Re: [PATCH 1/1] pinctrl: Add alternative way for specifying register bases

From: Sean Wang
Date: Sun Apr 14 2019 - 19:02:21 EST


Hi, Light

On Thu, Apr 11, 2019 at 8:15 PM Light Hsieh <light.hsieh@xxxxxxxxxxxx> wrote:
>
> The orginal PINCTRL_MTK_PARIS/PINCTRL_MTK_MOORE need more effort for
> specifying register bases when porting platform driver:
> 1. Write mtXXXX_pinctrl_register_base_name[] array in pinctrl-mtXXXX.c
> to specify names of register bases, for exmaple:
>
> static const char * const mt6765_pinctrl_register_base_names[] = {
> "iocfg0", "iocfg1", "iocfg2", "iocfg3", "iocfg4", "iocfg5",
> "iocfg6", "iocfg7",
> };
> 2. Write reg = <...>, ..., <...>; in mtXXXX.dts to specify register
> bases. Each member of reg contain address range cloned from
> pre-generated devicetree node.
> 3. Write reg-names = "...", ..., "..."; in mtXXXX.dts to specify
> names of register bases. The sequence of names in reg-names shall match
> sequence of names that specified in pinctrl-mtXXXX.c.
> Besides, the seqeunce of names in reg-names shall also match sequence of
> address range in reg, for exmaple:
>
> pio: pinctrl {
> compatible = "mediatek,mt6765-pinctrl";
> reg = <0 0x10005000 0 0x1000>,
> <0 0x10002C00 0 0x200>,
> <0 0x10002800 0 0x200>,
> <0 0x10002A00 0 0x200>,
> <0 0x10002000 0 0x200>,
> <0 0x10002200 0 0x200>,
> <0 0x10002400 0 0x200>,
> <0 0x10002600 0 0x200>,
> <0 0x1000b000 0 0x1000>;
> reg-names = "iocfg0", "iocfg1", "iocfg2", "iocfg3",
> "iocfg4", "iocfg5", "iocfg6", "iocfg7",
> "eint";
>
> To reduce porting effort, this patch add an alternative way for specifying
> register bases:
> 1. Write reg_bases = <...>, ..., <...>; and reg_base_eint = <&eint>;
> in mtXXXX.dtsi where members in reg_bases and &eint are labels for
> pre-generated devicetree nodes, for example:
> pio: pinctrl {
> compatible = "mediatek,mt6765-pinctrl";
> reg_bases = <&gpio0>,
> <&iocfg0>,
> <&iocfg1>,
> <&iocfg2>,
> <&iocfg3>,
> <&iocfg4>,
> <&iocfg5>,
> <&iocfg6>,
> <&iocfg7>;
> reg_base_eint = <&eint>;

reg and reg-names both are generic properties used in all of DT-based
device and driver, described in
Documentation/devicetree/bindings/resource-names.txt, but reg_based
and reg_base_eint aren't.

If these properties are not hardware specific related, I personally
will encourage reusing those generic properties and relevant helpers
because those generic properties handling in the base driver are
almost bug-free, well maintained and even keep be extended in the
future. This way can help driver people put more concentration on
hardware specific stuff in the driver.

