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![Ashish Jangam](/assets/img/avatar_default.png)
An issue has been reported where the PMIC either locks up or fails to respond following a system Reset. This could result in a second write in which the bus writes the current content of the write buffer to address of the last I2C access. The failure case is where this unwanted write transfers incorrect data to a critical register. This patch fixes this issue to by following any read or write with a dummy read to a safe register address. A safe register address is one where the contents will not affect the operation of the system. Signed-off-by: Ashish Jangam <ashish.jangam@kpitcummins.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
228 lines
5 KiB
C
228 lines
5 KiB
C
/*
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* I2C access for DA9052 PMICs.
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*
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* Copyright(c) 2011 Dialog Semiconductor Ltd.
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*
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* Author: David Dajun Chen <dchen@diasemi.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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*/
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#include <linux/device.h>
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#include <linux/module.h>
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#include <linux/input.h>
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#include <linux/mfd/core.h>
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#include <linux/i2c.h>
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#include <linux/err.h>
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#include <linux/mfd/da9052/da9052.h>
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#include <linux/mfd/da9052/reg.h>
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#ifdef CONFIG_OF
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#include <linux/of.h>
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#include <linux/of_device.h>
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#endif
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/* I2C safe register check */
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static inline bool i2c_safe_reg(unsigned char reg)
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{
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switch (reg) {
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case DA9052_STATUS_A_REG:
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case DA9052_STATUS_B_REG:
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case DA9052_STATUS_C_REG:
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case DA9052_STATUS_D_REG:
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case DA9052_ADC_RES_L_REG:
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case DA9052_ADC_RES_H_REG:
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case DA9052_VDD_RES_REG:
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case DA9052_ICHG_AV_REG:
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case DA9052_TBAT_RES_REG:
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case DA9052_ADCIN4_RES_REG:
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case DA9052_ADCIN5_RES_REG:
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case DA9052_ADCIN6_RES_REG:
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case DA9052_TJUNC_RES_REG:
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case DA9052_TSI_X_MSB_REG:
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case DA9052_TSI_Y_MSB_REG:
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case DA9052_TSI_LSB_REG:
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case DA9052_TSI_Z_MSB_REG:
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return true;
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default:
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return false;
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}
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}
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/*
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* There is an issue with DA9052 and DA9053_AA/BA/BB PMIC where the PMIC
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* gets lockup up or fails to respond following a system reset.
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* This fix is to follow any read or write with a dummy read to a safe
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* register.
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*/
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int da9052_i2c_fix(struct da9052 *da9052, unsigned char reg)
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{
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int val;
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switch (da9052->chip_id) {
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case DA9052:
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case DA9053_AA:
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case DA9053_BA:
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case DA9053_BB:
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/* A dummy read to a safe register address. */
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if (!i2c_safe_reg(reg))
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return regmap_read(da9052->regmap,
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DA9052_PARK_REGISTER,
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&val);
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break;
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default:
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/*
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* For other chips parking of I2C register
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* to a safe place is not required.
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*/
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break;
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}
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return 0;
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}
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EXPORT_SYMBOL(da9052_i2c_fix);
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static int da9052_i2c_enable_multiwrite(struct da9052 *da9052)
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{
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int reg_val, ret;
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ret = regmap_read(da9052->regmap, DA9052_CONTROL_B_REG, ®_val);
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if (ret < 0)
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return ret;
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if (reg_val & DA9052_CONTROL_B_WRITEMODE) {
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reg_val &= ~DA9052_CONTROL_B_WRITEMODE;
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ret = regmap_write(da9052->regmap, DA9052_CONTROL_B_REG,
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reg_val);
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if (ret < 0)
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return ret;
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}
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return 0;
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}
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static const struct i2c_device_id da9052_i2c_id[] = {
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{"da9052", DA9052},
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{"da9053-aa", DA9053_AA},
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{"da9053-ba", DA9053_BA},
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{"da9053-bb", DA9053_BB},
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{}
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};
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#ifdef CONFIG_OF
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static const struct of_device_id dialog_dt_ids[] = {
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{ .compatible = "dlg,da9052", .data = &da9052_i2c_id[0] },
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{ .compatible = "dlg,da9053-aa", .data = &da9052_i2c_id[1] },
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{ .compatible = "dlg,da9053-ab", .data = &da9052_i2c_id[2] },
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{ .compatible = "dlg,da9053-bb", .data = &da9052_i2c_id[3] },
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{ /* sentinel */ }
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};
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#endif
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static int da9052_i2c_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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{
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struct da9052 *da9052;
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int ret;
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da9052 = devm_kzalloc(&client->dev, sizeof(struct da9052), GFP_KERNEL);
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if (!da9052)
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return -ENOMEM;
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if (!i2c_check_functionality(client->adapter,
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I2C_FUNC_SMBUS_BYTE_DATA)) {
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dev_info(&client->dev, "Error in %s:i2c_check_functionality\n",
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__func__);
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return -ENODEV;
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}
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da9052->dev = &client->dev;
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da9052->chip_irq = client->irq;
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da9052->fix_io = da9052_i2c_fix;
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i2c_set_clientdata(client, da9052);
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da9052->regmap = devm_regmap_init_i2c(client, &da9052_regmap_config);
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if (IS_ERR(da9052->regmap)) {
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ret = PTR_ERR(da9052->regmap);
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dev_err(&client->dev, "Failed to allocate register map: %d\n",
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ret);
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return ret;
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}
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ret = da9052_i2c_enable_multiwrite(da9052);
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if (ret < 0)
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return ret;
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#ifdef CONFIG_OF
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if (!id) {
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struct device_node *np = client->dev.of_node;
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const struct of_device_id *deviceid;
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deviceid = of_match_node(dialog_dt_ids, np);
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id = deviceid->data;
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}
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#endif
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if (!id) {
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ret = -ENODEV;
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dev_err(&client->dev, "id is null.\n");
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return ret;
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}
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ret = da9052_device_init(da9052, id->driver_data);
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if (ret != 0)
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return ret;
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return 0;
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}
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static int da9052_i2c_remove(struct i2c_client *client)
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{
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struct da9052 *da9052 = i2c_get_clientdata(client);
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da9052_device_exit(da9052);
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return 0;
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}
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static struct i2c_driver da9052_i2c_driver = {
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.probe = da9052_i2c_probe,
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.remove = da9052_i2c_remove,
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.id_table = da9052_i2c_id,
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.driver = {
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.name = "da9052",
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.owner = THIS_MODULE,
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#ifdef CONFIG_OF
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.of_match_table = dialog_dt_ids,
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#endif
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},
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};
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static int __init da9052_i2c_init(void)
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{
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int ret;
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ret = i2c_add_driver(&da9052_i2c_driver);
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if (ret != 0) {
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pr_err("DA9052 I2C registration failed %d\n", ret);
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return ret;
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}
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return 0;
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}
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subsys_initcall(da9052_i2c_init);
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static void __exit da9052_i2c_exit(void)
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{
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i2c_del_driver(&da9052_i2c_driver);
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}
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module_exit(da9052_i2c_exit);
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MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>");
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MODULE_DESCRIPTION("I2C driver for Dialog DA9052 PMIC");
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MODULE_LICENSE("GPL");
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