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1// SPDX-License-Identifier: GPL-2.02/*3 * Copyright (c) 2023 Code Construct4 *5 * Author: Jeremy Kerr <jk@codeconstruct.com.au>6 */7 8#include <linux/mfd/syscon.h>9#include <linux/module.h>10#include <linux/of.h>11#include <linux/platform_device.h>12#include <linux/regmap.h>13 14#include "dw-i3c-master.h"15 16/* AST2600-specific global register set */17#define AST2600_I3CG_REG0(idx) (((idx) * 4 * 4) + 0x10)18#define AST2600_I3CG_REG1(idx) (((idx) * 4 * 4) + 0x14)19 20#define AST2600_I3CG_REG0_SDA_PULLUP_EN_MASK GENMASK(29, 28)21#define AST2600_I3CG_REG0_SDA_PULLUP_EN_2K (0x0 << 28)22#define AST2600_I3CG_REG0_SDA_PULLUP_EN_750 (0x2 << 28)23#define AST2600_I3CG_REG0_SDA_PULLUP_EN_545 (0x3 << 28)24 25#define AST2600_I3CG_REG1_I2C_MODE BIT(0)26#define AST2600_I3CG_REG1_TEST_MODE BIT(1)27#define AST2600_I3CG_REG1_ACT_MODE_MASK GENMASK(3, 2)28#define AST2600_I3CG_REG1_ACT_MODE(x) (((x) << 2) & AST2600_I3CG_REG1_ACT_MODE_MASK)29#define AST2600_I3CG_REG1_PENDING_INT_MASK GENMASK(7, 4)30#define AST2600_I3CG_REG1_PENDING_INT(x) (((x) << 4) & AST2600_I3CG_REG1_PENDING_INT_MASK)31#define AST2600_I3CG_REG1_SA_MASK GENMASK(14, 8)32#define AST2600_I3CG_REG1_SA(x) (((x) << 8) & AST2600_I3CG_REG1_SA_MASK)33#define AST2600_I3CG_REG1_SA_EN BIT(15)34#define AST2600_I3CG_REG1_INST_ID_MASK GENMASK(19, 16)35#define AST2600_I3CG_REG1_INST_ID(x) (((x) << 16) & AST2600_I3CG_REG1_INST_ID_MASK)36 37#define AST2600_DEFAULT_SDA_PULLUP_OHMS 200038 39#define DEV_ADDR_TABLE_IBI_PEC BIT(11)40 41struct ast2600_i3c {42 struct dw_i3c_master dw;43 struct regmap *global_regs;44 unsigned int global_idx;45 unsigned int sda_pullup;46};47 48static struct ast2600_i3c *to_ast2600_i3c(struct dw_i3c_master *dw)49{50 return container_of(dw, struct ast2600_i3c, dw);51}52 53static int ast2600_i3c_pullup_to_reg(unsigned int ohms, u32 *regp)54{55 u32 reg;56 57 switch (ohms) {58 case 2000:59 reg = AST2600_I3CG_REG0_SDA_PULLUP_EN_2K;60 break;61 case 750:62 reg = AST2600_I3CG_REG0_SDA_PULLUP_EN_750;63 break;64 case 545:65 reg = AST2600_I3CG_REG0_SDA_PULLUP_EN_545;66 break;67 default:68 return -EINVAL;69 }70 71 if (regp)72 *regp = reg;73 74 return 0;75}76 77static int ast2600_i3c_init(struct dw_i3c_master *dw)78{79 struct ast2600_i3c *i3c = to_ast2600_i3c(dw);80 u32 reg = 0;81 int rc;82 83 /* reg0: set SDA pullup values */84 rc = ast2600_i3c_pullup_to_reg(i3c->sda_pullup, ®);85 if (rc)86 return rc;87 88 rc = regmap_write(i3c->global_regs,89 AST2600_I3CG_REG0(i3c->global_idx), reg);90 if (rc)91 return rc;92 93 /* reg1: set up the instance id, but leave everything else disabled,94 * as it's all for client mode95 */96 reg = AST2600_I3CG_REG1_INST_ID(i3c->global_idx);97 rc = regmap_write(i3c->global_regs,98 AST2600_I3CG_REG1(i3c->global_idx), reg);99 100 return rc;101}102 103static void ast2600_i3c_set_dat_ibi(struct dw_i3c_master *i3c,104 struct i3c_dev_desc *dev,105 bool enable, u32 *dat)106{107 /*108 * The ast2600 i3c controller will lock up on receiving 4n+1-byte IBIs109 * if the PEC is disabled. We have no way to restrict the length of110 * IBIs sent to the controller, so we need to unconditionally enable111 * PEC checking, which means we drop a byte of payload data112 */113 if (enable && dev->info.bcr & I3C_BCR_IBI_PAYLOAD) {114 dev_warn_once(&i3c->base.dev,115 "Enabling PEC workaround. IBI payloads will be truncated\n");116 *dat |= DEV_ADDR_TABLE_IBI_PEC;117 }118}119 120static const struct dw_i3c_platform_ops ast2600_i3c_ops = {121 .init = ast2600_i3c_init,122 .set_dat_ibi = ast2600_i3c_set_dat_ibi,123};124 125static int ast2600_i3c_probe(struct platform_device *pdev)126{127 struct device_node *np = pdev->dev.of_node;128 struct of_phandle_args gspec;129 struct ast2600_i3c *i3c;130 int rc;131 132 i3c = devm_kzalloc(&pdev->dev, sizeof(*i3c), GFP_KERNEL);133 if (!i3c)134 return -ENOMEM;135 136 rc = of_parse_phandle_with_fixed_args(np, "aspeed,global-regs", 1, 0,137 &gspec);138 if (rc)139 return -ENODEV;140 141 i3c->global_regs = syscon_node_to_regmap(gspec.np);142 of_node_put(gspec.np);143 144 if (IS_ERR(i3c->global_regs))145 return PTR_ERR(i3c->global_regs);146 147 i3c->global_idx = gspec.args[0];148 149 rc = of_property_read_u32(np, "sda-pullup-ohms", &i3c->sda_pullup);150 if (rc)151 i3c->sda_pullup = AST2600_DEFAULT_SDA_PULLUP_OHMS;152 153 rc = ast2600_i3c_pullup_to_reg(i3c->sda_pullup, NULL);154 if (rc)155 dev_err(&pdev->dev, "invalid sda-pullup value %d\n",156 i3c->sda_pullup);157 158 i3c->dw.platform_ops = &ast2600_i3c_ops;159 return dw_i3c_common_probe(&i3c->dw, pdev);160}161 162static void ast2600_i3c_remove(struct platform_device *pdev)163{164 struct dw_i3c_master *dw_i3c = platform_get_drvdata(pdev);165 166 dw_i3c_common_remove(dw_i3c);167}168 169static const struct of_device_id ast2600_i3c_master_of_match[] = {170 { .compatible = "aspeed,ast2600-i3c", },171 {},172};173MODULE_DEVICE_TABLE(of, ast2600_i3c_master_of_match);174 175static struct platform_driver ast2600_i3c_driver = {176 .probe = ast2600_i3c_probe,177 .remove_new = ast2600_i3c_remove,178 .driver = {179 .name = "ast2600-i3c-master",180 .of_match_table = ast2600_i3c_master_of_match,181 },182};183module_platform_driver(ast2600_i3c_driver);184 185MODULE_AUTHOR("Jeremy Kerr <jk@codeconstruct.com.au>");186MODULE_DESCRIPTION("ASPEED AST2600 I3C driver");187MODULE_LICENSE("GPL");188