Now that we have platform-specific hooks 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>
---
drivers/i3c/master/dw-i3c-master.c | 122 +++++++++++++++++++++++++++++
1 file changed, 122 insertions(+)
diff --git a/drivers/i3c/master/dw-i3c-master.c b/drivers/i3c/master/dw-i3c-master.c
index 49b891449222..9be3348cba0e 100644
--- a/drivers/i3c/master/dw-i3c-master.c
+++ b/drivers/i3c/master/dw-i3c-master.c
@@ -16,8 +16,10 @@
#include <linux/iopoll.h>
#include <linux/list.h>
#include <linux/module.h>
+#include <linux/mfd/syscon.h>
#include <linux/of.h>
#include <linux/platform_device.h>
+#include <linux/regmap.h>
#include <linux/reset.h>
#include <linux/slab.h>
@@ -201,6 +203,28 @@
#define XFER_TIMEOUT (msecs_to_jiffies(1000))
+/* 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 dw_i3c_master_caps {
u8 cmdfifodepth;
u8 datafifodepth;
@@ -224,6 +248,12 @@ struct dw_i3c_xfer {
struct dw_i3c_cmd cmds[];
};
+struct pdata_ast2600 {
+ struct regmap *global_regs;
+ unsigned int global_idx;
+ unsigned int sda_pullup;
+};
+
struct dw_i3c_master {
struct i3c_master_controller base;
u16 maxdevs;
@@ -245,6 +275,7 @@ struct dw_i3c_master {
/* platform-specific data */
const struct dw_i3c_platform_ops *platform_ops;
union {
+ struct pdata_ast2600 ast2600;
} pdata;
};
@@ -1145,6 +1176,97 @@ static const struct i3c_master_controller_ops dw_mipi_i3c_ops = {
.i2c_xfers = dw_i3c_master_i2c_xfers,
};
+/* hardware-specific ops */
+
+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_probe(struct dw_i3c_master *master,
+ struct platform_device *pdev)
+{
+ struct pdata_ast2600 *pdata = &master->pdata.ast2600;
+ struct device_node *np = pdev->dev.of_node;
+ struct of_phandle_args gspec;
+ int rc;
+
+ rc = of_parse_phandle_with_fixed_args(np, "aspeed,global-regs", 1, 0,
+ &gspec);
+ if (rc)
+ return -ENODEV;
+
+ pdata->global_regs = syscon_node_to_regmap(gspec.np);
+ of_node_put(gspec.np);
+
+ if (IS_ERR(pdata->global_regs))
+ return PTR_ERR(pdata->global_regs);
+
+ pdata->global_idx = gspec.args[0];
+
+ rc = of_property_read_u32(np, "sda-pullup-ohms", &pdata->sda_pullup);
+ if (rc)
+ pdata->sda_pullup = AST2600_DEFAULT_SDA_PULLUP_OHMS;
+
+ rc = ast2600_i3c_pullup_to_reg(pdata->sda_pullup, NULL);
+ if (rc)
+ dev_err(&master->base.dev, "invalid sda-pullup value %d\n",
+ pdata->sda_pullup);
+
+ return rc;
+}
+
+static int ast2600_i3c_init(struct dw_i3c_master *master)
+{
+ struct pdata_ast2600 *pdata = &master->pdata.ast2600;
+ u32 reg = 0;
+ int rc;
+
+ /* reg0: set SDA pullup values */
+ rc = ast2600_i3c_pullup_to_reg(pdata->sda_pullup, ®);
+ if (rc)
+ return rc;
+
+ rc = regmap_write(pdata->global_regs,
+ AST2600_I3CG_REG0(pdata->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(pdata->global_idx);
+ rc = regmap_write(pdata->global_regs,
+ AST2600_I3CG_REG1(pdata->global_idx), reg);
+
+ return rc;
+}
+
+static const struct dw_i3c_platform_ops ast2600_platform_ops = {
+ .probe = ast2600_i3c_probe,
+ .init = ast2600_i3c_init,
+};
+
static const struct of_device_id dw_i3c_master_of_match[] = {
{ .compatible = "snps,dw-i3c-master-1.00a", },
{},
--
2.39.1
