]> git.ipfire.org Git - thirdparty/kernel/stable.git/commitdiff
pinctrl: stm32: Support I/O synchronization parameters
authorAntonio Borneo <antonio.borneo@foss.st.com>
Thu, 23 Oct 2025 13:26:57 +0000 (15:26 +0200)
committerLinus Walleij <linus.walleij@linaro.org>
Tue, 28 Oct 2025 09:43:01 +0000 (10:43 +0100)
Devices in the stm32mp2xx family include an I/O synchronization
block on each pin that is used to fine tune and improve the I/O
timing margins of high speed synchronous interfaces.
It can be configured to provide independently for each pin:
- skew rate on input direction or latch delay on output direction;
- inversion of clock signals or re-sampling of data signals.

Add support for the generic properties:
- skew-delay-input-ps;
- skew-delay-output-ps.

Add support for the property 'st,io-sync' to configure clock
inversion or data re-sampling mode.

Show the new parameters on debugfs pinconf-pins.

Enable it for the stm32mp257 pinctrl driver.

Co-developed-by: Valentin Caron <valentin.caron@foss.st.com>
Signed-off-by: Valentin Caron <valentin.caron@foss.st.com>
Co-developed-by: Fabien Dessenne <fabien.dessenne@foss.st.com>
Signed-off-by: Fabien Dessenne <fabien.dessenne@foss.st.com>
Signed-off-by: Antonio Borneo <antonio.borneo@foss.st.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
drivers/pinctrl/stm32/pinctrl-stm32.c
drivers/pinctrl/stm32/pinctrl-stm32.h
drivers/pinctrl/stm32/pinctrl-stm32mp257.c

index ac64cb7f86d74ec186f90ea50bf67a8f4fb6d005..5f8829fdd9851779c5aa97c981b0f1f21d1d14c2 100644 (file)
 #define STM32_GPIO_AFRL                0x20
 #define STM32_GPIO_AFRH                0x24
 #define STM32_GPIO_SECCFGR     0x30
+#define STM32_GPIO_DELAYRL     0x40
+#define STM32_GPIO_ADVCFGRL    0x48
 #define STM32_GPIO_CIDCFGR(x)  (0x50 + (0x8 * (x)))
 #define STM32_GPIO_SEMCR(x)    (0x54 + (0x8 * (x)))
 
+/* Unitary delay for STM32_GPIO_DELAYRL */
+#define STM32_GPIO_DELAYRL_PS  250
+
+#define STM32_GPIO_ADVCFGR_DLYPATH_MASK                BIT(0)
+#define STM32_GPIO_ADVCFGR_DE_MASK             BIT(1)
+#define STM32_GPIO_ADVCFGR_INVCLK_MASK         BIT(2)
+#define STM32_GPIO_ADVCFGR_RET_MASK            BIT(3)
+#define STM32_GPIO_ADVCFGR_IO_SYNC_MASK                \
+       (STM32_GPIO_ADVCFGR_DE_MASK             \
+        | STM32_GPIO_ADVCFGR_INVCLK_MASK       \
+        | STM32_GPIO_ADVCFGR_RET_MASK)
+
 #define STM32_GPIO_CIDCFGR_CFEN                BIT(0)
 #define STM32_GPIO_CIDCFGR_SEMEN       BIT(1)
 #define STM32_GPIO_CIDCFGR_SCID_MASK   GENMASK(5, 4)
@@ -67,6 +81,9 @@
 
 #define SYSCFG_IRQMUX_MASK GENMASK(3, 0)
 
+/* Vendor specific pin configuration */
+#define STM32_GPIO_PIN_CONFIG_IO_SYNC  (PIN_CONFIG_END + 1)
+
 #define gpio_range_to_bank(chip) \
                container_of(chip, struct stm32_gpio_bank, range)
 
@@ -82,6 +99,32 @@ static const char * const stm32_gpio_functions[] = {
        "reserved",
 };
 
