Thread (15 messages) 15 messages, 4 authors, 2021-11-10

Re: [PATCH v2 2/5] pinctrl: renesas: pinctrl-rzg2l: Add helper functions to read/write pin config

From: Geert Uytterhoeven <geert@linux-m68k.org>
Date: 2021-11-08 15:33:07
Also in: linux-gpio, linux-renesas-soc, lkml

Hi Prabhakar,

On Fri, Oct 29, 2021 at 2:44 PM Lad Prabhakar
[off-list ref] wrote:
Add helper functions to read/read modify write pin config.

Switch to use helper functions for pins supporting PIN_CONFIG_INPUT_ENABLE
capabilities.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Biju Das <biju.das.jz@bp.renesas.com>
Thanks for your patch!
quoted hunk ↗ jump to hunk
--- a/drivers/pinctrl/renesas/pinctrl-rzg2l.c
+++ b/drivers/pinctrl/renesas/pinctrl-rzg2l.c
@@ -91,6 +91,8 @@
 #define SD_CH(n)               (0x3000 + (n) * 4)
 #define QSPI                   (0x3008)

+#define PORT_PIN_CFG_OFFSET    0x80
This definition belongs in [PATCH v2 5/5].
quoted hunk ↗ jump to hunk
+
 #define PVDD_1800              1       /* I/O domain voltage <= 1.8V */
 #define PVDD_3300              0       /* I/O domain voltage >= 3.3V */
@@ -424,6 +426,52 @@ static int rzg2l_dt_node_to_map(struct pinctrl_dev *pctldev,
        return ret;
 }

+static u32 rzg2l_read_pin_config(struct rzg2l_pinctrl *pctrl, bool port_pin,
+                                u32 offset, u8 bit, u32 mask)
+{
+       void __iomem *addr = pctrl->base + offset;
+       unsigned long flags;
+       u32 reg;
+
+       if (port_pin)
+               addr += PORT_PIN_CFG_OFFSET;
I'm wondering if it would be better to handle this in the caller,
by passing an adjusted offset?
Same for rzg2l_rmw_pin_config().
+
+       /* handle _L/_H for 32-bit register read/write */
+       if (bit >= 4) {
+               bit -= 4;
+               addr += 4;
+       }
+
+       spin_lock_irqsave(&pctrl->lock, flags);
+       reg = readl(addr) & (mask << (bit * 8));
The masking is not needed here, as it is done below.
+       spin_unlock_irqrestore(&pctrl->lock, flags);
I still think you don't need that spinlock here, as reading a MMIO
register is an atomic operation.

(/me fixes drivers/pinctrl/renesas/pinctrl.c you referred to before)
+       reg = (reg >> (bit * 8)) & mask;
+
+       return reg;
return (reg >> (bit * 8)) & mask;
+}
quoted hunk ↗ jump to hunk
@@ -432,10 +480,11 @@ static int rzg2l_pinctrl_pinconf_get(struct pinctrl_dev *pctldev,
        enum pin_config_param param = pinconf_to_config_param(*config);
        const struct pinctrl_pin_desc *pin = &pctrl->desc.pins[_pin];
        unsigned int *pin_data = pin->drv_data;
+       bool port_pin = false;
Do you really need this?
quoted hunk ↗ jump to hunk
        unsigned int arg = 0;
        unsigned long flags;
        void __iomem *addr;
-       u32 port = 0, reg;
+       u32 port = 0;
        u32 cfg = 0;
        u8 bit = 0;
@@ -452,17 +501,8 @@ static int rzg2l_pinctrl_pinconf_get(struct pinctrl_dev *pctldev,
        case PIN_CONFIG_INPUT_ENABLE:
                if (!(cfg & PIN_CFG_IEN))
                        return -EINVAL;
-               spin_lock_irqsave(&pctrl->lock, flags);
-               /* handle _L/_H for 32-bit register read/write */
-               addr = pctrl->base + IEN(port);
-               if (bit >= 4) {
-                       bit -= 4;
-                       addr += 4;
-               }

-               reg = readl(addr) & (IEN_MASK << (bit * 8));
-               arg = (reg >> (bit * 8)) & 0x1;
-               spin_unlock_irqrestore(&pctrl->lock, flags);
+               arg = rzg2l_read_pin_config(pctrl, port_pin, IEN(port), bit, IEN_MASK);
port_pin is always false here, as PIN_CFG_IEN is only ever set for
dedicated pins.

Same comments for rzg2l_pinctrl_pinconf_set().

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds
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