diff options
| -rw-r--r-- | Documentation/devicetree/bindings/i2c/i2c-opal.txt | 37 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/opal.h | 29 | ||||
| -rw-r--r-- | arch/powerpc/platforms/powernv/opal-wrappers.S | 1 | ||||
| -rw-r--r-- | arch/powerpc/platforms/powernv/opal.c | 12 | ||||
| -rw-r--r-- | drivers/i2c/busses/Kconfig | 11 | ||||
| -rw-r--r-- | drivers/i2c/busses/Makefile | 1 | ||||
| -rw-r--r-- | drivers/i2c/busses/i2c-opal.c | 294 |
7 files changed, 385 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/i2c/i2c-opal.txt b/Documentation/devicetree/bindings/i2c/i2c-opal.txt new file mode 100644 index 000000000000..12bc61465ee5 --- /dev/null +++ b/Documentation/devicetree/bindings/i2c/i2c-opal.txt @@ -0,0 +1,37 @@ +Device-tree bindings for I2C OPAL driver +---------------------------------------- + +Most of the device node and properties layout is specific to the firmware and +used by the firmware itself for configuring the port. From the linux +perspective, the properties of use are "ibm,port-name" and "ibm,opal-id". + +Required properties: + +- reg: Port-id within a given master +- compatible: must be "ibm,opal-i2c" +- ibm,opal-id: Refers to a specific bus and used to identify it when calling + the relevant OPAL functions. +- bus-frequency: Operating frequency of the i2c bus (in HZ). Informational for + linux, used by the FW though. + +Optional properties: +- ibm,port-name: Firmware provides this name that uniquely identifies the i2c + port. + +The node contains a number of other properties that are used by the FW itself +and depend on the specific hardware implementation. The example below depicts +a P8 on-chip bus. + +Example: + +i2c-bus@0 { + reg = <0x0>; + bus-frequency = <0x61a80>; + compatible = "ibm,power8-i2c-port", "ibm,opal-i2c"; + ibm,opal-id = <0x1>; + ibm,port-name = "p8_00000000_e1p0"; + #address-cells = <0x1>; + phandle = <0x10000006>; + #size-cells = <0x0>; + linux,phandle = <0x10000006>; +}; diff --git a/arch/powerpc/include/asm/opal.h b/arch/powerpc/include/asm/opal.h index 5cd8d2fddba9..4095749c973f 100644 --- a/arch/powerpc/include/asm/opal.h +++ b/arch/powerpc/include/asm/opal.h @@ -56,6 +56,14 @@ struct opal_sg_list { #define OPAL_HARDWARE_FROZEN -13 #define OPAL_WRONG_STATE -14 #define OPAL_ASYNC_COMPLETION -15 +#define OPAL_I2C_TIMEOUT -17 +#define OPAL_I2C_INVALID_CMD -18 +#define OPAL_I2C_LBUS_PARITY -19 +#define OPAL_I2C_BKEND_OVERRUN -20 +#define OPAL_I2C_BKEND_ACCESS -21 +#define OPAL_I2C_ARBT_LOST -22 +#define OPAL_I2C_NACK_RCVD -23 +#define OPAL_I2C_STOP_ERR -24 /* API Tokens (in r0) */ #define OPAL_INVALID_CALL -1 @@ -158,6 +166,7 @@ struct opal_sg_list { #define OPAL_READ_TPO 104 #define OPAL_IPMI_SEND 107 #define OPAL_IPMI_RECV 108 +#define OPAL_I2C_REQUEST 109 #ifndef __ASSEMBLY__ @@ -712,6 +721,24 @@ typedef struct oppanel_line { uint64_t line_len; } oppanel_line_t; +/* OPAL I2C request */ +struct opal_i2c_request { + uint8_t type; +#define OPAL_I2C_RAW_READ 0 +#define OPAL_I2C_RAW_WRITE 1 +#define OPAL_I2C_SM_READ 2 +#define OPAL_I2C_SM_WRITE 3 + uint8_t flags; +#define OPAL_I2C_ADDR_10 0x01 /* Not supported yet */ + uint8_t subaddr_sz; /* Max 4 */ + uint8_t reserved; + __be16 addr; /* 7 or 10 bit address */ + __be16 reserved2; + __be32 subaddr; /* Sub-address if any */ + __be32 size; /* Data size */ + __be64 buffer_ra; /* Buffer real address */ +}; + /* /sys/firmware/opal */ extern struct