From: "Edward A. James" <eaja...@us.ibm.com> For the P8 OCC, add the procedure to send a command to the OCC over I2C bus. This involves writing the OCC command registers with serial communication operations (SCOMs) interpreted by the I2C slave. For the P9 OCC, add a procedure to use the OCC in-kernel API to send a command to the OCC through the SBE engine.
Signed-off-by: Edward A. James <eaja...@us.ibm.com> --- drivers/hwmon/occ/p8_i2c.c | 185 ++++++++++++++++++++++++++++++++++++++++++++- drivers/hwmon/occ/p9_sbe.c | 95 ++++++++++++++++++++++- 2 files changed, 278 insertions(+), 2 deletions(-) diff --git a/drivers/hwmon/occ/p8_i2c.c b/drivers/hwmon/occ/p8_i2c.c index 025471f..8032c0b 100644 --- a/drivers/hwmon/occ/p8_i2c.c +++ b/drivers/hwmon/occ/p8_i2c.c @@ -9,11 +9,29 @@ #include <linux/device.h> #include <linux/errno.h> +#include <linux/fsi-occ.h> #include <linux/i2c.h> +#include <linux/jiffies.h> #include <linux/module.h> +#include <linux/sched.h> +#include <asm/unaligned.h> #include "common.h" +#define OCC_TIMEOUT_MS 1000 +#define OCC_CMD_IN_PRG_WAIT_MS 50 + +/* OCB (on-chip control bridge - interface to OCC) registers */ +#define OCB_DATA1 0x6B035 +#define OCB_ADDR 0x6B070 +#define OCB_DATA3 0x6B075 + +/* OCC SRAM address space */ +#define OCC_SRAM_ADDR_CMD 0xFFFF6000 +#define OCC_SRAM_ADDR_RESP 0xFFFF7000 + +#define OCC_DATA_ATTN 0x20010000 + struct p8_i2c_occ { struct occ occ; struct i2c_client *client; @@ -21,9 +39,174 @@ struct p8_i2c_occ { #define to_p8_i2c_occ(x) container_of((x), struct p8_i2c_occ, occ) +static int p8_i2c_occ_getscom(struct i2c_client *client, u32 address, u8 *data) +{ + ssize_t rc; + __be64 buf; + struct i2c_msg msgs[2]; + + /* p8 i2c slave requires shift */ + address <<= 1; + + msgs[0].addr = client->addr; + msgs[0].flags = client->flags & I2C_M_TEN; + msgs[0].len = sizeof(u32); + /* address is a scom address; bus-endian */ + msgs[0].buf = (char *)&address; + + /* data from OCC is big-endian */ + msgs[1].addr = client->addr; + msgs[1].flags = (client->flags & I2C_M_TEN) | I2C_M_RD; + msgs[1].len = sizeof(u64); + msgs[1].buf = (char *)&buf; + + rc = i2c_transfer(client->adapter, msgs, 2); + if (rc < 0) + return rc; + + *(u64 *)data = be64_to_cpu(buf); + + return 0; +} + +static int p8_i2c_occ_putscom(struct i2c_client *client, u32 address, u8 *data) +{ + u32 buf[3]; + ssize_t rc; + + /* p8 i2c slave requires shift */ + address <<= 1; + + /* address is bus-endian; data passed through from user as-is */ + buf[0] = address; + memcpy(&buf[1], &data[4], sizeof(u32)); + memcpy(&buf[2], data, sizeof(u32)); + + rc = i2c_master_send(client, (const char *)buf, sizeof(buf)); + if (rc < 0) + return rc; + else if (rc != sizeof(buf)) + return -EIO; + + return 0; +} + +static int p8_i2c_occ_putscom_u32(struct i2c_client *client, u32 address, + u32 data0, u32 data1) +{ + u8 buf[8]; + + memcpy(buf, &data0, 4); + memcpy(buf + 4, &data1, 4); + + return p8_i2c_occ_putscom(client, address, buf); +} + +static int