Re: [PATCH 2/2] pinctrl: Add simple pinmux driver using device tree data

Dong Aisheng
2012-02-08T01:53:51Z

On 2/4/12, Tony Lindgren <tony@atomide.com> wrote:
> * Tony Lindgren <tony@atomide.com> [120203 12:25]:
>> Add simple pinmux driver using device tree data.
>> +#define REG_NAME_LEN (sizeof(unsigned long) + 1)
>
> This is too short to contain the register name. Also the index
> for smux->names won't increase properly, so the names are wrong
> in debugfs.
>
>> +static struct pinctrl_desc smux_pinctrl_desc = {
>> + .name = DRIVER_NAME,
>> + .pctlops = &smux_pinctrl_ops,
>> + .pmxops = &smux_pinmux_ops,
>> + .confops = &smux_pinconf_ops,
>> + .owner = THIS_MODULE,
>> +};
>
> This needs to be dynamically allocated to support multiple
> driver instances as it also contains pins and npins.
>
> Updated patch below.
>
> Regards,
>
> Tony
>
> From: Tony Lindgren <tony@atomide.com>
> Date: Sat, 4 Feb 2012 09:56:24 -0800
> Subject: [PATCH] pinctrl: Add simple pinmux driver using device tree data
>
> Add simple pinmux driver using device tree data.
>
> Currently this driver only works on omap2+ series of
> processors, where there is either an 8 or 16-bit mux
> register for each pin. Support for other similar pinmux
> controllers could be added.
>
It's great to see such a driver trying to be common since we indeed
have some common part on handling function and group emuration since
most pinctrl drivers may reference the u300.
The most difference may be the function enable due to hw difference.
But i see that for DT case, it seems function and group creation may
also be a problem.

