1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Ampere Altra Family SMPro core driver
  4 * Copyright (c) 2022, Ampere Computing LLC
  5 */
  6
  7#include <linux/i2c.h>
  8#include <linux/kernel.h>
  9#include <linux/mfd/core.h>
 10#include <linux/module.h>
 11#include <linux/of_platform.h>
 12#include <linux/regmap.h>
 13
 14/* Identification Registers */
 15#define MANUFACTURER_ID_REG     0x02
 16#define AMPERE_MANUFACTURER_ID  0xCD3A
 17
 18#define CORE_CE_ERR_DATA        0x82
 19#define CORE_UE_ERR_DATA        0x85
 20#define MEM_CE_ERR_DATA         0x92
 21#define MEM_UE_ERR_DATA         0x95
 22#define PCIE_CE_ERR_DATA        0xC2
 23#define PCIE_UE_ERR_DATA        0xC5
 24#define OTHER_CE_ERR_DATA       0xD2
 25#define OTHER_UE_ERR_DATA       0xDA
 26
 27static int smpro_core_write(void *context, const void *data, size_t count)
 28{
 29	struct device *dev = context;
 30	struct i2c_client *i2c = to_i2c_client(dev);
 31	int ret;
 32
 33	ret = i2c_master_send(i2c, data, count);
 34	if (unlikely(ret != count))
 35		return (ret < 0) ? ret : -EIO;
 36
 37	return 0;
 38}
 39
 40static int smpro_core_read(void *context, const void *reg, size_t reg_size,
 41			   void *val, size_t val_size)
 42{
 43	struct device *dev = context;
 44	struct i2c_client *i2c = to_i2c_client(dev);
 45	struct i2c_msg xfer[2];
 46	unsigned char buf[2];
 47	int ret;
 48
 49	xfer[0].addr = i2c->addr;
 50	xfer[0].flags = 0;
 51
 52	buf[0] = *(u8 *)reg;
 53	buf[1] = val_size;
 54	xfer[0].len = 2;
 55	xfer[0].buf = buf;
 56
 57	xfer[1].addr = i2c->addr;
 58	xfer[1].flags = I2C_M_RD;
 59	xfer[1].len = val_size;
 60	xfer[1].buf = val;
 61
 62	ret = i2c_transfer(i2c->adapter, xfer, 2);
 63	if (unlikely(ret != 2))
 64		return (ret < 0) ? ret : -EIO;
 65
 66	return 0;
 67}
 68
 69static const struct regmap_bus smpro_regmap_bus = {
 70	.read = smpro_core_read,
 71	.write = smpro_core_write,
 72	.val_format_endian_default = REGMAP_ENDIAN_BIG,
 73};
 74
 75static bool smpro_core_readable_noinc_reg(struct device *dev, unsigned int reg)
 76{
 77	return  (reg == CORE_CE_ERR_DATA || reg == CORE_UE_ERR_DATA ||
 78		 reg == MEM_CE_ERR_DATA || reg == MEM_UE_ERR_DATA ||
 79		 reg == PCIE_CE_ERR_DATA || reg == PCIE_UE_ERR_DATA ||
 80		 reg == OTHER_CE_ERR_DATA || reg == OTHER_UE_ERR_DATA);
 81}
 82
 83static const struct regmap_config smpro_regmap_config = {
 84	.reg_bits = 8,
 85	.val_bits = 16,
 86	.readable_noinc_reg = smpro_core_readable_noinc_reg,
 87};
 88
 89static const struct mfd_cell smpro_devs[] = {
 90	MFD_CELL_NAME("smpro-hwmon"),
 91	MFD_CELL_NAME("smpro-errmon"),
 92	MFD_CELL_NAME("smpro-misc"),
 93};
 94
 95static int smpro_core_probe(struct i2c_client *i2c)
 96{
 97	const struct regmap_config *config;
 98	struct regmap *regmap;
 99	unsigned int val;
100	int ret;
101
102	config = device_get_match_data(&i2c->dev);
103	if (!config)
104		return -EINVAL;
105
106	regmap = devm_regmap_init(&i2c->dev, &smpro_regmap_bus, &i2c->dev, config);
107	if (IS_ERR(regmap))
108		return PTR_ERR(regmap);
109
110	ret = regmap_read(regmap, MANUFACTURER_ID_REG, &val);
111	if (ret)
112		return ret;
113
114	if (val != AMPERE_MANUFACTURER_ID)
115		return -ENODEV;
116
117	return devm_mfd_add_devices(&i2c->dev, PLATFORM_DEVID_AUTO,
118				    smpro_devs, ARRAY_SIZE(smpro_devs), NULL, 0, NULL);
119}
120
121static const struct of_device_id smpro_core_of_match[] = {
122	{ .compatible = "ampere,smpro", .data = &smpro_regmap_config },
123	{}
124};
125MODULE_DEVICE_TABLE(of, smpro_core_of_match);
126
127static struct i2c_driver smpro_core_driver = {
128	.probe = smpro_core_probe,
129	.driver = {
130		.name = "smpro-core",
131		.of_match_table = smpro_core_of_match,
132	},
133};
134module_i2c_driver(smpro_core_driver);
135
136MODULE_AUTHOR("Quan Nguyen <quan@os.amperecomputing.com>");
137MODULE_DESCRIPTION("SMPRO CORE - I2C driver");
138MODULE_LICENSE("GPL");