+static const char * const stm32_gpio_io_sync[] = {
+       "pass-through",
+       "clock inverted",
+       "data on rising edge",
+       "data on falling edge",
+       "data on both edges",
+};
+
+static u8 io_sync_2_advcfgr[] = {
+       /* data or clock GPIO pass-through */
+       [0] = 0,
+       /* clock GPIO inverted */
+       [1] = STM32_GPIO_ADVCFGR_INVCLK_MASK,
+       /* data GPIO re-sampled on clock rising edge */
+       [2] = STM32_GPIO_ADVCFGR_RET_MASK,
+       /* data GPIO re-sampled on clock falling edge */
+       [3] = STM32_GPIO_ADVCFGR_RET_MASK | STM32_GPIO_ADVCFGR_INVCLK_MASK,
+       /* data GPIO re-sampled on both clock edges */
+       [4] = STM32_GPIO_ADVCFGR_RET_MASK | STM32_GPIO_ADVCFGR_DE_MASK,
+};
+
+static const struct pinconf_generic_params stm32_gpio_bindings[] = {
+       {"st,io-sync", STM32_GPIO_PIN_CONFIG_IO_SYNC, 0,
+        stm32_gpio_io_sync, ARRAY_SIZE(stm32_gpio_io_sync)},
+};
+
 struct stm32_pinctrl_group {
        const char *name;
        unsigned long config;
@@ -95,6 +138,8 @@ struct stm32_pin_backup {
        unsigned int speed:2;
        unsigned int drive:1;
        unsigned int value:1;
+       unsigned int advcfg:4;
+       unsigned int skew_delay:4;
 };
 
 struct stm32_gpio_bank {
@@ -110,6 +155,7 @@ struct stm32_gpio_bank {
        struct stm32_pin_backup pin_backup[STM32_GPIO_PINS_PER_BANK];
        u8 irq_type[STM32_GPIO_PINS_PER_BANK];
        bool secure_control;
+       bool io_sync_control;
        bool rif_control;
 };
 
@@ -201,6 +247,21 @@ static void stm32_gpio_backup_bias(struct stm32_gpio_bank *bank, u32 offset,
        bank->pin_backup[offset].bias = bias;
 }
 
+static void stm32_gpio_backup_advcfg(struct stm32_gpio_bank *bank, u32 offset, u32 mask, u32 value)
+{
+       u32 val;
+
+       val = bank->pin_backup[offset].advcfg;
+       val &= ~mask;
+       val |= value & mask;
+       bank->pin_backup[offset].advcfg = val;
+}
+
+static void stm32_gpio_backup_skew_delay(struct stm32_gpio_bank *bank, u32 offset, u32 delay)
+{
+       bank->pin_backup[offset].skew_delay = delay;
+}
+
 /* RIF functions */
 
 static bool stm32_gpio_rif_valid(struct stm32_gpio_bank *bank, unsigned int gpio_nr)
@@ -1145,6 +1206,155 @@ static u32 stm32_pconf_get_bias(struct stm32_gpio_bank *bank,
        return (val >> (offset * 2));
 }
 