> Note that this patch does not yet support pinconf_ops
> or GPIO. Further, alternative mux modes are not yet
> handled.
>
> Signed-off-by: Tony Lindgren <tony@atomide.com>
>
> diff --git a/Documentation/devicetree/bindings/pinmux/pinctrl-simple.txt
> b/Documentation/devicetree/bindings/pinmux/pinctrl-simple.txt
> new file mode 100644
> index 0000000..ca1a48d
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/pinmux/pinctrl-simple.txt
> @@ -0,0 +1,62 @@
> +Generic simple device tree based pinmux driver
> +
> +Required properties:
> +- compatible : one of:
> + - "pinctrl-simple"
> + - "ti,omap2420-pinmux"
> + - "ti,omap2430-pinmux"
> + - "ti,omap3-pinmux"
> + - "ti,omap4-pinmux"
> +- reg : offset and length of the register set for the mux registers
> +- #pinmux-cells : width of the pinmux array, currently only 2 is supported
> +- pinctrl-simple,register-width : pinmux register access width
> +- pinctrl-simple,function-mask : mask of allowed pinmux function bits
> +- pinctrl-simple,function-off : function off mode for disabled state
> +- pinctrl-simple,pinconf-mask : mask of allowed pinconf bits
> +
> +Example:
> +
> + /* SoC common file, such as omap4.dtsi */
> + omap4_pmx_core: pinmux@4a100040 {
> + compatible = "ti,omap4-pinmux";
> + reg = <0x4a100040 0x0196>;
> + #address-cells = <1>;
> + #size-cells = <0>;
> + #pinmux-cells = <2>;
> + pinctrl-simple,register-width = <16>;
> + pinctrl-simple,function-mask = <0x7>;
> + pinctrl-simple,function-off = <0x7>;
> + pinctrl-simple,pinconf-mask = <0xfff8>;
> + };
> +
> + omap4_pmx_wkup: pinmux@4a31e040 {
> + compatible = "ti,omap4-pinmux";
> + reg = <0x4a31e040 0x0038>;
> + #address-cells = <1>;
> + #size-cells = <0>;
> + #pinmux-cells = <2>;
> + pinctrl-simple,register-width = <16>;
> + pinctrl-simple,function-mask = <0x7>;
> + pinctrl-simple,function-off = <0x7>;
> + pinctrl-simple,pinconf-mask = <0xfff8>;
> + };
> +
> + uart3: serial@48020000 {
> + compatible = "ti,omap4-uart";
> + ti,hwmods = "uart3";
> + clock-frequency = <48000000>;
> + }
> +
> + /* board specific .dts file, such as omap4-sdp.dts */
> + pinmux@4a100040 {
> + pmx_uart3: pinconfig-uart3 {
> + mux = <0x0104 0x100
> + 0x0106 0x0>;
> + };
> + };
> + };
> +
> + serial@48020000 {
> + pinctrl = <&pmx_uart3>;
> + };
> +
> diff --git a/drivers/pinctrl/Kconfig b/drivers/pinctrl/Kconfig
> index afaf885..73848b1 100644
> --- a/drivers/pinctrl/Kconfig
> +++ b/drivers/pinctrl/Kconfig
> @@ -42,6 +42,12 @@ config PINCTRL_COH901
> COH 901 335 and COH 901 571/3. They contain 3, 5 or 7
> ports of 8 GPIO pins each.
>
> +config PINCTRL_SIMPLE
> + tristate "Simple device tree based pinmux driver"
> + depends on OF
> + help
> + This selects the device tree based generic pinmux driver.
> +
> endmenu
>
> endif
> diff --git a/drivers/pinctrl/Makefile b/drivers/pinctrl/Makefile
> index 827601c..4b05649 100644
> --- a/drivers/pinctrl/Makefile
> +++ b/drivers/pinctrl/Makefile
> @@ -8,3 +8,4 @@ obj-$(CONFIG_PINCONF) += pinconf.o
> obj-$(CONFIG_PINCTRL_SIRF) += pinctrl-sirf.o
> obj-$(CONFIG_PINCTRL_U300) += pinctrl-u300.o
> obj-$(CONFIG_PINCTRL_COH901) += pinctrl-coh901.o
> +obj-$(CONFIG_PINCTRL_SIMPLE) += pinctrl-simple.o
> diff --git a/drivers/pinctrl/pinctrl-simple.c
> b/drivers/pinctrl/pinctrl-simple.c
> new file mode 100644
> index 0000000..0018d67
> --- /dev/null
> +++ b/drivers/pinctrl/pinctrl-simple.c
> @@ -0,0 +1,1291 @@
> +/*
> + * Generic simple device tree based pinmux driver
> + *
> + * Copyright (C) 2012 Texas Instruments, Inc.
> + *
> + * This file is licensed under the terms of the GNU General Public
> + * License version 2. This program is licensed "as is" without any
> + * warranty of any kind, whether express or implied.
> + */
> +
> +#include <linux/init.h>
> +#include <linux/module.h>
> +#include <linux/io.h>
> +#include <linux/slab.h>
> +#include <linux/err.h>
> +#include <linux/list.h>
> +
> +#include <linux/of.h>
> +#include <linux/of_device.h>
> +#include <linux/of_address.h>
> +
> +#include <linux/pinctrl/pinctrl.h>
> +#include <linux/pinctrl/pinmux.h>
> +#include <linux/pinctrl/machine.h>
> +
> +#include "core.h"
> +
> +#define PMX_MUX_NAME "mux"
> +#define PMX_PINCTRL_NAME "pinctrl"
> +#define PMX_MUX_CELLS "#pinmux-cells"
> +#define DRIVER_NAME "pictrl-simple"
> +#define REG_NAME_LEN ((sizeof(unsigned long) * 2) + 1)
> +
> +static LIST_HEAD(smux_maps); /* Global device to pinmux map */
> +static LIST_HEAD(smux_pingroups); /* Global list of pingroups */
> +static LIST_HEAD(smux_functions); /* Global list of functions */
> +static DEFINE_MUTEX(smux_mutex);
> +
> +/**
> + * struct smux_pingroup - pingroups for a function
> + * @smux: pinmux controller instance
> + * @np: pinggroup device node pointer
> + * @name: pingroup name
> + * @gpins: array of the pins in the group
> + * @ngpins: number of pins in the group
> + */
> +struct smux_pingroup {
> + struct smux_device *smux;
> + struct device_node *np;
> + char *name;
> + int *gpins;
> + int ngpins;
> + struct list_head node;
> +};
> +
> +/**
> + * struct smux_func_vals - mux function register offset and default value
> pair
> + * @reg: register virtual address