kobject *opal_kobj; @@ -881,6 +908,8 @@ int64_t opal_ipmi_send(uint64_t interface, struct opal_ipmi_msg *msg, uint64_t msg_len); int64_t opal_ipmi_recv(uint64_t interface, struct opal_ipmi_msg *msg, uint64_t *msg_len); +int64_t opal_i2c_request(uint64_t async_token, uint32_t bus_id, + struct opal_i2c_request *oreq); /* Internal functions */ extern int early_init_dt_scan_opal(unsigned long node, const char *uname, diff --git a/arch/powerpc/platforms/powernv/opal-wrappers.S b/arch/powerpc/platforms/powernv/opal-wrappers.S index 0a299be588af..2111e08d406b 100644 --- a/arch/powerpc/platforms/powernv/opal-wrappers.S +++ b/arch/powerpc/platforms/powernv/opal-wrappers.S @@ -254,3 +254,4 @@ OPAL_CALL(opal_tpo_write, OPAL_WRITE_TPO); OPAL_CALL(opal_tpo_read, OPAL_READ_TPO); OPAL_CALL(opal_ipmi_send, OPAL_IPMI_SEND); OPAL_CALL(opal_ipmi_recv, OPAL_IPMI_RECV); +OPAL_CALL(opal_i2c_request, OPAL_I2C_REQUEST); diff --git a/arch/powerpc/platforms/powernv/opal.c b/arch/powerpc/platforms/powernv/opal.c index cb0b6de79cd4..aa316d820736 100644 --- a/arch/powerpc/platforms/powernv/opal.c +++ b/arch/powerpc/platforms/powernv/opal.c @@ -653,6 +653,14 @@ static void opal_ipmi_init(struct device_node *opal_node) of_platform_device_create(np, NULL, NULL); } +static void opal_i2c_create_devs(void) +{ + struct device_node *np; + + for_each_compatible_node(np, NULL, "ibm,opal-i2c") + of_platform_device_create(np, NULL, NULL); +} + static int __init opal_init(void) { struct device_node *np, *consoles; @@ -679,6 +687,9 @@ static int __init opal_init(void) of_node_put(consoles); } + /* Create i2c platform devices */ + opal_i2c_create_devs(); + /* Find all OPAL interrupts and request them */ irqs = of_get_property(opal_node, "opal-interrupts", &irqlen); pr_debug("opal: Found %d interrupts reserved for OPAL\n", @@ -824,3 +835,4 @@ EXPORT_SYMBOL_GPL(opal_rtc_read); EXPORT_SYMBOL_GPL(opal_rtc_write); EXPORT_SYMBOL_GPL(opal_tpo_read); EXPORT_SYMBOL_GPL(opal_tpo_write); +EXPORT_SYMBOL_GPL(opal_i2c_request); diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index 917c3585f45b..71ad6e11efb7 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -1044,4 +1044,15 @@ config SCx200_ACB This support is also available as a module. If so, the module will be called scx200_acb. +config I2C_OPAL + tristate "IBM OPAL I2C driver" + depends on PPC_POWERNV + default y + help + This exposes the PowerNV platform i2c busses to the linux i2c layer, + the driver is based on the OPAL interfaces. + + This driver can also be built as a module. If so, the module will be + called as i2c-opal. + endmenu diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile index 78d56c54ba2b..e23ec815e21f 100644 --- a/drivers/i2c/busses/Makefile +++ b/drivers/i2c/busses/Makefile @@ -99,6 +99,7 @@ obj-$(CONFIG_I2C_ACORN) += i2c-acorn.o obj-$(CONFIG_I2C_BCM_KONA) += i2c-bcm-kona.o obj-$(CONFIG_I2C_CROS_EC_TUNNEL) += i2c-cros-ec-tunnel.o obj-$(CONFIG_I2C_ELEKTOR) += i2c-elektor.o +obj-$(CONFIG_I2C_OPAL) += i2c-opal.o obj-$(CONFIG_I2C_PCA_ISA) += i2c-pca-isa.o obj-$(CONFIG_I2C_SIBYTE) += i2c-sibyte.o obj-$(CONFIG_SCx200_ACB) += scx200_acb.o diff --git a/drivers/i2c/busses/i2c-opal.c b/drivers/i2c/busses/i2c-opal.c new file mode 100644 index 000000000000..16f90b1a7508 --- /dev/null +++ b/drivers/i2c/busses/i2c-opal.c @@ -0,0 +1,294 @@ +/* + * IBM OPAL I2C driver + * Copyright (C) 2014 IBM + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. + */ + +#include <linux/device.h> +#include <linux/i2c.h> +#include <linux/kernel.h> +#include <linux/mm.