Now that we have platform-specific infrastructure for the dw i3c driver,
add platform support for the ASPEED AST2600 SoC.
The AST2600 has a small set of "i3c global" registers, providing
platform-level i3c configuration outside of the i3c core.
For the ast2600, we need a couple of extra setup operations:
- on probe: find the i3c global register set and parse the SDA pullup
resistor values
- on init: set the pullups accordingly, and set the i3c instance IDs
Signed-off-by: Jeremy Kerr <jk@xxxxxxxxxxxxxxxxxxxx>
---
v2:
- use new dw platform infrastructure
v3:
- switch to embedded struct for platform data
- drop of_match_ptr()
---
MAINTAINERS | 6 +
drivers/i3c/master/Kconfig | 14 ++
drivers/i3c/master/Makefile | 1 +
drivers/i3c/master/ast2600-i3c-master.c | 168 ++++++++++++++++++++++++
4 files changed, 189 insertions(+)
create mode 100644 drivers/i3c/master/ast2600-i3c-master.c
diff --git a/MAINTAINERS b/MAINTAINERS
index bd8ebc25afcf..ecadd5ccf771 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -9714,6 +9714,12 @@ S: Orphan
F: Documentation/devicetree/bindings/i3c/snps,dw-i3c-master.yaml
F: drivers/i3c/master/dw*
+I3C DRIVER FOR ASPEED AST2600
+M: Jeremy Kerr <jk@xxxxxxxxxxxxxxxxxxxx>
+S: Maintained
+F: Documentation/devicetree/bindings/i3c/aspeed,ast2600-i3c.yaml
+F: drivers/i3c/master/ast2600-i3c-master.c
+
I3C SUBSYSTEM
M: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx>
L: linux-i3c@xxxxxxxxxxxxxxxxxxx (moderated for non-subscribers)
diff --git a/drivers/i3c/master/Kconfig b/drivers/i3c/master/Kconfig
index 3b8f95916f46..90dee3ec5520 100644
--- a/drivers/i3c/master/Kconfig
+++ b/drivers/i3c/master/Kconfig
@@ -22,6 +22,20 @@ config DW_I3C_MASTER
This driver can also be built as a module. If so, the module
will be called dw-i3c-master.
+config AST2600_I3C_MASTER
+ tristate "ASPEED AST2600 I3C master driver"
+ depends on DW_I3C_MASTER
+ depends on ARCH_ASPEED || COMPILE_TEST
+ select MFD_SYSCON
+ help
+ Support for ASPEED AST2600 I3C Controller.
+
+ This hardware is an instance of the DW I3C controller; this
+ driver adds platform- specific support for AST2600 hardware.
+
+ This driver can also be built as a module. If so, the module
+ will be called ast2600-i3c-master.
+
config SVC_I3C_MASTER
tristate "Silvaco I3C Dual-Role Master driver"
depends on I3C
diff --git a/drivers/i3c/master/Makefile b/drivers/i3c/master/Makefile
index b3fee0f690b2..3e97960160bc 100644
--- a/drivers/i3c/master/Makefile
+++ b/drivers/i3c/master/Makefile
@@ -1,5 +1,6 @@
# SPDX-License-Identifier: GPL-2.0-only
obj-$(CONFIG_CDNS_I3C_MASTER) += i3c-master-cdns.o
obj-$(CONFIG_DW_I3C_MASTER) += dw-i3c-master.o
+obj-$(CONFIG_AST2600_I3C_MASTER) += ast2600-i3c-master.o
obj-$(CONFIG_SVC_I3C_MASTER) += svc-i3c-master.o
obj-$(CONFIG_MIPI_I3C_HCI) += mipi-i3c-hci/
diff --git a/drivers/i3c/master/ast2600-i3c-master.c b/drivers/i3c/master/ast2600-i3c-master.c
new file mode 100644
index 000000000000..d265669c04f1
--- /dev/null
+++ b/drivers/i3c/master/ast2600-i3c-master.c
@@ -0,0 +1,168 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2023 Code Construct
+ *
+ * Author: Jeremy Kerr <jk@xxxxxxxxxxxxxxxxxxxx>
+ */
+
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#include "dw-i3c-master.h"
+
+/* AST2600-specific global register set */
+#define AST2600_I3CG_REG0(idx) (((idx) * 4 * 4) + 0x10)
+#define AST2600_I3CG_REG1(idx) (((idx) * 4 * 4) + 0x14)
+
+#define AST2600_I3CG_REG0_SDA_PULLUP_EN_MASK GENMASK(29, 28)
+#define AST2600_I3CG_REG0_SDA_PULLUP_EN_2K (0x0 << 28)
+#define AST2600_I3CG_REG0_SDA_PULLUP_EN_750 (0x2 << 28)
+
+#define AST2600_I3CG_REG1_I2C_MODE BIT(0)
+#define AST2600_I3CG_REG1_TEST_MODE BIT(1)
+#define AST2600_I3CG_REG1_ACT_MODE_MASK GENMASK(3, 2)
