Re: [DO NOT MERGE v5 23/37] mfd: sm501: Convert platform_data to OF property

Lee Jones
2023-12-07T16:37:06Z

On Tue, 05 Dec 2023, Yoshinori Sato wrote:

> Various parameters of SM501 can be set using platform_data,
> so parameters cannot be passed in the DeviceTree target.
> Expands the parameters set in platform_data so that they can be
> specified using DeviceTree properties.
>
> Signed-off-by: Yoshinori Sato <ysato@users.sourceforge.jp>
> ---
> drivers/mfd/sm501.c | 99 +++++++++++++++++++++++++++++++++++
> drivers/video/fbdev/sm501fb.c | 82 +++++++++++++++++++++++++++++
> 2 files changed, 181 insertions(+)
>
> diff --git a/drivers/mfd/sm501.c b/drivers/mfd/sm501.c
> index 28027982cf69..f0104fdf0f34 100644
> --- a/drivers/mfd/sm501.c
> +++ b/drivers/mfd/sm501.c
> @@ -1370,6 +1370,99 @@ static int sm501_init_dev(struct sm501_devdata *sm)
> return 0;
> }
>
> +static void sm501_of_read_reg_init(struct device_node *np,
> + const char *propname, struct sm501_reg_init *val)
> +{
> + u32 u32_val[2];

Encoding the size of the variable in the variable name is odd.

> +
> + if (!of_property_read_u32_array(np, propname, u32_val, sizeof(u32_val))) {
> + val->set = u32_val[0];
> + val->mask = u32_val[1];

Masks and register values stored as DT properties? This is generally
not permitted. Please seek counsel from the DT maintainers.

> + }
> +}
> +
> +/* Read GPIO I2C configuration */
> +static int sm501_parse_dt_gpio_i2c(struct device *dev, struct sm501_platdata *plat,
> + struct device_node *np)
> +{
> + struct sm501_platdata_gpio_i2c *gpio_i2c_p;
> + struct property *prop;
> + u32 gpio_i2c[5];

Why 5? Please define all magic numbers.

> + const __be32 *p;
> + unsigned int i;
> + u32 i2c_nr;
> +
> + prop = of_find_property(np, "smi,gpio-i2c", NULL);
> + if (!prop)
> + return 0;
> +
> + i2c_nr = of_property_count_u32_elems(np, "smi,gpio-i2c");

Why do you need both of these probing functions? What does
of_property_count_u32_elems() return if smi,gpio-i2c doesn't exist?

> + /* GPIO I2C define 5 words per channel. */
> + if (i2c_nr % 5)
> + return -EINVAL;
> + i2c_nr /= 5;

'\n'

> + plat->gpio_i2c = devm_kzalloc(dev, sizeof(*plat->gpio_i2c) * i2c_nr,
> + GFP_KERNEL);
> + if (!plat->gpio_i2c)
> + return -ENOMEM;
> +
> + plat->gpio_i2c_nr = i2c_nr;
> + gpio_i2c_p = plat->gpio_i2c;

What's the purpose of this intermediary variable?

> +
> + for (; i2c_nr > 0; i2c_nr--) {

You can define 'p' in here, right?

> + for (i = 0; i < ARRAY_SIZE(gpio_i2c); i++) {
> + p = of_prop_next_u32(prop, p, &gpio_i2c[i]);
> + if (!p)
> + return -EINVAL;
> + }
> + gpio_i2c_p->bus_num = gpio_i2c[0];
> + gpio_i2c_p->pin_sda = gpio_i2c[1];
> + gpio_i2c_p->pin_scl = gpio_i2c[2];
> + gpio_i2c_p->udelay = gpio_i2c[3];
> + gpio_i2c_p->timeout = gpio_i2c[4];

I'm not even going to ask. I'll leave this to the DT maintainers.

> + gpio_i2c_p++;
> + }
> + return 0;
> +}
> +
> +/* Build platform_data from OF property */
> +static int sm501_parse_dt(struct sm501_devdata *sm, struct device_node *np)
> +{
> + struct sm501_platdata *plat;
> + u32 u32_val;
> + int ret;
> +
> + plat = devm_kzalloc(sm->dev, sizeof(*plat), GFP_KERNEL);
> + if (!plat)
> + return -ENOMEM;
> +
> + plat->init = devm_kzalloc(sm->dev, sizeof(*plat->init), GFP_KERNEL);

Why not grab all of the memory at once?

Maybe make this 'init' thing a non-pointer.

> + if (!plat->init)
> + return -ENOMEM;
> +
> + if (!of_property_read_u32(np, "smi,devices", &u32_val))
> + plat->init->devices = u32_val;

What happens if you do:

of_property_read_u32(np, "smi,devices", &plat->init->devices);

> + if (!of_property_read_u32(np, "smi,mclk", &u32_val))
> + plat->init->mclk = u32_val;
> + if (!of_property_read_u32(np, "smi,m1xclk", &u32_val))
> + plat->init->m1xclk = u32_val;
> +
> + sm501_of_read_reg_init(np, "smi,misc-timing", &plat->init->misc_timing);
> + sm501_of_read_reg_init(np, "smi,misc-control", &plat->init->misc_control);
> + sm501_of_read_reg_init(np, "smi,gpio-low", &plat->init->gpio_low);
> + sm501_of_read_reg_init(np, "smi,gpio-high", &plat->init->gpio_high);
> +
> + if (IS_ENABLED(CONFIG_MFD_SM501_GPIO) &&
> + (plat->init->devices & SM501_USE_GPIO)) {

That's over-bracketed, right?

plat->init->devices is a bit mask of enable devices stored in DT?