> + * @defval: default value
> + */
> +struct smux_func_vals {
> + void __iomem *reg;
> + unsigned defval;
> +};
> +
> +/**
> + * struct smux_function - pinmux function
> + * @smux: pinmux controller instance
> + * @np: mux device node pointer
> + * @name: pinmux function name
> + * @vals: register and default values array
> + * @nvals: number of entries in vals array
> + * @pgnames: array of pingroup names the function uses
> + * @npgnames: number of pingroup names the function uses
> + * @node: list node
> + *
> + * Note that np is needed to match pinctrl entry to mux entry.
> + */
> +struct smux_function {
> + struct smux_device *smux;
> + struct device_node *np;
> + char *name;
> + struct smux_func_vals *vals;
> + unsigned nvals;
> + const char **pgnames;
> + int npgnames;
> + struct list_head node;
> +};
> +
> +/**
> + * struct smux_map - wrapper for device to pinmux map
> + * @smux: pinmux controller instance
> + * @map: device to pinmux map
> + * @node: list node
> + */
> +struct smux_map {
> + struct smux_device *smux;
> + struct pinmux_map map;
> + struct list_head node;
> +};
> +
> +/**
> + * struct smux_data - data arrays needed by pinctrl framework
> + * @pa: pindesc array
> + * @ma: pinmap array
> + * @cur: index to current element
> + * @max: last element in the array
> + *
> + */
> +struct smux_data {
> + union {
> + struct pinctrl_pin_desc *pa;
> + struct pinmux_map *ma;
> + };
> + int cur;
> + int max;
> +};
> +
> +/**
> + * struct smux_name - register name for a pin
> + * @name: name of the pinmux register
> + */
> +struct smux_name {
> + char name[REG_NAME_LEN];
> +};
> +
> +/**
> + * struct smux_device - mux device instance
> + * @res: resources
> + * @base: virtual address of the controller
> + * @size: size of the ioremapped area
> + * @dev: device entry
> + * @pctl: pin controller device
> + * @width: bits per mux register
> + * @fmask: function register mask
> + * @fshift: function register shift
> + * @foff: value to turn mux off
> + * @cmask: pinconf mask
> + * @fmax: max number of functions in fmask
> + * @cells: width of the mux array
> + * @names: array of register names for pins
> + * @pins: physical pins on the SoC
> + * @maps: device to mux function mappings
> + * @pgtree: pingroup index radix tree
> + * @ftree: function index radix tree
> + * @ngroups: number of pingroups
> + * @nfuncs: number of functions
> + * @desc: pin controller descriptor
> + * @read: register read function to use
> + * @write: register write function to use
> + */
> +struct smux_device {
> + struct resource *res;
> + void __iomem *base;
> + unsigned size;
> + struct device *dev;
> + struct pinctrl_dev *pctl;
> +
> + unsigned width;
> + unsigned fmask;
> + unsigned fshift;
> + unsigned foff;
> + unsigned cmask;
> + unsigned fmax;
> + unsigned cells;
> +
> + struct smux_name *names;
> + struct smux_data pins;
> + struct smux_data maps;
> + struct radix_tree_root pgtree;
> + struct radix_tree_root ftree;
> + unsigned ngroups;
> + unsigned nfuncs;
> +
> + struct pinctrl_desc *desc;
> +
> + unsigned (*read)(void __iomem *reg);
> + void (*write)(unsigned val, void __iomem *reg);
> +};
> +
> +static unsigned __maybe_unused smux_readb(void __iomem *reg)
> +{
> + return readb(reg);
> +}
> +
> +static unsigned __maybe_unused smux_readw(void __iomem *reg)
> +{
> + return readw(reg);
> +}
> +
> +static unsigned __maybe_unused smux_readl(void __iomem *reg)
> +{
> + return readl(reg);
> +}
> +
> +static void __maybe_unused smux_writeb(unsigned val, void __iomem *reg)
> +{
> + writeb(val, reg);
> +}
> +
> +static void __maybe_unused smux_writew(unsigned val, void __iomem *reg)
> +{
> + writew(val, reg);
> +}
> +
> +static void __maybe_unused smux_writel(unsigned val, void __iomem *reg)
> +{
> + writel(val, reg);
> +}
> +
> +static int smux_list_groups(struct pinctrl_dev *pctldev, unsigned
> gselector)
> +{
> + struct smux_device *smux;
> +
> + smux = pinctrl_dev_get_drvdata(pctldev);
> + if (gselector >= smux->ngroups)
> + return -EINVAL;
> +
> + return 0;
> +}
> +
> +static const char *smux_get_group_name(struct pinctrl_dev *pctldev,
> + unsigned gselector)
> +{
> + struct smux_device *smux;
> + struct smux_pingroup *group;
> +
> + smux = pinctrl_dev_get_drvdata(pctldev);
> + group = radix_tree_lookup(&smux->pgtree, gselector);
> + if (!group) {
> + dev_err(smux->dev, "%s could not find pingroup%i\n",
> + __func__, gselector);
> + return NULL;
> + }
> +
> + return group->name;
> +}
> +
> +static int smux_get_group_pins(struct pinctrl_dev *pctldev,
> + unsigned gselector,
> + const unsigned **pins,
> + unsigned *npins)
> +{
> + struct smux_device *smux;
> + struct smux_pingroup *group;
> +
> + smux = pinctrl_dev_get_drvdata(pctldev);
> + group = radix_tree_lookup(&smux->pgtree, gselector);
> + if (!group) {
> + dev_err(smux->dev, "%s could not find pingroup%i\n",
> + __func__, gselector);
> + return -EINVAL;
> + }
> +
> + *pins = group->gpins;
> + *npins = group->ngpins;
> +
> + return 0;
> +}
> +
> +static void smux_pin_dbg_show(struct pinctrl_dev *pctldev,
> + struct seq_file *s,
> + unsigned offset)
> +{
> + seq_printf(s, " " DRIVER_NAME);
> +}