+static void
+stm32_pconf_set_advcfgr_nolock(struct stm32_gpio_bank *bank, int offset, u32 mask, u32 value)
+{
+       int advcfgr_offset = STM32_GPIO_ADVCFGRL + (offset / 8) * 4;
+       int advcfgr_shift = (offset % 8) * 4;
+       u32 val;
+
+       val = readl_relaxed(bank->base + advcfgr_offset);
+       val &= ~(mask << advcfgr_shift);
+       val |= (value & mask) << advcfgr_shift;
+       writel_relaxed(val, bank->base + advcfgr_offset);
+
+       stm32_gpio_backup_advcfg(bank, offset, mask, value);
+}
+
+static int stm32_pconf_set_advcfgr(struct stm32_gpio_bank *bank, int offset, u32 mask, u32 value)
+{
+       struct stm32_pinctrl *pctl = dev_get_drvdata(bank->gpio_chip.parent);
+       unsigned long flags;
+       int err = 0;
+
+       if (!bank->io_sync_control)
+               return -ENOTSUPP;
+
+       spin_lock_irqsave(&bank->lock, flags);
+
+       if (pctl->hwlock) {
+               err = hwspin_lock_timeout_in_atomic(pctl->hwlock, HWSPNLCK_TIMEOUT);
+               if (err) {
+                       dev_err(pctl->dev, "Can't get hwspinlock\n");
+                       goto unlock;
+               }
+       }
+
+       stm32_pconf_set_advcfgr_nolock(bank, offset, mask, value);
+
+       if (pctl->hwlock)
+               hwspin_unlock_in_atomic(pctl->hwlock);
+
+unlock:
+       spin_unlock_irqrestore(&bank->lock, flags);
+
+       return err;
+}
+
+static u32 stm32_pconf_get_advcfgr(struct stm32_gpio_bank *bank, int offset, u32 mask)
+{
+       int advcfgr_offset = STM32_GPIO_ADVCFGRL + (offset / 8) * 4;
+       int advcfgr_shift = (offset % 8) * 4;
+       u32 val;
+
+       if (!bank->io_sync_control)
+               return 0;
+
+       val = readl_relaxed(bank->base + advcfgr_offset);
+       val >>= advcfgr_shift;
+
+       return val & mask;
+}
+
+static int stm32_pconf_set_io_sync(struct stm32_gpio_bank *bank, int offset, u32 io_sync)
+{
+       if (io_sync >= ARRAY_SIZE(io_sync_2_advcfgr))
+               return -EINVAL;
+
+       return stm32_pconf_set_advcfgr(bank, offset, STM32_GPIO_ADVCFGR_IO_SYNC_MASK,
+               io_sync_2_advcfgr[io_sync]);
+}
+
+static const char *stm32_pconf_get_io_sync_str(struct stm32_gpio_bank *bank, int offset)
+{
+       u32 io_sync = stm32_pconf_get_advcfgr(bank, offset, STM32_GPIO_ADVCFGR_IO_SYNC_MASK);
+
+       if (io_sync & STM32_GPIO_ADVCFGR_RET_MASK) {
+               if (io_sync & STM32_GPIO_ADVCFGR_DE_MASK)
+                       return "data GPIO re-sampled on both clock edges";
+
+               if (io_sync & STM32_GPIO_ADVCFGR_INVCLK_MASK)
+                       return "data GPIO re-sampled on clock falling edge";
+
+               return "data GPIO re-sampled on clock rising edge";
+       }
+
+       if (io_sync & STM32_GPIO_ADVCFGR_INVCLK_MASK)
+               return "clock GPIO inverted";
+
+       return NULL;
+}
+
+static int
+stm32_pconf_set_skew_delay(struct stm32_gpio_bank *bank, int offset, u32 delay, bool is_dir_input)
+{
+       struct stm32_pinctrl *pctl = dev_get_drvdata(bank->gpio_chip.parent);
+       int delay_offset = STM32_GPIO_DELAYRL + (offset / 8) * 4;
+       int delay_shift = (offset % 8) * 4;
+       unsigned long flags;
+       int err = 0;
+       u32 val;
+
+       if (!bank->io_sync_control)
+               return -ENOTSUPP;
+
+       spin_lock_irqsave(&bank->lock, flags);
+
+       if (pctl->hwlock) {
+               err = hwspin_lock_timeout_in_atomic(pctl->hwlock, HWSPNLCK_TIMEOUT);
+               if (err) {
+                       dev_err(pctl->dev, "Can't get hwspinlock\n");
+                       goto unlock;
+               }
+       }
+
+       val = readl_relaxed(bank->base + delay_offset);
+       val &= ~GENMASK(delay_shift + 3, delay_shift);
+       val |= (delay << delay_shift);
+       writel_relaxed(val, bank->base + delay_offset);
+
+       stm32_gpio_backup_skew_delay(bank, offset, delay);
+
+       stm32_pconf_set_advcfgr_nolock(bank, offset, STM32_GPIO_ADVCFGR_DLYPATH_MASK,
+                                      is_dir_input ? STM32_GPIO_ADVCFGR_DLYPATH_MASK : 0);
+
+       if (pctl->hwlock)
+               hwspin_unlock_in_atomic(pctl->hwlock);
+
+unlock:
+       spin_unlock_irqrestore(&bank->lock, flags);
+
+       return err;
+}
+
+static u32 stm32_pconf_get_skew_delay_val(struct stm32_gpio_bank *bank, int offset)
+{
+       int delay_offset = STM32_GPIO_DELAYRL + (offset / 8) * 4;
+       int delay_shift = (offset % 8) * 4;
+       u32 val;
+
+       val = readl_relaxed(bank->base + delay_offset);
+       val &= GENMASK(delay_shift + 3, delay_shift);
+
+       return val >> delay_shift;
+}
+
+static const char *stm32_pconf_get_skew_dir_str(struct stm32_gpio_bank *bank, int offset)
+{
+       return stm32_pconf_get_advcfgr(bank, offset, STM32_GPIO_ADVCFGR_DLYPATH_MASK) ?
+               "input" : "output";
+}
+
 static bool stm32_pconf_get(struct stm32_gpio_bank *bank,
        unsigned int offset, bool dir)
 {
@@ -1207,6 +1417,17 @@ static int stm32_pconf_parse_conf(struct pinctrl_dev *pctldev,
                __stm32_gpio_set(bank, offset, arg);
                ret = stm32_pmx_gpio_set_direction(pctldev, range, pin, false);
                break;
+       case PIN_CONFIG_SKEW_DELAY_INPUT_PS:
+               arg /= STM32_GPIO_DELAYRL_PS;
+               ret = stm32_pconf_set_skew_delay(bank, offset, arg, true);
+               break;
+       case PIN_CONFIG_SKEW_DELAY_OUTPUT_PS:
+               arg /= STM32_GPIO_DELAYRL_PS;
+               ret = stm32_pconf_set_skew_delay(bank, offset, arg, false);
+               break;
+       case STM32_GPIO_PIN_CONFIG_IO_SYNC:
+               ret = stm32_pconf_set_io_sync(bank, offset, arg);
+               break;
        default:
                ret = -ENOTSUPP;
        }
@@ -1349,6 +1570,22 @@ static void stm32_pconf_dbg_show(struct pinctrl_dev *pctldev,
        case 3:
                break;
        }
+
+       if (bank->io_sync_control) {
+               const char *io_sync_str, *skew_dir_str;
+               u32 skew_delay;
+
+               io_sync_str = stm32_pconf_get_io_sync_str(bank, offset);
+               skew_dir_str = stm32_pconf_get_skew_dir_str(bank, offset);
+               skew_delay = stm32_pconf_get_skew_delay_val(bank, offset);
+
+               if (io_sync_str)
+                       seq_printf(s, " - IO-sync: %s", io_sync_str);
+
+               if (skew_delay)
+                       seq_printf(s, " - Skew-delay: %u (%u ps) %s", skew_delay,
+                                  skew_delay * STM32_GPIO_DELAYRL_PS, skew_dir_str);
+       }
 }
 