>
> Since this pre-generated nodes had already specify address range,
> it is not necessary to specify address range again in pinctrl node.
>
> Using this way, porting effort is reduced and therefore typo can occur with
> less chance.
>
> Change-Id: I55f5e328919f4f736ca4b9f8d1593e069f179637
> ---
> drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c | 19 +++++---
> drivers/pinctrl/mediatek/pinctrl-paris.c | 62 ++++++++++++++++--------
> 2 files changed, 54 insertions(+), 27 deletions(-)
>
> diff --git a/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c b/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c
> index b1c3684..16b4863 100644
> --- a/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c
> +++ b/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c
> @@ -12,6 +12,7 @@
> #include <linux/platform_device.h>
> #include <linux/io.h>
> #include <linux/of_irq.h>
> +#include <linux/of_address.h>
>
> #include "mtk-eint.h"
> #include "pinctrl-mtk-common-v2.h"
> @@ -310,7 +311,7 @@ static int mtk_xt_set_gpio_as_eint(void *data, unsigned long eint_n)
>
> int mtk_build_eint(struct mtk_pinctrl *hw, struct platform_device *pdev)
> {
> - struct device_node *np = pdev->dev.of_node;
> + struct device_node *np = pdev->dev.of_node, *node;
> struct resource *res;
>
> if (!IS_ENABLED(CONFIG_EINT_MTK))
> @@ -323,13 +324,19 @@ int mtk_build_eint(struct mtk_pinctrl *hw, struct platform_device *pdev)
> if (!hw->eint)
> return -ENOMEM;
>
> - res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "eint");
> - if (!res) {
> - dev_err(&pdev->dev, "Unable to get eint resource\n");
> - return -ENODEV;
> + node = of_parse_phandle(np, "reg_base_eint", 0);
> + if (node) {
> + hw->eint->base = of_iomap(node, 0);
> + } else {
> + res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
> + "eint");
> + if (!res) {
> + dev_err(&pdev->dev, "Unable to get eint resource\n");
> + return -ENODEV;
> + }
> + hw->eint->base = devm_ioremap_resource(&pdev->dev, res);
> }
>
> - hw->eint->base = devm_ioremap_resource(&pdev->dev, res);
> if (IS_ERR(hw->eint->base))
> return PTR_ERR(hw->eint->base);
>
> diff --git a/drivers/pinctrl/mediatek/pinctrl-paris.c b/drivers/pinctrl/mediatek/pinctrl-paris.c
> index b59e108..8ddb995 100644
> --- a/drivers/pinctrl/mediatek/pinctrl-paris.c
> +++ b/drivers/pinctrl/mediatek/pinctrl-paris.c
> @@ -9,6 +9,7 @@
> * Hongzhou.Yang <hongzhou.yang@xxxxxxxxxxxx>
> */
>
> +#include <linux/of_address.h>
> #include <linux/gpio/driver.h>
> #include <dt-bindings/pinctrl/mt65xx.h>
> #include "pinctrl-paris.h"
> @@ -815,10 +816,11 @@ static int mtk_pctrl_build_state(struct platform_device *pdev)
> int mtk_paris_pinctrl_probe(struct platform_device *pdev,
> const struct mtk_pin_soc *soc)
> {
> + struct device_node *np = pdev->dev.of_node, *node;
> struct pinctrl_pin_desc *pins;
> struct mtk_pinctrl *hw;
> struct resource *res;
> - int err, i;
> + int err, i, get_base_pass;
>
> hw = devm_kzalloc(&pdev->dev, sizeof(*hw), GFP_KERNEL);
> if (!hw)
> @@ -828,31 +830,49 @@ int mtk_paris_pinctrl_probe(struct platform_device *pdev,
> hw->soc = soc;
> hw->dev = &pdev->dev;
>
> - if (!hw->soc->nbase_names) {
> - dev_err(&pdev->dev,
> - "SoC should be assigned at least one register base\n");
> - return -EINVAL;
> - }
> -
> - hw->base = devm_kmalloc_array(&pdev->dev, hw->soc->nbase_names,
> + if (hw->soc->nbase_names) {
> + hw->base = devm_kmalloc_array(&pdev->dev, hw->soc->nbase_names,
> sizeof(*hw->base), GFP_KERNEL);
> - if (!hw->base)
> - return -ENOMEM;
> + if (!hw->base)
> + return -ENOMEM;
> +
> + for (i = 0; i < hw->soc->nbase_names; i++) {
> + res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
> + hw->soc->base_names[i]);
> + if (!res) {
> + dev_err(&pdev->dev, "missing IO resource\n");
> + return -ENXIO;
> + }
>
> - for (i = 0; i < hw->soc->nbase_names; i++) {
> - res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
> - hw->soc->base_names[i]);
> - if (!res) {
> - dev_err(&pdev->dev, "missing IO resource\n");
> - return -ENXIO;
> + hw->base[i] = devm_ioremap_resource(&pdev->dev, res);
> + if (IS_ERR(hw->base[i]))
> + return PTR_ERR(hw->base[i]);
> }
>
> - hw->base[i] = devm_ioremap_resource(&pdev->dev, res);
> - if (IS_ERR(hw->base[i]))
> - return PTR_ERR(hw->base[i]);
> - }
> + hw->nbase = hw->soc->nbase_names;
> + } else {
> + for (get_base_pass = 0; get_base_pass < 2; get_base_pass++) {
> + for (i = 0;; i++) {
> + node = of_parse_phandle(np, "reg_bases", i);
> + if (!node)
> + break;
> + if (get_base_pass == 1)
> + hw->base[i] = of_iomap(node, 0);
> + of_node_put(node);
> + }
>
> - hw->nbase = hw->soc->nbase_names;
> + if (i == 0)
> + return -EINVAL;
> + if (get_base_pass == 0) {
> + hw->nbase = i;
> + hw->base = devm_kmalloc_array(&pdev->dev, i,
> + sizeof(*hw->base),
> + GFP_KERNEL | __GFP_ZERO);
> + if (IS_ERR(hw->base))
> + return PTR_ERR(hw->base);
> + }
> + }
> + }
>
> err = mtk_pctrl_build_state(pdev);
> if (err) {
> --
> 1.8.1.1.dirty
>