> +
> +static struct pinctrl_ops smux_pinctrl_ops = {
> + .list_groups = smux_list_groups,
> + .get_group_name = smux_get_group_name,
> + .get_group_pins = smux_get_group_pins,
> + .pin_dbg_show = smux_pin_dbg_show,
> +};
> +
> +static int smux_list_functions(struct pinctrl_dev *pctldev, unsigned
> fselector)
> +{
> + struct smux_device *smux;
> +
> + smux = pinctrl_dev_get_drvdata(pctldev);
> + if (fselector >= smux->nfuncs)
> + return -EINVAL;
> +
> + return 0;
> +}
> +
> +static const char *smux_get_function_name(struct pinctrl_dev *pctldev,
> + unsigned fselector)
> +{
> + struct smux_device *smux;
> + struct smux_function *func;
> +
> + smux = pinctrl_dev_get_drvdata(pctldev);
> + func = radix_tree_lookup(&smux->ftree, fselector);
> + if (!func) {
> + dev_err(smux->dev, "%s could not find function%i\n",
> + __func__, fselector);
> + return NULL;
> + }
> +
> + return func->name;
> +}
> +
> +static int smux_get_function_groups(struct pinctrl_dev *pctldev,
> + unsigned fselector,
> + const char * const **groups,
> + unsigned * const ngroups)
> +{
> + struct smux_device *smux;
> + struct smux_function *func;
> +
> + smux = pinctrl_dev_get_drvdata(pctldev);
> + func = radix_tree_lookup(&smux->ftree, fselector);
> + if (!func) {
> + dev_err(smux->dev, "%s could not find function%i\n",
> + __func__, fselector);
> + return -EINVAL;
> + }
> + *groups = func->pgnames;
> + *ngroups = func->npgnames;
> +
> + return 0;
> +}
> +
> +static int smux_enable(struct pinctrl_dev *pctldev, unsigned fselector,
> + unsigned group)
> +{
> + struct smux_device *smux;
> + struct smux_function *func;
> + int i;
> +
> + smux = pinctrl_dev_get_drvdata(pctldev);
> + func = radix_tree_lookup(&smux->ftree, fselector);
> + if (!func)
> + return -EINVAL;
> +
> + dev_dbg(smux->dev, "enabling function%i %s\n",
> + fselector, func->name);
> +
> + for (i = 0; i < func->nvals; i++) {
> + struct smux_func_vals *vals;
> + unsigned val;
> +
> + vals = &func->vals[i];
> + val = smux->read(vals->reg);
> + val &= ~(smux->cmask | smux->fmask);
> + val |= vals->defval;
> + smux->write(val, vals->reg);
> + }
> +
> + return 0;
> +}
> +
> +/*
> + * REVISIT: We may not always have a single disable value for a register,
> + * but this can be handled with alternative modes once the DT binding is
> + * available for those.
> + */
> +static void smux_disable(struct pinctrl_dev *pctldev, unsigned fselector,
> + unsigned group)
> +{
> + struct smux_device *smux;
> + struct smux_function *func;
> + int i;
> +
> + smux = pinctrl_dev_get_drvdata(pctldev);
> + func = radix_tree_lookup(&smux->ftree, fselector);
> + if (!func) {
> + dev_err(smux->dev, "%s could not find function%i\n",
> + __func__, fselector);
> + return;
> + }
> +
> + dev_dbg(smux->dev, "disabling function%i %s\n",
> + fselector, func->name);
> +
> + for (i = 0; i < func->nvals; i++) {
> + struct smux_func_vals *vals;
> + unsigned val;
> +
> + vals = &func->vals[i];
> + val = smux->read(vals->reg);
> + val &= ~(smux->cmask | smux->fmask);
> + val |= smux->foff << smux->fshift;
> + smux->write(val, vals->reg);
> + }
> +}
> +
> +static int smux_request_gpio(struct pinctrl_dev *pctldev,
> + struct pinctrl_gpio_range *range, unsigned offset)
> +{
> + return -ENOTSUPP;
> +}
> +
> +static struct pinmux_ops smux_pinmux_ops = {
> + .list_functions = smux_list_functions,
> + .get_function_name = smux_get_function_name,
> + .get_function_groups = smux_get_function_groups,
> + .enable = smux_enable,
> + .disable = smux_disable,
> + .gpio_request_enable = smux_request_gpio,
> +};
> +
> +static int smux_pinconf_get(struct pinctrl_dev *pctldev,
> + unsigned pin, unsigned long *config)
> +{
> + return -ENOTSUPP;
> +}
> +
> +static int smux_pinconf_set(struct pinctrl_dev *pctldev,
> + unsigned pin, unsigned long config)
> +{
> + return -ENOTSUPP;
> +}
> +
> +static int smux_pinconf_group_get(struct pinctrl_dev *pctldev,
> + unsigned group, unsigned long *config)
> +{
> + return -ENOTSUPP;
> +}
> +
> +static int smux_pinconf_group_set(struct pinctrl_dev *pctldev,
> + unsigned group, unsigned long config)
> +{
> + return -ENOTSUPP;
> +}
> +
> +static void smux_pinconf_dbg_show(struct pinctrl_dev *pctldev,
> + struct seq_file *s, unsigned offset)
> +{
> +}
> +
> +static void smux_pinconf_group_dbg_show(struct pinctrl_dev *pctldev,
> + struct seq_file *s, unsigned selector)
> +{
> +}
> +
> +static struct pinconf_ops smux_pinconf_ops = {
> + .pin_config_get = smux_pinconf_get,
> + .pin_config_set = smux_pinconf_set,
> + .pin_config_group_get = smux_pinconf_group_get,
> + .pin_config_group_set = smux_pinconf_group_set,
> + .pin_config_dbg_show = smux_pinconf_dbg_show,
> + .pin_config_group_dbg_show = smux_pinconf_group_dbg_show,
> +};
> +
> +/**
> + * smux_add_pin() - add a pin to the static per controller pin array
> + * @smux: smux driver instance
> + * @offset: register offset from base
> + */
> +static int __init smux_add_pin(struct smux_device *smux, unsigned offset)
> +{
> + struct pinctrl_pin_desc *pin;
> + struct smux_name *pn;
> + char *name;
> + int i;
> +
> + i = smux->pins.cur;
Can we drop cur if it's only temply used for add pin.

