Re: [PATCH 3/3] i3c: master: svc: Add Amlogic A9 glue layer
From: Junyi Zhao
Date: Wed Oct 21 2026 - 01:18:13 EST
Hi Neil，
thanks for your review.
On 2026/10/19 15:40, Neil Armstrong wrote:
On 10/19/26 07:34, Junyi Zhao via B4 Relay wrote:
From: Junyi Zhao <junyi.zhao@xxxxxxxxxxx>
Add support for the Amlogic A9 implementation of the Silvaco
SVC I3C controller.
The glue layer provides Amlogic-specific operations and resource
handling while reusing the common SVC I3C core driver.
Add a corresponding MAINTAINERS entry for the Amlogic I3C
controller.
Signed-off-by: Junyi Zhao <junyi.zhao@xxxxxxxxxxx>
---
MAINTAINERS | 6 +
drivers/i3c/master/svc/Kconfig | 7 +
drivers/i3c/master/svc/Makefile | 1 +
drivers/i3c/master/svc/i3c-amlogic.c | 250 +++++++++++++++++++++++++ ++++++++++
4 files changed, 264 insertions(+)
diff --git a/MAINTAINERS b/MAINTAINERS
index dffc63af2..478979446 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1398,6 +1398,12 @@ F: Documentation/userspace-api/media/v4l/ metafmt-c3-isp.rst
F: drivers/media/platform/amlogic/c3/isp/
F: include/uapi/linux/media/amlogic/
+AMLOGIC I3C DRIVER
+M: Junyi Zhao <junyi.zhao@xxxxxxxxxxx>
+S: Maintained
+F: Documentation/devicetree/bindings/i3c/amlogic,i3c-a9.yaml
+F: drivers/i3c/master/svc/i3c-amlogic.c
+
AMLOGIC MIPI ADAPTER DRIVER
M: Keke Li <keke.li@xxxxxxxxxxx>
L: linux-media@xxxxxxxxxxxxxxx
diff --git a/drivers/i3c/master/svc/Kconfig b/drivers/i3c/master/svc/ Kconfig
index 14fa1e542..df3528bc1 100644
--- a/drivers/i3c/master/svc/Kconfig
+++ b/drivers/i3c/master/svc/Kconfig
@@ -18,4 +18,11 @@ config I3C_SILVACO
compatible strings such as "silvaco,i3c-master-v1" and
"nuvoton,npcm845-i3c".
+config I3C_AMLOGIC
+ tristate "Amlogic I3C support"
+ default y
+ help
+ This selects the Amlogic SoC glue layer support for
+ the Silvaco device driver. This driver is used for A9, C5 SoCs.
+
endif # SVC_I3C
diff --git a/drivers/i3c/master/svc/Makefile b/drivers/i3c/master/svc/ Makefile
index cf18c5da6..695863d1f 100644
--- a/drivers/i3c/master/svc/Makefile
+++ b/drivers/i3c/master/svc/Makefile
@@ -3,3 +3,4 @@
obj-$(CONFIG_SVC_I3C) += i3c-main.o
obj-$(CONFIG_I3C_SILVACO) += i3c-silvaco.o
+obj-$(CONFIG_I3C_AMLOGIC) += i3c-amlogic.o
diff --git a/drivers/i3c/master/svc/i3c-amlogic.c b/drivers/i3c/ master/svc/i3c-amlogic.c
new file mode 100644
index 000000000..82300d6ae
--- /dev/null
+++ b/drivers/i3c/master/svc/i3c-amlogic.c
@@ -0,0 +1,250 @@
+// SPDX-License-Identifier: (GPL-2.0-only OR MIT)
+/*
+ * Copyright (C) 2026 Amlogic, Inc. All rights reserved
+ */
+#include "i3c-main.h"
+#include <linux/math64.h>
+
+/* Amlogic specific registers */
+#define I3C_BG_RD_ADDR 0x200
+#define I3C_BG_WR_ADDR 0x204
+#define I3C_BG_WR_CTRL 0x208
+#define I3C_BG_R_TT_LEN 0x20c
+#define I3C_BG_X_CNT 0x210
+#define I3C_BUS_MON_CTRL 0x214
+#define I3C_BUS_MON_ADDR 0x218
+#define I3C_BUS_MON_DATA 0x21c
+#define I3C_BUS_MON_DATA_MAK 0x220
+#define I3C_CLK_SLOW_DIV_CTRL 0x224
+#define I3C_BG_R_WCNT_CLR 0x228
+#define I3C_DEBUG_MODIFY 0x22c
+
+#define I3C_AO_CLK_SLOW_DIV_CTRL 0x300
