, 24 Nov 2015 13:00:50 -0500 [thread overview] Message-ID: <1448388053-30661-3-git-send-email-damien.riegel@savoirfairelinux.com> (raw) In-Reply-To: <1448388053-30661-1-git-send-email-damien.riegel@savoirfairelinux.com> Currently syscon has a fixed configuration of 32 bits for register and values widths. In some cases, it would be desirable to be able to customize the value width. For example, certain boards (like the ones manufactured by Technologic Systems) have a FPGA that is memory-mapped, but its registers are only 16-bit wide. This patch adds an optional "bus-width" DT binding for syscon that allows to change the width for the data bus (i.e. val_bits). If this property is provided, it will also adjust the register stride to bus-width / 8. If not provided, the default configuration is used. Signed-off-by: Damien Riegel <damien.riegel@savoirfairelinux.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Lee Jones <lee.jones@linaro.org> --- Documentation/devicetree/bindings/mfd/syscon.txt | 3 +++ drivers/mfd/syscon.c | 13 +++++++++++++ 2 files changed, 16 insertions(+) diff --git a/Documentation/devicetree/bindings/mfd/syscon.txt b/Documentation/devicetree/bindings/mfd/syscon.txt index fe8150b..4c9d187 100644 --- a/Documentation/devicetree/bindings/mfd/syscon.txt +++ b/Documentation/devicetree/bindings/mfd/syscon.txt @@ -13,6 +13,9 @@ Required properties: - compatible: Should contain "syscon". - reg: the register region can be accessed from syscon +Optional property: +- bus-width: width of the data bus. Can be <8>, <16>, <32>, or <64>. + Examples: gpr: iomuxc-gpr at 020e0000 { compatible = "fsl,imx6q-iomuxc-gpr", "syscon"; diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c index 176bf0f..5a93d80 100644 --- a/drivers/mfd/syscon.c +++ b/drivers/mfd/syscon.c @@ -47,6 +47,7 @@ static struct syscon *of_syscon_register(struct device_node *np) struct syscon *syscon; struct regmap *regmap; void __iomem *base; + u32 bus_width; int ret; struct regmap_config syscon_config = syscon_regmap_config; @@ -69,6 +70,18 @@ static struct syscon *of_syscon_register(struct device_node *np) else if (of_property_read_bool(np, "little-endian")) syscon_config.val_format_endian = REGMAP_ENDIAN_LITTLE; + /* + * search for bus-width property in DT. If it is not provided, default + * to 32-bit. regmap_init_mmio will return an error if syscon_config's + * values are invalid so there is no need to check them here. + */ + ret = of_property_read_u32(np, "bus-width", &bus_width); + if (ret) + bus_width = 32; + + syscon_config.val_bits = bus_width; + syscon_config.reg_stride = syscon_config.val_bits / 8; + regmap = regmap_init_mmio(NULL, base, &syscon_config); if (IS_ERR(regmap)) { pr_err("regmap init failed\n"); -- 2.5.0
next prev parent reply other threads:[~2015-11-24 18:01 UTC|newest] Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top 2015-11-24 18:00 [PATCH v5 0/5] Add board support for TS-4800 Damien Riegel 2015-11-24 18:00 ` Damien Riegel 2015-11-24 18:00 ` [PATCH v5 1/5] of: add vendor prefix for Technologic Systems Damien Riegel 2015-11-24 18:00 ` Damien Riegel 2015-11-24 18:00 ` Damien Riegel [this message] 2015-11-24 18:00 ` [PATCH v5 2/5] mfd: syscon: add a DT property to set value width Damien Riegel 2015-11-24 18:00 ` [PATCH v5 3/5] watchdog: ts4800: add driver for TS-4800 watchdog Damien Riegel 2015-11-24 18:00 ` Damien Riegel 2015-11-24 18:08 ` Guenter Roeck 2015-11-24 18:08 ` Guenter Roeck 2015-11-24 18:00 ` [PATCH v5 4/5] ARM: imx_v6_v7_defconfig: add " Damien Riegel 2015-11-24 18:00 ` Damien Riegel 2015-11-24 18:00 ` [PATCH v5 5/5] ARM: dts: TS-4800: add basic device tree Damien Riegel 2015-11-24 18:00 ` Damien Riegel 2015-11-25 6:13 ` Shawn Guo 2015-11-25 6:13 ` Shawn Guo
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