p8_i2c_occ_putscom_be(struct i2c_client *client, u32 address, + u8 *data) +{ + __be32 data0, data1; + + memcpy(&data0, data, 4); + memcpy(&data1, data + 4, 4); + + return p8_i2c_occ_putscom_u32(client, address, be32_to_cpu(data0), + be32_to_cpu(data1)); +} + static int p8_i2c_occ_send_cmd(struct occ *occ, u8 *cmd) { - return -EOPNOTSUPP; + int i, rc; + unsigned long start; + u16 data_length; + const unsigned long timeout = msecs_to_jiffies(OCC_TIMEOUT_MS); + const long int wait_time = msecs_to_jiffies(OCC_CMD_IN_PRG_WAIT_MS); + struct p8_i2c_occ *p8_i2c_occ = to_p8_i2c_occ(occ); + struct i2c_client *client = p8_i2c_occ->client; + struct occ_response *resp = &occ->resp; + + start = jiffies; + + /* set sram address for command */ + rc = p8_i2c_occ_putscom_u32(client, OCB_ADDR, OCC_SRAM_ADDR_CMD, 0); + if (rc) + return rc; + + /* write command (expected to already be BE), we need bus-endian... */ + rc = p8_i2c_occ_putscom_be(client, OCB_DATA3, cmd); + if (rc) + return rc; + + /* trigger OCC attention */ + rc = p8_i2c_occ_putscom_u32(client, OCB_DATA1, OCC_DATA_ATTN, 0); + if (rc) + return rc; + + do { + /* set sram address for response */ + rc = p8_i2c_occ_putscom_u32(client, OCB_ADDR, + OCC_SRAM_ADDR_RESP, 0); + if (rc) + return rc; + + rc = p8_i2c_occ_getscom(client, OCB_DATA3, (u8 *)resp); + if (rc) + return rc; + + /* wait for OCC */ + if (resp->return_status == OCC_RESP_CMD_IN_PRG) { + rc = -EALREADY; + + if (time_after(jiffies, start + timeout)) + break; + + set_current_state(TASK_INTERRUPTIBLE); + schedule_timeout(wait_time); + } + } while (rc); + + /* check the OCC response */ + switch (resp->return_status) { + case OCC_RESP_CMD_IN_PRG: + rc = -ETIMEDOUT; + break; + case OCC_RESP_SUCCESS: + rc = 0; + break; + case OCC_RESP_CMD_INVAL: + case OCC_RESP_CMD_LEN_INVAL: + case OCC_RESP_DATA_INVAL: + case OCC_RESP_CHKSUM_ERR: + rc = -EINVAL; + break; + case OCC_RESP_INT_ERR: + case OCC_RESP_BAD_STATE: + case OCC_RESP_CRIT_EXCEPT: + case OCC_RESP_CRIT_INIT: + case OCC_RESP_CRIT_WATCHDOG: + case OCC_RESP_CRIT_OCB: + case OCC_RESP_CRIT_HW: + rc = -EREMOTEIO; + break; + default: + rc = -EPROTO; + } + + if (rc < 0) + return rc; + + data_length = get_unaligned_be16(&resp->data_length); + if (data_length > OCC_RESP_DATA_BYTES) + return -EMSGSIZE; + + /* fetch the rest of the response data */ + for (i = 8; i < data_length + 7; i += 8) { + rc = p8_i2c_occ_getscom(client, OCB_DATA3, ((u8 *)resp) + i); + if (rc) + return rc; + } + + return 0; } static int p8_i2c_occ_probe(struct i2c_client *client, diff --git a/drivers/hwmon/occ/p9_sbe.c b/drivers/hwmon/occ/p9_sbe.c index 58c3bb2..be3a469 100644 --- a/drivers/hwmon/occ/p9_sbe.c +++ b/drivers/hwmon/occ/p9_sbe.c @@ -9,21 +9,102 @@ #include <linux/device.h> #include <linux/errno.h> +#include <linux/fsi-occ.h> #include <linux/module.h> #include <linux/platform_device.h> +#include <linux/spinlock.h> #include "common.h" struct p9_sbe_occ { struct occ occ; struct device *sbe; + + /* + * Pointer to occ device client. We store this so that we can cancel + * the client operations in remove() if necessary. We only need one + * pointer since we do one OCC operation (open, write, read, close) at + * a time (access to p9_sbe_occ_send_cmd is locked in the common code + * with occ.lock). + */ + struct occ_client *client; + + /* + * This lock controls access to the client pointer and ensures atomic + * open, close and NULL assignment. This prevents simultaneous opening + * and closing of the client, or closing multiple times. + */ + spinlock_t lock; }; #define to_p9_sbe_occ(x) container_of((x), struct p9_sbe_occ, occ) +static void p9_sbe_occ_close_client(struct p9_sbe_occ *occ) +{ + unsigned long flags; + struct occ_client *tmp_client; + + spin_lock_irqsave(&occ->lock, flags); + tmp_client = occ->client; + occ->client = NULL; + occ_drv_release(tmp_client); + spin_unlock_irqrestore(&occ->lock, flags); +} + static int p9_sbe_occ_send_cmd(struct occ *occ, u8 *cmd) { - return -EOPNOTSUPP; + int rc; + unsigned long flags; + struct occ_response *resp = &occ->resp; + struct p9_sbe_occ *p9_sbe_occ = to_p9_sbe_occ(occ); + + spin_lock_irqsave(&p9_sbe_occ->lock, flags); + if (p9_sbe_occ->sbe) + p9_sbe_occ->client = occ_drv_open(p9_sbe_occ->sbe, 0); + spin_unlock_irqrestore(&p9_sbe_occ->lock, flags); + + if (!p9_sbe_occ->client) + return -ENODEV; + + /* skip first byte (sequence number), OCC driver handles it */ + rc = occ_drv_write(p9_sbe_occ->client, (const char *)&cmd[1], 7); + if (rc < 0) + goto err; + + rc = occ_drv_read(p9_sbe_occ->client, (char *)resp, sizeof(*resp)); + if (rc < 0) + goto err; + + /* check the OCC response */ + switch (resp->return_status) { + case OCC_RESP_CMD_IN_PRG: + rc = -ETIMEDOUT; + break; + case OCC_RESP_SUCCESS: + rc = 0; + break; + case OCC_RESP_CMD_INVAL: + case OCC_RESP_CMD_LEN_INVAL: + case OCC_RESP_DATA_INVAL: + case OCC_RESP_CHKSUM_ERR: + rc = -EINVAL; + break; + case OCC_RESP_INT_ERR: + case OCC_RESP_BAD_STATE: + case OCC_RESP_CRIT_EXCEPT: + case OCC_RESP_CRIT_INIT: + case OCC_RESP_CRIT_WATCHDOG: + case OCC_RESP_CRIT_OCB: + case OCC_RESP_CRIT_HW: + rc = -EREMOTEIO; + break; + default: + rc = -EPROTO; + } + +err: + p9_sbe_occ_close_client(p9_sbe_occ); + return rc; } static int p9_sbe_occ_probe(struct platform_device *pdev) @@ -46,6 +127,17 @@ static int p9_sbe_occ_probe(struct platform_device *pdev) return occ_setup(occ, "p9_occ"); } +static int p9_sbe_occ_remove(struct platform_device *pdev) +{ + struct occ *occ = platform_get_drvdata(pdev); + struct p9_sbe_occ *p9_sbe_occ = to_p9_sbe_occ(occ); + + p9_sbe_occ->sbe = NULL; + p9_sbe_occ_close_client(p9_sbe_occ); + + return 0; +} + static const struct of_device_id p9_sbe_occ_of_match[] = { { .compatible = "ibm,p9-occ-hwmon" }, { }, @@ -57,6 +149,7 @@ static int p9_sbe_occ_probe(struct platform_device *pdev) .of_match_table = p9_sbe_occ_of_match, }, .probe = p9_sbe_occ_probe, + .remove = p9_sbe_occ_remove, }; module_platform_driver(p9_sbe_occ_driver); -- 1.8.3.1