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/slab.h> + +#include <asm/firmware.h> +#include <asm/opal.h> + +static int i2c_opal_translate_error(int rc) +{ + switch (rc) { + case OPAL_NO_MEM: + return -ENOMEM; + case OPAL_PARAMETER: + return -EINVAL; + case OPAL_I2C_ARBT_LOST: + return -EAGAIN; + case OPAL_I2C_TIMEOUT: + return -ETIMEDOUT; + case OPAL_I2C_NACK_RCVD: + return -ENXIO; + case OPAL_I2C_STOP_ERR: + return -EBUSY; + default: + return -EIO; + } +} + +static int i2c_opal_send_request(u32 bus_id, struct opal_i2c_request *req) +{ + struct opal_msg msg; + int token, rc; + + token = opal_async_get_token_interruptible(); + if (token < 0) { + if (token != -ERESTARTSYS) + pr_err("Failed to get the async token\n"); + + return token; + } + + rc = opal_i2c_request(token, bus_id, req); + if (rc != OPAL_ASYNC_COMPLETION) { + rc = i2c_opal_translate_error(rc); + goto exit; + } + + rc = opal_async_wait_response(token, &msg); + if (rc) + goto exit; + + rc = be64_to_cpu(msg.params[1]); + if (rc != OPAL_SUCCESS) { + rc = i2c_opal_translate_error(rc); + goto exit; + } + +exit: + opal_async_release_token(token); + return rc; +} + +static int i2c_opal_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, + int num) +{ + unsigned long opal_id = (unsigned long)adap->algo_data; + struct opal_i2c_request req; + int rc, i; + + /* We only support fairly simple combinations here of one + * or two messages + */ + memset(&req, 0, sizeof(req)); + switch(num) { + case 0: + return 0; + case 1: + req.type = (msgs[0].flags & I2C_M_RD) ? + OPAL_I2C_RAW_READ : OPAL_I2C_RAW_WRITE; + req.addr = cpu_to_be16(msgs[0].addr); + req.size = cpu_to_be32(msgs[0].len); + req.buffer_ra = cpu_to_be64(__pa(msgs[0].buf)); + break; + case 2: + /* For two messages, we basically support only simple + * smbus transactions of a write plus a read. We might + * want to allow also two writes but we'd have to bounce + * the data into a single buffer. + */ + if ((msgs[0].flags & I2C_M_RD) || !(msgs[1].flags & I2C_M_RD)) + return -EOPNOTSUPP; + if (msgs[0].len > 4) + return -EOPNOTSUPP; + if (msgs[0].addr != msgs[1].addr) + return -EOPNOTSUPP; + req.type = OPAL_I2C_SM_READ; + req.addr = cpu_to_be16(msgs[0].addr); + req.subaddr_sz = msgs[0].len; + for (i = 0; i < msgs[0].len; i++) + req.subaddr = (req.subaddr << 8) | msgs[0].buf[i]; + req.subaddr = cpu_to_be32(req.subaddr); + req.size = cpu_to_be32(msgs[1].len); + req.buffer_ra = cpu_to_be64(__pa(msgs[1].buf)); + break; + default: + return -EOPNOTSUPP; + } + + rc = i2c_opal_send_request(opal_id, &req); + if (rc) + return rc; + + return num; +} + +static int i2c_opal_smbus_xfer(struct i2c_adapter *adap, u16 addr, + unsigned short flags, char read_write, + u8 command, int size, union i2c_smbus_data *data) +{ + unsigned long opal_id = (unsigned long)adap->algo_data; + struct opal_i2c_request req; + u8 local[2]; + int rc; + + memset(&req, 0, sizeof(req)); + + req.addr = cpu_to_be16(addr); + switch (size) { + case I2C_SMBUS_BYTE: + req.buffer_ra = cpu_to_be64(__pa(&data->byte)); + req.size = cpu_to_be32(1); + /* Fall through */ + case I2C_SMBUS_QUICK: + req.type = (read_write == I2C_SMBUS_READ) ? + OPAL_I2C_RAW_READ : OPAL_I2C_RAW_WRITE; + break; + case I2C_SMBUS_BYTE_DATA: + req.buffer_ra = cpu_to_be64(__pa(&data->byte)); + req.size = cpu_to_be32(1); + req.subaddr = cpu_to_be32(command); + req.subaddr_sz = 1; + req.type = (read_write == I2C_SMBUS_READ) ? + OPAL_I2C_SM_READ : OPAL_I2C_SM_WRITE; + break; + case I2C_SMBUS_WORD_DATA: + if (!read_write) { + local[0] = data->word & 0xff; + local[1] = (data->word >> 8) & 0xff; + } + req.buffer_ra = cpu_to_be64(__pa(local)); + req.size = cpu_to_be32(2); + req.subaddr = cpu_to_be32(command); + req.subaddr_sz = 1; + req.type = (read_write == I2C_SMBUS_READ) ? + OPAL_I2C_SM_READ : OPAL_I2C_SM_WRITE; + break; + case I2C_SMBUS_I2C_BLOCK_DATA: + req.buffer_ra = cpu_to_be64(__pa(&data->block[1])); + req.size = cpu_to_be32(data->block[0]); + req.subaddr = cpu_to_be32(command); + req.subaddr_sz = 1; + req.type = (read_write == I2C_SMBUS_READ) ? + OPAL_I2C_SM_READ : OPAL_I2C_SM_WRITE; + break; + default: + return -EINVAL; + } + + rc = i2c_opal_send_request(opal_id, &req); + if (!rc && read_write && size == I2C_SMBUS_WORD_DATA) { + data->word = ((u16)local[1]) << 8; + data->word |= local[0]; + } + + return rc; +} + +static u32 i2c_opal_func(struct i2c_adapter *adapter) +{ + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE | + I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA | + I2C_FUNC_SMBUS_I2C_BLOCK; +} + +static const struct i2c_algorithm i2c_opal_algo = { + .master_xfer = i2c_opal_master_xfer, + .smbus_xfer = i2c_opal_smbus_xfer, + .functionality = i2c_opal_func, +}; + +static int i2c_opal_probe(struct platform_device *pdev) +{ + struct i2c_adapter *adapter; + const char *pname; + u32 opal_id; + int rc; + + if (!pdev->dev.of_node) + return -ENODEV; + + rc = of_property_read_u32(pdev->dev.of_node, "ibm,opal-id", &opal_id); + if (rc) { + dev_err(&pdev->dev, "Missing ibm,opal-id property !\n"); + return -EIO; + } + + adapter = devm_kzalloc(&pdev->dev, sizeof(*adapter), GFP_KERNEL); + if (!adapter) + return -ENOMEM; + + adapter->algo = &i2c_opal_algo; + adapter->algo_data = (void *)(unsigned long)opal_id; + adapter->dev.parent = &pdev->dev; + adapter->dev.of_node = of_node_get(pdev->dev.of_node); + pname = of_get_property(pdev->dev.of_node, "ibm,port-name", NULL); + if (pname) + strlcpy(adapter->name, pname, sizeof(adapter->name)); + else + strlcpy(adapter->name, "opal", sizeof(adapter->name)); + + platform_set_drvdata(pdev, adapter); + rc = i2c_add_adapter(adapter); + if (rc) + dev_err(&pdev->dev, "Failed to register the i2c adapter\n"); + + return rc; +} + +static int i2c_opal_remove(struct platform_device *pdev) +{ + struct i2c_adapter *adapter = platform_get_drvdata(pdev); + + i2c_del_adapter(adapter); + + return 0; +} + +static const struct of_device_id i2c_opal_of_match[] = { + { + .compatible = "ibm,opal-i2c", + }, + { } +}; +MODULE_DEVICE_TABLE(of, i2c_opal_of_match); + +static struct platform_driver i2c_opal_driver = { + .probe = i2c_opal_probe, + .remove = i2c_opal_remove, + .driver = { + .name = "i2c-opal", + .of_match_table = i2c_opal_of_match, + }, +}; + +static int __init i2c_opal_init(void) +{ + if (!firmware_has_feature(FW_FEATURE_OPAL)) + return -ENODEV; + + return platform_driver_register(&i2c_opal_driver); +} +module_init(i2c_opal_init); + +static void __exit i2c_opal_exit(void) +{ + return platform_driver_unregister(&i2c_opal_driver); +} +module_exit(i2c_opal_exit); + +MODULE_AUTHOR("Neelesh Gupta <neelegup@linux.vnet.ibm.com>"); +MODULE_DESCRIPTION("IBM OPAL I2C driver"); +MODULE_LICENSE("GPL"); |