> + if (i > smux->pins.max + 1) {
> + dev_err(smux->dev, "too many pins, max %i\n",
> + smux->pins.max);
> + return -ENOMEM;
> + }
> +
> + pin = &smux->pins.pa[i];
> + pn = &smux->names[i];
> + name = pn->name;
> + sprintf(name, "%lx",
> + (unsigned long)smux->res->start + offset);
> + pin->name = name;
I'm wondering how about other people do not want the reg address to be PIN name?
It's less meaningful.

> + pin->number = i;
> + smux->pins.cur++;
> +
> + return i;
> +}
> +
> +/**
> + * smux_allocate_pin_table() - adds all the pins for the pinmux controller
> + * @smux: smux driver instance
> + *
> + * In case of errors, resources are freed in smux_free_resources.
> + */
> +static int __init smux_allocate_pin_table(struct smux_device *smux)
> +{
> + int mux_bytes, i;
> +
> + mux_bytes = smux->width / BITS_PER_BYTE;
> + smux->pins.max = smux->size / mux_bytes;
> +
The main issue for IMX to use this driver is that IMX pins number can
not be calculated in this way
since the imx pin controller reg range contains mux reg range and
config reg range as well as a few other misc registers
And it seems it's also not fit for Tegra since Tegra2's one register
may involve many pins.
This may need some proper way to fix.