 static const struct pinconf_ops stm32_pconf_ops = {
@@ -1441,6 +1678,7 @@ static int stm32_gpiolib_register_bank(struct stm32_pinctrl *pctl, struct fwnode
        bank->bank_nr = bank_nr;
        bank->bank_ioport_nr = bank_ioport_nr;
        bank->secure_control = pctl->match_data->secure_control;
+       bank->io_sync_control = pctl->match_data->io_sync_control;
        bank->rif_control = pctl->match_data->rif_control;
        spin_lock_init(&bank->lock);
 
@@ -1683,6 +1921,8 @@ int stm32_pctl_probe(struct platform_device *pdev)
        pctl->pctl_desc.confops = &stm32_pconf_ops;
        pctl->pctl_desc.pctlops = &stm32_pctrl_ops;
        pctl->pctl_desc.pmxops = &stm32_pmx_ops;
+       pctl->pctl_desc.num_custom_params = ARRAY_SIZE(stm32_gpio_bindings);
+       pctl->pctl_desc.custom_params = stm32_gpio_bindings;
        pctl->dev = &pdev->dev;
 
        pctl->pctl_dev = devm_pinctrl_register(&pdev->dev, &pctl->pctl_desc,
@@ -1804,6 +2044,21 @@ static int __maybe_unused stm32_pinctrl_restore_gpio_regs(
        if (ret)
                return ret;
 
+       if (bank->io_sync_control) {
+               bool is_input = bank->pin_backup[offset].advcfg & STM32_GPIO_ADVCFGR_DLYPATH_MASK;
+
+               ret = stm32_pconf_set_skew_delay(bank, offset,
+                                                bank->pin_backup[offset].skew_delay,
+                                                is_input);
+               if (ret)
+                       return ret;
+
+               ret = stm32_pconf_set_advcfgr(bank, offset, STM32_GPIO_ADVCFGR_IO_SYNC_MASK,
+                                             bank->pin_backup[offset].advcfg);
+               if (ret)
+                       return ret;
+       }
+
        if (pin_is_irq)
                regmap_field_write(pctl->irqmux[offset], bank->bank_ioport_nr);
 
index b98a4141bf2c0225d239d6e2673f46304c8b21d8..d17cbdbba448262cffc5bcde4ac358f08fa7d134 100644 (file)
@@ -64,6 +64,7 @@ struct stm32_pinctrl_match_data {
        const struct stm32_desc_pin *pins;
        const unsigned int npins;
        bool secure_control;
+       bool io_sync_control;
        bool rif_control;
 };
 
index d226de524bfc1bc10f9a0d402ccda0cbcd91c6eb..6709bddd971861813dcdb5d7cac957e3ff1e48d4 100644 (file)
@@ -2543,6 +2543,7 @@ static const struct stm32_desc_pin stm32mp257_z_pins[] = {
 static struct stm32_pinctrl_match_data stm32mp257_match_data = {
        .pins = stm32mp257_pins,
        .npins = ARRAY_SIZE(stm32mp257_pins),
+       .io_sync_control = true,
        .secure_control = true,
        .rif_control = true,
 };
@@ -2550,6 +2551,7 @@ static struct stm32_pinctrl_match_data stm32mp257_match_data = {
 static struct stm32_pinctrl_match_data stm32mp257_z_match_data = {
        .pins = stm32mp257_z_pins,
        .npins = ARRAY_SIZE(stm32mp257_z_pins),
+       .io_sync_control = true,
        .secure_control = true,
        .rif_control = true,
 };