Okay, I think this is going to need a lot of work on the DT side.

Leaving the review here for now.

> + ret = sm501_parse_dt_gpio_i2c(sm->dev, plat, np);
> + if (ret)
> + return ret;
> + }
> + sm->platdata = plat;
> + return 0;
> +}
> +
> static int sm501_plat_probe(struct platform_device *dev)
> {
> struct sm501_devdata *sm;
> @@ -1406,6 +1499,12 @@ static int sm501_plat_probe(struct platform_device *dev)
> goto err_res;
> }
>
> + if (IS_ENABLED(CONFIG_OF) && dev->dev.of_node) {
> + ret = sm501_parse_dt(sm, dev->dev.of_node);
> + if (ret)
> + goto err_res;
> + }
> +
> platform_set_drvdata(dev, sm);
>
> sm->regs = ioremap(sm->io_res->start, resource_size(sm->io_res));
> diff --git a/drivers/video/fbdev/sm501fb.c b/drivers/video/fbdev/sm501fb.c
> index d6fdc1737cd2..d35285819d28 100644
> --- a/drivers/video/fbdev/sm501fb.c
> +++ b/drivers/video/fbdev/sm501fb.c
> @@ -1932,6 +1932,82 @@ static int sm501fb_start_one(struct sm501fb_info *info,
> return 0;
> }
>
> +#if defined(CONFIG_OF)
> +/* parse CRT / panel configuration */
> +static struct sm501_platdata_fbsub *dt_fbsub(struct device *dev,
> + struct device_node *np,
> + const char *name)
> +{
> + struct sm501_platdata_fbsub *fbsub = NULL;
> + struct fb_videomode *def_mode = NULL;
> + struct device_node *child;
> + const void *p_edid;
> + u32 flags = 0;
> + u32 bpp = 0;
> + int len;
> +
> + child = of_get_child_by_name(np, name);
> + if (child == NULL)
> + return NULL;
> +
> + p_edid = of_get_property(child, "edid", &len);
> + if (p_edid && len == EDID_LENGTH) {
> + struct fb_monspecs *specs;
> + u8 *edid;
> +
> + edid = kmemdup(p_edid, EDID_LENGTH, GFP_KERNEL);
> + if (edid) {
> + specs = kzalloc(sizeof(*specs), GFP_KERNEL);
> + if (specs) {
> + fb_edid_to_monspecs(edid, specs);
> + def_mode = specs->modedb;
> + }
> + }
> + kfree(edid);
> + }
> +
> + of_property_read_u32(child, "bpp", &bpp);
> +
> + /* If flags property is obtained, fbsub is returned. */
> + if (!of_property_read_u32(child, "smi,flags", &flags)) {
> + fbsub = devm_kzalloc(dev, sizeof(*fbsub), GFP_KERNEL);
> + if (fbsub) {
> + fbsub->def_mode = def_mode;
> + fbsub->def_bpp = bpp;
> + fbsub->flags = flags;
> + }
> + }
> + return fbsub;
> +}
> +
> +/* Build platform_data from OF property */
> +static struct sm501_platdata_fb *pdata_from_dt(struct device *dev, struct device_node *np)
> +{
> + enum sm501_fb_routing fb_route = SM501_FB_OWN;
> + struct sm501_platdata_fb *pdata = NULL;
> + struct sm501_platdata_fbsub *fb_crt;
> + struct sm501_platdata_fbsub *fb_pnl;
> + unsigned int flags = 0;
> +
> + if (of_property_read_bool(np, "route-crt-panel"))
> + fb_route = SM501_FB_CRT_PANEL;
> + if (of_property_read_bool(np, "swap-fb-endian"))
> + flags = SM501_FBPD_SWAP_FB_ENDIAN;
> + fb_crt = dt_fbsub(dev, np, "crt");
> + fb_pnl = dt_fbsub(dev, np, "panel");
> + if (fb_crt || fb_pnl) {
> + pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
> + if (pdata) {
> + pdata->fb_route = fb_route;
> + pdata->flags = flags;
> + pdata->fb_crt = fb_crt;
> + pdata->fb_pnl = fb_pnl;
> + }
> + }
> + return pdata;
> +}
> +#endif
> +
> static int sm501fb_probe(struct platform_device *pdev)
> {
> struct sm501fb_info *info;
> @@ -1974,6 +2050,12 @@ static int sm501fb_probe(struct platform_device *pdev)
> if (info->edid_data)
> found = 1;
> }
> + /* Get platform data compatible configuration */
> + if (!found) {
> + info->pdata = pdata_from_dt(dev, np);
> + if (info->pdata)
> + found = 1;
> + }
> }
> #endif
> if (!found) {
> --
> 2.39.2
>

--
Lee Jones [李琼斯]