> + dev_dbg(smux->dev, "allocating %i muxable pins\n",
> + smux->pins.max);
> + smux->pins.pa = devm_kzalloc(smux->dev,
> + sizeof(*smux->pins.pa) * smux->pins.max
> + GFP_KERNEL);
> + if (!smux->pins.pa)
> + return -ENOMEM;
> +
> + smux->names = devm_kzalloc(smux->dev,
> + sizeof(struct smux_name) * smux->pins.max,
> + GFP_KERNEL);
> + if (!smux->names)
> + return -ENOMEM;
> +
> + smux->desc->pins = smux->pins.pa;
> + smux->desc->npins = smux->pins.max--;
> +
> + for (i = 0; i <= smux->desc->npins; i++) {
> + unsigned offset;
> + int res;
> +
> + offset = i * mux_bytes;
> + res = smux_add_pin(smux, offset);
> + if (res < 0) {
> + dev_err(smux->dev, "error adding pins: %i\n", res);
> + return res;
> + }
> + }
> +
> + return 0;
> +}
> +
> +/**
> + * smux_add_function() - adds a new function to the function list
> + * @smux: smux driver instance
> + * @np: device node of the mux entry
> + * @name: name of the function
> + * @vals: array of mux register value pairs used by the function
> + * @nvals: number of mux register value pairs
> + * @pgnames: array of pingroup names for the function
> + * @npgnames: number of pingroup names
> + */
> +static int __init smux_add_function(struct smux_device *smux,
> + struct device_node *np,
> + const char *name,
> + struct smux_func_vals *vals,
> + unsigned nvals,
> + const char **pgnames,
> + unsigned npgnames)
> +{
> + struct smux_function *function;
> +
> + function = devm_kzalloc(smux->dev, sizeof(*function), GFP_KERNEL);
> + if (!function)
> + return -ENOMEM;
> +
> + function->name = kstrdup(name, GFP_KERNEL);
> + if (!function->name) {
> + devm_kfree(smux->dev, function);
> + return -ENOMEM;
> + }
> +
> + function->np = np;
> + function->smux = smux;
> + function->vals = vals;
> + function->nvals = nvals;
> + function->pgnames = pgnames;
> + function->npgnames = npgnames;
> +
> + mutex_lock(&smux_mutex);
> + list_add_tail(&function->node, &smux_functions);
> + radix_tree_insert(&smux->ftree, smux->nfuncs, function);
> + smux->nfuncs++;
> + mutex_unlock(&smux_mutex);
> +
> + return 0;
> +}
> +
> +/**
> + * smux_add_pingroup() - add a pingroup to the pingroup list
> + * @smux: smux driver instance
> + * @np: device node of the mux entry
> + * @name: name of the pingroup
> + * @gpins: array of the pins that belong to the group
> + * @ngpins: number of pins in the group
> + */
> +static int __init smux_add_pingroup(struct smux_device *smux,
> + struct device_node *np,
> + const char *name,
> + int *gpins,
> + int ngpins)
> +{
> + struct smux_pingroup *pingroup;
> +
> + pingroup = devm_kzalloc(smux->dev, sizeof(*pingroup), GFP_KERNEL);
> + if (!pingroup)
> + return -ENOMEM;
> +
> + pingroup->name = kstrdup(name, GFP_KERNEL);
> + if (!pingroup->name) {
> + devm_kfree(smux->dev, pingroup);
> + return -ENOMEM;
> + }
> +
> + pingroup->np = np;
> + pingroup->smux = smux;
> + pingroup->gpins = gpins;
> + pingroup->ngpins = ngpins;
> +
> + mutex_lock(&smux_mutex);
> + list_add_tail(&pingroup->node, &smux_pingroups);
> + radix_tree_insert(&smux->pgtree, smux->ngroups, pingroup);
> + smux->ngroups++;
> + mutex_unlock(&smux_mutex);
> +
> + return 0;
> +}
> +
> +/**
> + * smux_get_pin_by_offset() - get a pin index based on the register offset
> + * @smux: smux driver instance
> + * @offset: register offset from the base
> + *
> + * Note that this is OK for now as the pins are in a static array and
> + * the radix tree number stays the same.
> + */
> +static int __init smux_get_pin_by_offset(struct smux_device *smux,
> + unsigned offset)
> +{
> + unsigned index;
> +
> + if (offset >= smux->size) {
> + dev_err(smux->dev, "mux offset out of range: %04x (%04x)\n",
> + offset, smux->size);
> + return -EINVAL;
> + }
> +
> + index = offset / (smux->width / BITS_PER_BYTE);
> +
> + return index;
> +}
> +
> +/**
> + * smux_parse_one_pinmux_entry() - parses a device tree mux entry
> + * @smux: smux driver instance
> + * @np: device node of the mux entry
> + *
> + * Note that this currently supports only #pinmux-cells = 2.
> + * This could be improved to parse controllers that have multiple
> + * registers per mux.
> + */
> +static int __init smux_parse_one_pinmux_entry(struct smux_device *smux,
> + struct device_node *np)
> +{
> + struct smux_func_vals *vals;
> + const __be32 *mux;
> + int size, rows, *pins, index = 0, found = 0, res = -ENOMEM;
> + const char **pgnames;
> +
> + if (smux->cells != 2) {
> + dev_err(smux->dev, "unhandled %s: %i\n",
> + PMX_MUX_CELLS,
> + smux->cells);
> + return -EINVAL;
> + }
> +
> + mux = of_get_property(np, PMX_MUX_NAME, &size);
> + if ((!mux) || (size < sizeof(*mux) * smux->cells)) {
> + dev_err(smux->dev, "bad data for mux %s\n",
> + np->full_name);
> + return -EINVAL;
> + }
> + size /= sizeof(*mux); /* Number of elements in array */
> + rows = size / smux->cells;
> +
> + vals = devm_kzalloc(smux->dev, sizeof(*vals) * rows, GFP_KERNEL);
> + if (!vals)
> + return -ENOMEM;
> +
> + pins = devm_kzalloc(smux->dev, sizeof(*pins) * rows, GFP_KERNEL);
> + if (!pins)
> + goto free_vals;
> +
> + pgnames = devm_kzalloc(smux->dev, sizeof(*pgnames), GFP_KERNEL);
> + if (!pgnames)
> + goto free_pins;
> +
> + while (index < size) {
> + unsigned offset, defval;
> + int pin;
> +
> + offset = be32_to_cpup(mux + index++);
> + defval = be32_to_cpup(mux + index++);
> + vals[found].reg = smux->base + offset;
> + vals[found].defval = defval;
>
> + pin = smux_get_pin_by_offset(smux, offset);
> + if (pin < 0) {
> + dev_info(smux->dev,
> + "could not add functions for mux %ux\n",
> + offset);
> + break;
> + }
> + pins[found++] = pin;
> + }
> +
> + pgnames[0] = np->name;
> + res = smux_add_function(smux, np, np->name, vals, found, pgnames, 1);
> + if (res < 0)
> + goto free_pgnames;
> +
> + res = smux_add_pingroup(smux, np, np->name, pins, found);
> + if (res < 0)
> + goto free_pgnames;
> +
> + return 0;
> +
> +free_pgnames:
> + devm_kfree(smux->dev, pgnames);
> +
> +free_pins:
> + devm_kfree(smux->dev, pins);
> +
> +free_vals:
> + devm_kfree(smux->dev, vals);
> +
> + return res;
> +}
> +
> +/**
> + * smux_get_function_by_node() - find a function by node
> + * @smux: smux driver instance
> + * @np: device node of the mux entry
> + */
> +static struct smux_function *
> +__init smux_get_function_by_node(struct smux_device *smux,
> + struct device_node *np)
> +{
> + struct smux_function *function;
> +
> + mutex_lock(&smux_mutex);
> + list_for_each_entry(function, &smux_functions, node) {
> + if (smux != function->smux)
> + continue;
> +
> + if (function->np == np)
> + goto unlock;
> + }
> + function = NULL;
> +
> +unlock:
> + mutex_unlock(&smux_mutex);
> +
> + return function;
> +}
> +
> +/**
> + * smux_rename_function() - renames a function added earlier
> + * @function: existing function
> + * @new_name: new name for the function
> + *
> + * This is needed to avoid adding multiple function entries.
> + * We first parse all the device tree mux entries, and then
> + * parse the device pinconfig entries. This allows us to rename
> + * mux entry to match the device pinconfig naming.
> + */
> +static int __init smux_rename_function(struct smux_function *function,
> + const char *new_name)
> +{
> + char *name;
> +
> + if (!new_name)
> + return -EINVAL;
> +
> + name = kstrdup(new_name, GFP_KERNEL);
> + if (!name)
> + return -ENOMEM;
> +
> + mutex_lock(&smux_mutex);
> + kfree(function->name);
> + function->name = name;
> + mutex_unlock(&smux_mutex);
> +
> + return 0;
> +}
> +
> +/**
> + * smux_add_map() - adds a new map to the map list
> + * @smux: smux driver instance
> + * @np: device node of the mux entry
> + *
> + * Note that pctldev will get populated later on as it is
> + * not available until after pinctrl_register().
> + */
> +static int __init smux_add_map(struct smux_device *smux,
> + struct device_node *np)
> +{
> + struct platform_device *pdev = NULL;
> + struct smux_map *smap;
> + struct pinmux_map *map;
> + const char *new_name;
> + int ret;
> +
> + pdev = of_find_device_by_node(np);
> + new_name = np->full_name;
> +
> + mutex_lock(&smux_mutex);
> + list_for_each_entry(smap, &smux_maps, node) {
> + const char *existing_name = smap->map.name;
> +
> + if (smap->smux != smux)
> + continue;
> +
> + if (!strcmp(new_name, existing_name)) {
> + dev_info(smux->dev, "map already exists for %s\n",
> + existing_name);
> + ret = -EEXIST;
> + goto unlock;
> + }
> + }
> +
> + smap = devm_kzalloc(smux->dev, sizeof(*smap), GFP_KERNEL);
> + if (!smap) {
> + ret = -ENOMEM;
> + goto unlock;
> + }
> + smap->smux = smux;
> + if (smux->pctl && smux->pctl->dev)
> + smap->map.ctrl_dev = smux->pctl->dev;
> + map = &smap->map;
> +
> + map->dev = smux->dev;
> + map->name = kstrdup(new_name, GFP_KERNEL);
> + if (!map->name) {
> + ret = -ENOMEM;
> + devm_kfree(smux->dev, smap);
> + goto unlock;
> + }
> + map->function = map->name;
> + list_add_tail(&smap->node, &smux_maps);
> + ret = 0;
> +
> +unlock:
> + mutex_unlock(&smux_mutex);
> +
> + return ret;
> +}
> +
> +/**
> + * smux_parse_one_pinctrl_entry() - parses a device tree pinctrl entry
> + * @smux: smux driver instance
> + * @np: device node for mux entry
> + */
> +static int __init smux_parse_one_pinctrl_entry(struct smux_device *smux,
> + struct device_node *np)
> +{
> + int count = 0;
> +
> + do {
> + struct device_node *mux_np;
> + struct smux_function *function;
> + int res;
> +
> + mux_np = of_parse_phandle(np, PMX_PINCTRL_NAME,
> + count);
> + if (!mux_np)
> + break;
> +
> + function = smux_get_function_by_node(smux, mux_np);
> + if (!function)
> + break;
> +
> + res = smux_rename_function(function, np->full_name);
A little unclear for rename here.
Can we find a better way?

