From 2b545cd8e1b2a2bd60d991c7f1b45a30c673ece2 Mon Sep 17 00:00:00 2001 From: Jeremy Kerr Date: Tue, 6 Jun 2017 16:08:42 -0500 Subject: [PATCH] drivers/fsi: Implement slave initialisation Implement fsi_slave_init: if we can read a chip ID, create fsi_slave devices and register with the driver core. Includes changes from Christopher Bostic . Signed-off-by: Jeremy Kerr Signed-off-by: Christopher Bostic Signed-off-by: Joel Stanley Signed-off-by: Greg Kroah-Hartman --- drivers/fsi/Kconfig | 1 + drivers/fsi/fsi-core.c | 67 ++++++++++++++++++++++++++++++++++++++++-- 2 files changed, 66 insertions(+), 2 deletions(-) diff --git a/drivers/fsi/Kconfig b/drivers/fsi/Kconfig index 04c1a0efa7a7..e1006c6808a7 100644 --- a/drivers/fsi/Kconfig +++ b/drivers/fsi/Kconfig @@ -6,6 +6,7 @@ menu "FSI support" config FSI tristate "FSI support" + select CRC4 ---help--- FSI - the FRU Support Interface - is a simple bus for low-level access to POWER-based hardware. diff --git a/drivers/fsi/fsi-core.c b/drivers/fsi/fsi-core.c index 235f17a6d89e..9d9adc17072c 100644 --- a/drivers/fsi/fsi-core.c +++ b/drivers/fsi/fsi-core.c @@ -13,13 +13,17 @@ * GNU General Public License for more details. */ +#include #include #include #include #include +#include #include "fsi-master.h" +#define FSI_SLAVE_SIZE_23b 0x800000 + static DEFINE_IDA(master_ida); struct fsi_slave { @@ -90,11 +94,70 @@ static int fsi_slave_write(struct fsi_slave *slave, uint32_t addr, addr, val, size); } +static void fsi_slave_release(struct device *dev) +{ + struct fsi_slave *slave = to_fsi_slave(dev); + + kfree(slave); +} + static int fsi_slave_init(struct fsi_master *master, int link, uint8_t id) { - /* todo: initialise slave device, perform engine scan */ + struct fsi_slave *slave; + uint32_t chip_id; + uint8_t crc; + int rc; + + /* Currently, we only support single slaves on a link, and use the + * full 23-bit address range + */ + if (id != 0) + return -EINVAL; + + rc = fsi_master_read(master, link, id, 0, &chip_id, sizeof(chip_id)); + if (rc) { + dev_dbg(&master->dev, "can't read slave %02x:%02x %d\n", + link, id, rc); + return -ENODEV; + } + chip_id = be32_to_cpu(chip_id); + + crc = crc4(0, chip_id, 32); + if (crc) { + dev_warn(&master->dev, "slave %02x:%02x invalid chip id CRC!\n", + link, id); + return -EIO; + } + + dev_info(&master->dev, "fsi: found chip %08x at %02x:%02x:%02x\n", + chip_id, master->idx, link, id); + + /* We can communicate with a slave; create the slave device and + * register. + */ + slave = kzalloc(sizeof(*slave), GFP_KERNEL); + if (!slave) + return -ENOMEM; + + slave->master = master; + slave->dev.parent = &master->dev; + slave->dev.release = fsi_slave_release; + slave->link = link; + slave->id = id; + slave->size = FSI_SLAVE_SIZE_23b; + + dev_set_name(&slave->dev, "slave@%02x:%02x", link, id); + rc = device_register(&slave->dev); + if (rc < 0) { + dev_warn(&master->dev, "failed to create slave device: %d\n", + rc); + put_device(&slave->dev); + return rc; + } + + /* todo: perform engine scan */ - return -ENODEV; + return rc; } /* FSI master support */ -- 2.20.1