pinctrl: sh-pfc: Validate pinmux tables at runtime when debugging

Perform some basic sanity checks on all built-in pinmux tables when
DEBUG is defined, to help catching bugs early.

For now the following checks are included:
  - Check register and field widths in descriptors for config registers
    with variable-width fields,
  - Check relations between pin groups and functions:
      - All pin functions must refer to existing pin groups,
      - All pin groups must be referred to by a pin function,
      - Warn if a pin group is referred to by multiple pin functions
	(which is OK for backwards-compatibility aliases),
  - Provide suggestions for reducing table sizes: reserved fields of
    more than 3 bits can better be split in smaller subfields, as the
    storage need is proportional to the square of the width of the
    (sub)field,

Note that a dummy non-matching entry is added to the DT match table for
checking r8a7795es1_pinmux_info, as R-Car H3 ES1.0 is matched using
soc_device_match() in r8a7795_pinmux_init(), instead of by the DT match
table.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
This commit is contained in:
Geert Uytterhoeven 2018-12-13 15:48:45 +01:00
parent d92ee9cf8e
commit 6161b39a14

View file

@ -571,6 +571,13 @@ static const struct of_device_id sh_pfc_of_table[] = {
.compatible = "renesas,pfc-r8a7795",
.data = &r8a7795_pinmux_info,
},
#ifdef DEBUG
{
/* For sanity checks only (nothing matches against this) */
.compatible = "renesas,pfc-r8a77950", /* R-Car H3 ES1.0 */
.data = &r8a7795es1_pinmux_info,
},
#endif /* DEBUG */
#endif
#ifdef CONFIG_PINCTRL_PFC_R8A7796
{
@ -709,6 +716,122 @@ static int sh_pfc_suspend_init(struct sh_pfc *pfc) { return 0; }
#define DEV_PM_OPS NULL
#endif /* CONFIG_PM_SLEEP && CONFIG_ARM_PSCI_FW */
#ifdef DEBUG
static bool is0s(const u16 *enum_ids, unsigned int n)
{
unsigned int i;
for (i = 0; i < n; i++)
if (enum_ids[i])
return false;
return true;
}
static unsigned int sh_pfc_errors;
static unsigned int sh_pfc_warnings;
static void sh_pfc_check_cfg_reg(const char *drvname,
const struct pinmux_cfg_reg *cfg_reg)
{
unsigned int i, n, rw, fw;
if (cfg_reg->field_width) {
/* Checked at build time */
return;
}
for (i = 0, n = 0, rw = 0; (fw = cfg_reg->var_field_width[i]); i++) {
if (fw > 3 && is0s(&cfg_reg->enum_ids[n], 1 << fw)) {
pr_warn("%s: reg 0x%x: reserved field [%u:%u] can be split to reduce table size\n",
drvname, cfg_reg->reg, rw, rw + fw - 1);
sh_pfc_warnings++;
}
n += 1 << fw;
rw += fw;
}
if (rw != cfg_reg->reg_width) {
pr_err("%s: reg 0x%x: var_field_width declares %u instead of %u bits\n",
drvname, cfg_reg->reg, rw, cfg_reg->reg_width);
sh_pfc_errors++;
}
}
static void sh_pfc_check_info(const struct sh_pfc_soc_info *info)
{
const struct sh_pfc_function *func;
const char *drvname = info->name;
unsigned int *refcnts;
unsigned int i, j, k;
pr_info("Checking %s\n", drvname);
/* Check groups and functions */
refcnts = kcalloc(info->nr_groups, sizeof(*refcnts), GFP_KERNEL);
if (!refcnts)
return;
for (i = 0; i < info->nr_functions; i++) {
func = &info->functions[i];
for (j = 0; j < func->nr_groups; j++) {
for (k = 0; k < info->nr_groups; k++) {
if (!strcmp(func->groups[j],
info->groups[k].name)) {
refcnts[k]++;
break;
}
}
if (k == info->nr_groups) {
pr_err("%s: function %s: group %s not found\n",
drvname, func->name, func->groups[j]);
sh_pfc_errors++;
}
}
}
for (i = 0; i < info->nr_groups; i++) {
if (!refcnts[i]) {
pr_err("%s: orphan group %s\n", drvname,
info->groups[i].name);
sh_pfc_errors++;
} else if (refcnts[i] > 1) {
pr_err("%s: group %s referred by %u functions\n",
drvname, info->groups[i].name, refcnts[i]);
sh_pfc_warnings++;
}
}
kfree(refcnts);
/* Check config register descriptions */
for (i = 0; info->cfg_regs && info->cfg_regs[i].reg; i++)
sh_pfc_check_cfg_reg(drvname, &info->cfg_regs[i]);
}
static void sh_pfc_check_driver(const struct platform_driver *pdrv)
{
unsigned int i;
pr_warn("Checking builtin pinmux tables\n");
for (i = 0; pdrv->id_table[i].name[0]; i++)
sh_pfc_check_info((void *)pdrv->id_table[i].driver_data);
#ifdef CONFIG_OF
for (i = 0; pdrv->driver.of_match_table[i].compatible[0]; i++)
sh_pfc_check_info(pdrv->driver.of_match_table[i].data);
#endif
pr_warn("Detected %u errors and %u warnings\n", sh_pfc_errors,
sh_pfc_warnings);
}
#else /* !DEBUG */
static inline void sh_pfc_check_driver(struct platform_driver *pdrv) {}
#endif /* !DEBUG */
static int sh_pfc_probe(struct platform_device *pdev)
{
#ifdef CONFIG_OF
@ -840,6 +963,7 @@ static struct platform_driver sh_pfc_driver = {
static int __init sh_pfc_init(void)
{
sh_pfc_check_driver(&sh_pfc_driver);
return platform_driver_register(&sh_pfc_driver);
}
postcore_initcall(sh_pfc_init);