> + if (res < 0) {
> + dev_err(smux->dev, "could not rename %s to %s\n",
> + function->name, np->full_name);
> + break;
> + }
> +
> + res = smux_add_map(smux, np);
> + if (res < 0) {
> + dev_err(smux->dev, "could not add mapping for %s\n",
> + np->full_name);
> + break;
> + }
> + } while (++count);
This 'while' is for what? Define multi pinctrl properties?

> +
> + return count;
> +}
> +
> +/**
> + * smux_load_mux_register() - parses all the device tree mux entries
> + * @smux: smux driver instance
> + */
> +static int __init smux_load_mux_registers(struct smux_device *smux)
> +{
> + struct device_node *np;
> + int ret;
> +
> + for_each_child_of_node(smux->dev->of_node, np) {
> + ret = smux_parse_one_pinmux_entry(smux, np);
> + }
> +
> + for_each_node_with_property(np, PMX_PINCTRL_NAME) {
> + ret = smux_parse_one_pinctrl_entry(smux, np);

Can we put this in pinctrl core?
Just like something mentioned in my last proposal that pinctrl core
does the common pinmux node search, pinmux map table process and
register.
https://lkml.org/lkml/2012/2/3/276
That could be a very easy and flexible pinctrl binding.

> + }
> +
> + return 0;
> +}
> +
> +/**
> + * smux_populate_map() - populates device map for
> pinmux_register_mappings()
> + * @smux: smux driver instance
> + *
> + * Note that we need to fill in the ctrl_dev here as it's not known earlier
> + * before pinctrl_register().
> + */
> +static int __init smux_populate_map(struct smux_device *smux)
> +{
> + struct smux_map *smap;
> + int i = 0, ret;
> +
> + mutex_lock(&smux_mutex);
> + list_for_each_entry(smap, &smux_maps, node) {
> + if (smap->smux != smux)
> + continue;
> + smap->map.ctrl_dev = smux->pctl->dev;
> + i++;
> + }
> + if (!i) {
> + dev_err(smux->dev, "no maps found\n");
> + ret = -ENODEV;
> + goto unlock;
> + }
> +
> + dev_dbg(smux->dev, "allocating %i entries for map table\n", i);
> + smux->maps.ma = devm_kzalloc(smux->dev, sizeof(*smux->maps.ma) * i,
> + GFP_KERNEL);
> + if (!smux->maps.ma) {
> + ret = -ENOMEM;
> + goto unlock;
> + }
> +
> + i = 0;
> + list_for_each_entry(smap, &smux_maps, node) {
> + struct pinmux_map *map = &smux->maps.ma[i];
> +
> + if (smap->smux != smux)
> + continue;
> +
> + *map = smap->map;
> + i++;
> + }
> + smux->maps.max = i - 1;
> + ret = i;
> +
> +unlock:
> + mutex_unlock(&smux_mutex);
> +
> + return ret;
> +}
> +
> +/**
> + * smux_free_maps() - free memory used by device maps
> + * @smux: smux driver instance
> + */
> +static void smux_free_maps(struct smux_device *smux)
> +{
> + struct list_head *pos, *tmp;
> +
> + mutex_lock(&smux_mutex);
> + list_for_each_safe(pos, tmp, &smux_maps) {
> + struct smux_map *smap;
> +
> + smap = list_entry(pos, struct smux_map, node);
> + if (smap->smux != smux)
> + continue;
> +
> + kfree(smap->map.name);
> + list_del(&smap->node);
> + devm_kfree(smux->dev, smap);
> + }
> + if (smux->maps.ma)
> + devm_kfree(smux->dev, smux->maps.ma);
> + mutex_unlock(&smux_mutex);
> +}
> +
> +/**
> + * smux_free_funcs() - free memory used by functions
> + * @smux: smux driver instance
> + */
> +static void smux_free_funcs(struct smux_device *smux)
> +{
> + struct list_head *pos, *tmp;
> + int i;
> +
> + mutex_lock(&smux_mutex);
> + for (i = 0; i < smux->nfuncs; i++) {
> + struct smux_function *func;
> +
> + func = radix_tree_lookup(&smux->ftree, i);
> + if (!func)
> + continue;
> + radix_tree_delete(&smux->ftree, i);
> + }
> + list_for_each_safe(pos, tmp, &smux_functions) {
> + struct smux_function *function;
> +
> + function = list_entry(pos, struct smux_function, node);
> + if (function->smux != smux)
> + continue;
> +
> + kfree(function->name);
> + if (function->vals)
> + devm_kfree(smux->dev, function->vals);
> + if (function->pgnames)
> + devm_kfree(smux->dev, function->pgnames);
> + list_del(&function->node);
> + devm_kfree(smux->dev, function);
> + }
> + mutex_unlock(&smux_mutex);
> +}
> +
> +/**
> + * smux_free_pingroups() - free memory used by pingroups
> + * @smux: smux driver instance
> + */
> +static void smux_free_pingroups(struct smux_device *smux)
> +{
> + struct list_head *pos, *tmp;
> + int i;
> +
> + mutex_lock(&smux_mutex);
> + for (i = 0; i < smux->ngroups; i++) {
> + struct smux_pingroup *pingroup;
> +
> + pingroup = radix_tree_lookup(&smux->pgtree, i);
> + if (!pingroup)
> + continue;
> + radix_tree_delete(&smux->pgtree, i);
> + }
> + list_for_each_safe(pos, tmp, &smux_pingroups) {
> + struct smux_pingroup *pingroup;
> +
> + pingroup = list_entry(pos, struct smux_pingroup, node);
> + if (pingroup->smux != smux)
> + continue;
> +
> + kfree(pingroup->name);
> + list_del(&pingroup->node);
> + devm_kfree(smux->dev, pingroup);
> + }
> + mutex_unlock(&smux_mutex);
> +}
> +
> +/**
> + * smux_free_resources() - free memory used by this driver
> + * @smux: smux driver instance
> + */
> +static void smux_free_resources(struct smux_device *smux)
> +{
> + if (smux->pctl)
> + pinctrl_unregister(smux->pctl);
> +
> + smux_free_maps(smux);
> + smux_free_funcs(smux);
> + smux_free_pingroups(smux);
> +
> + if (smux->desc)
> + devm_kfree(smux->dev, smux->desc);
> + if (smux->pins.pa)
> + devm_kfree(smux->dev, smux->pins.pa);
> + if (smux->names)
> + devm_kfree(smux->dev, smux->names);
> +}
> +
> +/**
> + * smux_register() - initializes and registers with pinctrl framework
> + * @smux: smux driver instance
> + */
> +static int __init smux_register(struct smux_device *smux)
> +{
> + int ret;
> +
> + if (!smux->dev->of_node)
> + return -ENODEV;
> +
> + smux->desc = devm_kzalloc(smux->dev, sizeof(*smux->desc), GFP_KERNEL);
> + if (!smux->desc)
> + goto free;
> + smux->desc->name = DRIVER_NAME;
> + smux->desc->pctlops = &smux_pinctrl_ops;
> + smux->desc->pmxops = &smux_pinmux_ops;
> + smux->desc->confops = &smux_pinconf_ops;
> + smux->desc->owner = THIS_MODULE;
> +
> + ret = smux_allocate_pin_table(smux);
> + if (ret < 0)
> + goto free;
> +
> + ret = smux_load_mux_registers(smux);
> + if (ret < 0)
> + goto free;
> +
> + smux->pctl = pinctrl_register(smux->desc, smux->dev, smux);
> + if (!smux->pctl) {
> + dev_err(smux->dev, "could not register simple pinmux driver\n");
> + ret = -EINVAL;
> + goto free;
> + }
> +
> + ret = smux_populate_map(smux);
> + if (ret < 0)
> + goto free;
> +
> + ret = pinmux_register_mappings(smux->maps.ma,
> + smux->maps.max + 1);
> + if (ret < 0)
> + goto free;
> +
> + dev_info(smux->dev, "pins: %i pingroups: %i functions: %i maps: %i\n",
> + smux->pins.max + 1, smux->ngroups,
> + smux->nfuncs, smux->maps.max + 1);
> +
> + return 0;
> +
> +free:
> + smux_free_resources(smux);
> +
> + return ret;
> +}
> +
> +static struct of_device_id smux_of_match[];
> +static int __devinit smux_probe(struct platform_device *pdev)
> +{
> + const struct of_device_id *match;
> + const u32 *val;
> + struct resource res;
> + struct smux_device *smux;
> + int len, ret;
> +
> + match = of_match_device(smux_of_match, &pdev->dev);
> + if (!match)
> + return -EINVAL;
> +
> + smux = devm_kzalloc(&pdev->dev, sizeof(*smux), GFP_KERNEL);
> + if (!smux) {
> + dev_err(&pdev->dev, "could not allocate\n");
> + return -ENOMEM;
> + }
> + smux->dev = &pdev->dev;
> +
> + val = of_get_property(pdev->dev.of_node,
> + "pinctrl-simple,register-width", &len);
Is there any reason not use of_property_read_u32 here? It may reduce some code.