+#define I3C_AO_FCLK_DIV_CTRL 0x304
+#define I3C_AO_FCLK_DIV_MASK GENMASK(7, 0)
+#define I3C_AO_FCLK_DIV_EN BIT(8)
+#define I3C_AO_FCLK_EN BIT(9)
+#define I3C_AO_DEBUG_MODIFY 0x308
+
+#define I3C_DEFAULT_FCLK_RATE 25000000UL
+
+struct amlogic_i3c_priv {
+ int num_clks;
+ struct clk_bulk_data *clks;
+};
+
+struct amlogic_i3c_drvdata {
+ int (*fclk_rate_init)(struct svc_i3c_master *master,
+ struct clk *fclk, unsigned long rate);
+};
+
+static int default_i3c_fclk_rate_init(struct svc_i3c_master *master,
+ struct clk *fclk, unsigned long rate)
+{
+ int err;
+
+ err = clk_set_rate(fclk, rate);
+ if (err)
+ return dev_err_probe(master->dev, err,
+ "setting fast clock rate failed\n");
+
+ return 0;
+}
+
+static int ao_i3c_fclk_rate_init(struct svc_i3c_master *master,
+ struct clk *fclk, unsigned long rate)
+{
+ unsigned int div_cnt, reg_val;
+ unsigned long fin_freq = clk_get_rate(fclk);
+
+ if (!fin_freq)
+ return dev_err_probe(master->dev, -EINVAL,
+ "can't get I3C fast clock rate\n");
+
+ div_cnt = div64_u64(fin_freq, rate);
+ if (!div_cnt || div_cnt > I3C_AO_FCLK_DIV_MASK)
+ return dev_err_probe(master->dev, -EINVAL,
+ "requested fast clock frequency too low\n");
+
+ reg_val = I3C_AO_FCLK_DIV_EN | I3C_AO_FCLK_EN | (div_cnt - 1);
+ writel(reg_val, master->regs + I3C_AO_FCLK_DIV_CTRL);
+
+ return 0;
+}
You could also create a clock divider, register it and use a common clk_set_rate()
for both setups.
will do.
Neil
+
+static int amlogic_i3c_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ const struct amlogic_i3c_drvdata *data;
+ struct svc_i3c_master *master;
+ struct amlogic_i3c_priv *priv;
+ struct clk *fclk;
+ int ret, i;
+
+ master = svc_i3c_master_alloc(dev);
+ if (!master)
+ return -ENOMEM;
+
+ priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ master->drvdata = of_device_get_match_data(dev);
+ if (!master->drvdata)
+ return -EINVAL;
+
+ data = master->drvdata->bsp_data;
+ if (!data)
+ return -EINVAL;
+
+ master->regs = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(master->regs))
+ return PTR_ERR(master->regs);
+
+ master->irq = platform_get_irq(pdev, 0);
+ if (master->irq < 0)
+ return master->irq;
+
+ priv->num_clks = devm_clk_bulk_get_all(dev, &priv->clks);
+ if (priv->num_clks < 0)
+ return dev_err_probe(dev, -EINVAL, "can't get I3C clocks\n");
+
+ for (i = 0; i < priv->num_clks; i++) {
+ if (!strcmp(priv->clks[i].id, "fast_clk"))
+ break;
+ }
+
+ if (i == priv->num_clks)
+ return dev_err_probe(dev, -EINVAL,
+ "can't get I3C peripheral clock\n");
+
+ if (IS_ERR(priv->clks[i].clk))
+ return PTR_ERR(priv->clks[i].clk);
+ fclk = priv->clks[i].clk;
+
+ ret = clk_bulk_prepare_enable(priv->num_clks, priv->clks);
+ if (ret)
+ return dev_err_probe(dev, ret, "can't enable I3C clocks\n");
+
+ master->dev = dev;
+ master->bsp_priv = priv;
+ ret = data->fclk_rate_init(master, fclk, I3C_DEFAULT_FCLK_RATE);
+ if (ret)
+ goto err_disable_clks;
+ master->fclk_rate = I3C_DEFAULT_FCLK_RATE;
+
+ pm_runtime_set_autosuspend_delay(dev, SVC_I3C_PM_TIMEOUT_MS);
+ pm_runtime_use_autosuspend(dev);
