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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2023 Code Construct
*
* Author: Jeremy Kerr <jk@codeconstruct.com.au>
*/
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/of.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_REG0_SDA_PULLUP_EN_545 (0x3 << 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
#define DEV_ADDR_TABLE_IBI_PEC BIT(11)
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_545;
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;
}
static void ast2600_i3c_set_dat_ibi(struct dw_i3c_master *i3c,
struct i3c_dev_desc *dev,
bool enable, u32 *dat)
{
/*
* The ast2600 i3c controller will lock up on receiving 4n+1-byte IBIs
* if the PEC is disabled. We have no way to restrict the length of
* IBIs sent to the controller, so we need to unconditionally enable
* PEC checking, which means we drop a byte of payload data
*/
if (enable && dev->info.bcr & I3C_BCR_IBI_PAYLOAD) {
dev_warn_once(&i3c->base.dev,
"Enabling PEC workaround. IBI payloads will be truncated\n");
*dat |= DEV_ADDR_TABLE_IBI_PEC;
}
}
static const struct dw_i3c_platform_ops ast2600_i3c_ops = {
.init = ast2600_i3c_init,
.set_dat_ibi = ast2600_i3c_set_dat_ibi,
};
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 void ast2600_i3c_remove(struct platform_device *pdev)
{
struct dw_i3c_master *dw_i3c = platform_get_drvdata(pdev);
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@codeconstruct.com.au>");
MODULE_DESCRIPTION("ASPEED AST2600 I3C driver");
MODULE_LICENSE("GPL");
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