> + if (!val || len != 4) {
> + dev_err(smux->dev, "mux register width not specified\n");
> + ret = -EINVAL;
> + goto free;
> + }
> + smux->width = be32_to_cpup(val);
> +
> + val = of_get_property(pdev->dev.of_node,
> + "pinctrl-simple,function-mask", &len);
> + if (!val || len != 4) {
> + dev_err(smux->dev, "function register mask not specified\n");
> + ret = -EINVAL;
> + goto free;
> + }
> + smux->fmask = be32_to_cpup(val);
> + smux->fshift = ffs(smux->fmask) - 1;
> + smux->fmax = smux->fmask >> smux->fshift;
> +
> + val = of_get_property(pdev->dev.of_node,
> + "pinctrl-simple,function-off", &len);
> + if (!val || len != 4) {
> + dev_err(smux->dev, "function off mode not specified\n");
> + ret = -EINVAL;
How about other SoCs not support function off mode?

> + goto free;
> + }
> + smux->foff = be32_to_cpup(val);
> +
> + val = of_get_property(pdev->dev.of_node,
> + "pinctrl-simple,pinconf-mask", &len);
> + if (!val || len != 4) {
> + dev_err(smux->dev, "pinconf mask not specified\n");
> + ret = -EINVAL;
> + goto free;
> + }
> + smux->cmask = be32_to_cpup(val);
> +
> + val = of_get_property(pdev->dev.of_node, "#pinmux-cells", &len);
> + if (!val || len != 4) {
> + dev_err(smux->dev, "#pinmux-cells not specified\n");
> + ret = -EINVAL;
> + goto free;
> + }
> + smux->cells = be32_to_cpup(val);
> +
> + ret = of_address_to_resource(pdev->dev.of_node, 0, &res);
> + if (ret) {
> + dev_err(smux->dev, "could not get resource\n");
> + goto free;
> + }
> +
> + smux->res = devm_request_mem_region(smux->dev, res.start,
> + resource_size(&res), DRIVER_NAME);
> + if (!smux->res) {
> + dev_err(smux->dev, "could not get mem_region\n");
> + ret = -EBUSY;
> + goto free;
> + }
> +
> + smux->size = resource_size(smux->res);
> + smux->base = devm_ioremap(smux->dev, smux->res->start, smux->size);
> + if (!smux->base) {
> + dev_err(smux->dev, "could not ioremap\n");
> + ret = -ENODEV;
> + goto release;
> + }
> +
> + INIT_RADIX_TREE(&smux->pgtree, GFP_KERNEL);
> + INIT_RADIX_TREE(&smux->ftree, GFP_KERNEL);
> + platform_set_drvdata(pdev, smux);
> +
> + switch (smux->width) {
> + case 8:
> + smux->read = smux_readb;
> + smux->write = smux_writeb;
> + break;
> + case 16:
> + smux->read = smux_readw;
> + smux->write = smux_writew;
> + break;
> + case 32:
> + smux->read = smux_readl;
> + smux->write = smux_writel;
> + break;
> + default:
> + break;
> + }
> +
> + ret = smux_register(smux);
> + if (ret < 0) {
> + dev_err(smux->dev, "could not add mux registers: %i\n", ret);
> + goto iounmap;
> + }
> +
> + return 0;
> +
> +iounmap:
> + devm_iounmap(smux->dev, smux->base);
> +release:
> + devm_release_mem_region(smux->dev,
> + smux->res->start, resource_size(smux->res));
> +free:
> + devm_kfree(smux->dev, smux);
> +
For devm_* routines, do you still need this error checking?
IIRC, the resource will be automatically released if probe failed.

> + return ret;
> +}
> +
> +static int __devexit smux_remove(struct platform_device *pdev)
> +{
> + struct smux_device *smux = platform_get_drvdata(pdev);
> +
> + if (!smux)
> + return 0;
> +
> + smux_free_resources(smux);
> + devm_iounmap(smux->dev, smux->base);
> + devm_release_mem_region(smux->dev,
> + smux->res->start, resource_size(smux->res));
Ditto.

> + platform_set_drvdata(pdev, NULL);
> + devm_kfree(smux->dev, smux);
> +
> + return 0;
> +}
> +
> +static struct of_device_id smux_of_match[] __devinitdata = {
> + { .compatible = DRIVER_NAME, },
> + { .compatible = "ti,omap2420-pinmux", },
> + { .compatible = "ti,omap2430-pinmux", },
> + { .compatible = "ti,omap3-pinmux", },
> + { .compatible = "ti,omap4-pinmux", },
> + { },
> +};
> +MODULE_DEVICE_TABLE(of, smux_of_match);
> +
> +static struct platform_driver smux_driver = {
> + .probe = smux_probe,
> + .remove = __devexit_p(smux_remove),
> + .driver = {
> + .owner = THIS_MODULE,
> + .name = DRIVER_NAME,
> + .of_match_table = smux_of_match,
> + },
> +};
> +
> +module_platform_driver(smux_driver);
> +
> +MODULE_AUTHOR("Tony Lindgren <tony@atomide.com>");
> +MODULE_DESCRIPTION("Simple device tree pinctrl driver");
> +MODULE_LICENSE("GPL");
>

Regards
Dong Aisheng