+#define AST2600_I3CG_REG1_ACT_MODE(x) (((x) << 2) & AST2600_I3CG_REG1_ACT_MODE_MASK)
+#define AST2600_I3CG_REG1_PENDING_INT_MASK GENMASK(7, 4)
+#define AST2600_I3CG_REG1_PENDING_INT(x) (((x) << 4) & AST2600_I3CG_REG1_PENDING_INT_MASK)
+#define AST2600_I3CG_REG1_SA_MASK GENMASK(14, 8)
+#define AST2600_I3CG_REG1_SA(x) (((x) << 8) & AST2600_I3CG_REG1_SA_MASK)
+#define AST2600_I3CG_REG1_SA_EN BIT(15)
+#define AST2600_I3CG_REG1_INST_ID_MASK GENMASK(19, 16)
+#define AST2600_I3CG_REG1_INST_ID(x) (((x) << 16) & AST2600_I3CG_REG1_INST_ID_MASK)
+
+#define AST2600_DEFAULT_SDA_PULLUP_OHMS 2000
+
+struct ast2600_i3c {
+ struct dw_i3c_master dw;
+ struct regmap *global_regs;
+ unsigned int global_idx;
+ unsigned int sda_pullup;
+};
+
+static struct ast2600_i3c *to_ast2600_i3c(struct dw_i3c_master *dw)
+{
+ return container_of(dw, struct ast2600_i3c, dw);
+}
+
+static int ast2600_i3c_pullup_to_reg(unsigned int ohms, u32 *regp)
+{
+ u32 reg;
+
+ switch (ohms) {
+ case 2000:
+ reg = AST2600_I3CG_REG0_SDA_PULLUP_EN_2K;
+ break;
+ case 750:
+ reg = AST2600_I3CG_REG0_SDA_PULLUP_EN_750;
+ break;
+ case 545:
+ reg = AST2600_I3CG_REG0_SDA_PULLUP_EN_2K |
+ AST2600_I3CG_REG0_SDA_PULLUP_EN_750;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ if (regp)
+ *regp = reg;
+
+ return 0;
+}
+
+static int ast2600_i3c_init(struct dw_i3c_master *dw)
+{
+ struct ast2600_i3c *i3c = to_ast2600_i3c(dw);
+ u32 reg = 0;
+ int rc;
+
+ /* reg0: set SDA pullup values */
+ rc = ast2600_i3c_pullup_to_reg(i3c->sda_pullup, ®);
+ if (rc)
+ return rc;
+
+ rc = regmap_write(i3c->global_regs,
+ AST2600_I3CG_REG0(i3c->global_idx), reg);
+ if (rc)
+ return rc;
+
+ /* reg1: set up the instance id, but leave everything else disabled,
+ * as it's all for client mode
+ */
+ reg = AST2600_I3CG_REG1_INST_ID(i3c->global_idx);
+ rc = regmap_write(i3c->global_regs,
+ AST2600_I3CG_REG1(i3c->global_idx), reg);
+
+ return rc;
+}
+
+const struct dw_i3c_platform_ops ast2600_i3c_ops = {
+ .init = ast2600_i3c_init,
+};
+
+static int ast2600_i3c_probe(struct platform_device *pdev)
+{
+ struct device_node *np = pdev->dev.of_node;
+ struct of_phandle_args gspec;
+ struct ast2600_i3c *i3c;
+ int rc;
+
+ i3c = devm_kzalloc(&pdev->dev, sizeof(*i3c), GFP_KERNEL);
+ if (!i3c)
+ return -ENOMEM;
+
+ rc = of_parse_phandle_with_fixed_args(np, "aspeed,global-regs", 1, 0,
+ &gspec);
+ if (rc)
+ return -ENODEV;
+
+ i3c->global_regs = syscon_node_to_regmap(gspec.np);
+ of_node_put(gspec.np);
+
+ if (IS_ERR(i3c->global_regs))
+ return PTR_ERR(i3c->global_regs);
+
+ i3c->global_idx = gspec.args[0];
+
+ rc = of_property_read_u32(np, "sda-pullup-ohms", &i3c->sda_pullup);
+ if (rc)
+ i3c->sda_pullup = AST2600_DEFAULT_SDA_PULLUP_OHMS;
+
+ rc = ast2600_i3c_pullup_to_reg(i3c->sda_pullup, NULL);
+ if (rc)
+ dev_err(&pdev->dev, "invalid sda-pullup value %d\n",
+ i3c->sda_pullup);
+
+ i3c->dw.platform_ops = &ast2600_i3c_ops;
+ return dw_i3c_common_probe(&i3c->dw, pdev);
+}
+
+static int ast2600_i3c_remove(struct platform_device *pdev)
+{
+ struct dw_i3c_master *dw_i3c = platform_get_drvdata(pdev);
+
+ return dw_i3c_common_remove(dw_i3c);
+}
+
+static const struct of_device_id ast2600_i3c_master_of_match[] = {
+ { .compatible = "aspeed,ast2600-i3c", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, ast2600_i3c_master_of_match);
+
+static struct platform_driver ast2600_i3c_driver = {
+ .probe = ast2600_i3c_probe,
+ .remove = ast2600_i3c_remove,
+ .driver = {
+ .name = "ast2600-i3c-master",
+ .of_match_table = ast2600_i3c_master_of_match,
+ },
+};
+module_platform_driver(ast2600_i3c_driver);
+
+MODULE_AUTHOR("Jeremy Kerr <jk@xxxxxxxxxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("ASPEED AST2600 I3C driver");
+MODULE_LICENSE("GPL");
--
2.39.1