+ pm_runtime_get_noresume(dev);
+ pm_runtime_set_active(dev);
+ pm_runtime_enable(dev);
+
+ ret = svc_i3c_master_probe(pdev, master);
+ if (ret)
+ goto rpm_disable;
+
+ platform_set_drvdata(pdev, master);
+ pm_runtime_put_autosuspend(dev);
+
+ return 0;
+
+rpm_disable:
+ pm_runtime_dont_use_autosuspend(dev);
+ pm_runtime_put_noidle(dev);
+ pm_runtime_disable(dev);
+ pm_runtime_set_suspended(dev);
+
+err_disable_clks:
+ clk_bulk_disable_unprepare(priv->num_clks, priv->clks);
+
+ return ret;
+}
+
+static void amlogic_i3c_remove(struct platform_device *pdev)
+{
+ struct svc_i3c_master *master = platform_get_drvdata(pdev);
+
+ svc_i3c_master_remove(master);
+
+ pm_runtime_dont_use_autosuspend(&pdev->dev);
+ pm_runtime_disable(&pdev->dev);
+}
+
+static int __maybe_unused amlogic_i3c_runtime_suspend(struct device *dev)
+{
+ struct svc_i3c_master *master = dev_get_drvdata(dev);
+ struct amlogic_i3c_priv *priv = master->bsp_priv;
+
+ svc_i3c_save_regs(master);
+ clk_bulk_disable_unprepare(priv->num_clks, priv->clks);
+ pinctrl_pm_select_sleep_state(dev);
+
+ return 0;
+}
+
+static int __maybe_unused amlogic_i3c_runtime_resume(struct device *dev)
+{
+ struct svc_i3c_master *master = dev_get_drvdata(dev);
+ struct amlogic_i3c_priv *priv = master->bsp_priv;
+ int ret;
+
+ pinctrl_pm_select_default_state(dev);
+ ret = clk_bulk_prepare_enable(priv->num_clks, priv->clks);
+ if (ret)
+ return ret;
+
+ svc_i3c_restore_regs(master);
+
+ return 0;
+}
+
+static const struct dev_pm_ops amlogic_i3c_pm_ops = {
+ SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
+ pm_runtime_force_resume)
+ SET_RUNTIME_PM_OPS(amlogic_i3c_runtime_suspend,
+ amlogic_i3c_runtime_resume, NULL)
+};
+
+static const struct amlogic_i3c_drvdata amlogic_i3c_data = {
+ .fclk_rate_init = default_i3c_fclk_rate_init,
+};
+
+static const struct amlogic_i3c_drvdata amlogic_i3c_ao_data = {
+ .fclk_rate_init = ao_i3c_fclk_rate_init,
+};
+
+static const struct svc_i3c_drvdata amlogic_a9_drvdata = {
+ .quirks = SVC_I3C_QUIRK_FIFO_EMPTY |
+ SVC_I3C_QUIRK_FALSE_SLVSTART |
+ SVC_I3C_QUIRK_DAA_CORRUPT,
+ .bsp_data = &amlogic_i3c_data,
+};
+
+static const struct svc_i3c_drvdata amlogic_a9_ao_drvdata = {
+ .quirks = SVC_I3C_QUIRK_FIFO_EMPTY |
+ SVC_I3C_QUIRK_FALSE_SLVSTART |
+ SVC_I3C_QUIRK_DAA_CORRUPT,
+ .bsp_data = &amlogic_i3c_ao_data,
+};
+
+static const struct of_device_id amlogic_i3c_of_match_tbl[] = {
+ { .compatible = "amlogic,i3c-a9", .data = &amlogic_a9_drvdata },
+ { .compatible = "amlogic,i3c-ao-a9", .data = &amlogic_a9_ao_drvdata },
+ { /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, amlogic_i3c_of_match_tbl);
+
+static struct platform_driver amlogic_i3c_master = {
+ .probe = amlogic_i3c_probe,
+ .remove = amlogic_i3c_remove,
+ .driver = {
+ .name = "amlogic-i3c-master",
+ .of_match_table = amlogic_i3c_of_match_tbl,
+ .pm = &amlogic_i3c_pm_ops,
+ },
+};
+module_platform_driver(amlogic_i3c_master);
+
+MODULE_AUTHOR("Junyi Zhao <junyi.zhao@xxxxxxxxxxx>");
+MODULE_DESCRIPTION("Amlogic I3C master driver");
+MODULE_LICENSE("GPL");