Thread (9 messages) 9 messages, 3 authors, 2021-06-14

Re: [PATCH 3/5] i2c: riic: Add RZ/G2L support

From: Geert Uytterhoeven <geert@linux-m68k.org>
Date: 2021-06-14 12:38:40
Also in: linux-renesas-soc

Hi Biju,

On Fri, Jun 11, 2021 at 6:56 PM Biju Das [off-list ref] wrote:
RZ/G2L i2c controller is compatible with RZ/A i2c controller.
By default IP is in reset state, so need to perform release
reset before accessing any register.

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Thanks for your patch!
quoted hunk ↗ jump to hunk
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -941,6 +941,7 @@ config I2C_QUP
 config I2C_RIIC
        tristate "Renesas RIIC adapter"
        depends on ARCH_RENESAS || COMPILE_TEST
+       select RESET_CONTROLLER
if ARCH_R9A07G044?
quoted hunk ↗ jump to hunk
--- a/drivers/i2c/busses/i2c-riic.c
+++ b/drivers/i2c/busses/i2c-riic.c
_kzalloc(&pdev->dev, sizeof(*riic), GFP_KERNEL);
quoted hunk ↗ jump to hunk
        if (!riic)
@@ -412,6 +421,17 @@ static int riic_i2c_probe(struct platform_device *pdev)
                return PTR_ERR(riic->clk);
        }

+       type = (enum riic_type)of_device_get_match_data(&pdev->dev);
+       if (type == RIIC_RZ_G2L) {
+               rstc = devm_reset_control_get(&pdev->dev, NULL);
+               if (IS_ERR(rstc)) {
+                       dev_err(&pdev->dev, "Error: missing reset ctrl\n");
+                       return PTR_ERR(rstc);
+               }
+
+               reset_control_deassert(rstc);
Just wondering: does it harm if the driver is unloaded or unbounded,
and rebound while the I2C controller is not in reset state?
quoted hunk ↗ jump to hunk
+       }
+
        for (i = 0; i < ARRAY_SIZE(riic_irqs); i++) {
                res = platform_get_resource(pdev, IORESOURCE_IRQ, riic_irqs[i].res_num);
                if (!res)
@@ -472,6 +492,7 @@ static int riic_i2c_remove(struct platform_device *pdev)
 }

 static const struct of_device_id riic_i2c_dt_ids[] = {
+       { .compatible = "renesas,riic-r9a07g044", .data = (void *)RIIC_RZ_G2L },
        { .compatible = "renesas,riic-rz" },
Please fill in .data, to avoid relying implicitly on RIIC_RZ_A being zero.
        { /* Sentinel */ },
 };
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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