Messages in this thread Patch in this message | | | From | Parshuram Thombare <> | Subject | [PATCH v1 2/3] i3c: add mastership handover support to i3c master subsystem | Date | Tue, 7 Apr 2020 00:21:43 +0200 |
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This patch adds mastership handover support to I3C master subsystem as per MIPI I3C v1.0 specification.
Signed-off-by: Parshuram Thombare <pthombar@cadence.com> --- drivers/i3c/master.c | 486 ++++++++++++++++++++++++++++++++++--- include/linux/i3c/master.h | 40 +++ 2 files changed, 487 insertions(+), 39 deletions(-)
diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c index 0ec332e45737..42b6385fc3c8 100644 --- a/drivers/i3c/master.c +++ b/drivers/i3c/master.c @@ -963,6 +963,33 @@ int i3c_master_defslvs_locked(struct i3c_master_controller *master) } EXPORT_SYMBOL_GPL(i3c_master_defslvs_locked); +static int i3c_master_get_accmst_locked(struct i3c_master_controller *master, + u8 addr) +{ + struct i3c_ccc_getaccmst *accmst; + struct i3c_ccc_cmd_dest dest; + struct i3c_ccc_cmd cmd; + int ret; + + accmst = i3c_ccc_cmd_dest_init(&dest, addr, sizeof(*accmst)); + if (!accmst) + return -ENOMEM; + + i3c_ccc_cmd_init(&cmd, true, I3C_CCC_GETACCMST, &dest, 1); + + ret = i3c_master_send_ccc_cmd_locked(master, &cmd); + if (ret) + goto out; + + if (dest.payload.len != sizeof(*accmst)) + ret = -EIO; + +out: + i3c_ccc_cmd_dest_cleanup(&dest); + + return ret; +} + static int i3c_master_setda_locked(struct i3c_master_controller *master, u8 oldaddr, u8 newaddr, bool setdasa) { @@ -1525,6 +1552,185 @@ int i3c_master_do_daa(struct i3c_master_controller *master) } EXPORT_SYMBOL_GPL(i3c_master_do_daa); +static int i3c_master_getaccmst(struct i3c_master_controller *master) +{ + int ret; + + i3c_bus_maintenance_lock(&master->bus); + ret = i3c_master_get_accmst_locked(master, master->mr_addr); + i3c_bus_maintenance_unlock(&master->bus); + + return ret; +} + +static int i3c_master_request_mastership(struct i3c_master_controller *master) +{ + int ret; + + /* request_mastership callback should handle EN/DIS EC MR.*/ + i3c_bus_maintenance_lock(&master->bus); + ret = master->ops->request_mastership(master); + i3c_bus_maintenance_unlock(&master->bus); + + return ret; +} + +static void i3c_mst_yield_bus(struct work_struct *work) +{ + struct i3c_master_controller *m; + struct i3c_dev_desc *i3cdev; + int ret; + + m = container_of(work, struct i3c_master_controller, mst_work); + switch (m->mr_state) { + case I3C_MR_DISEC_MR: + /* + * Disable MR on all but the secondary master first + * reaching here. + */ + i3c_bus_for_each_i3cdev(&m->bus, i3cdev) { + if (I3C_BCR_DEVICE_ROLE(i3cdev->info.bcr) != + I3C_BCR_I3C_MASTER || + i3cdev->info.dyn_addr == m->mr_addr || + m->this == i3cdev) + continue; + i3c_bus_maintenance_lock(&m->bus); + i3c_master_disec_locked(m, i3cdev->info.dyn_addr, + I3C_CCC_EVENT_MR); + i3c_bus_maintenance_unlock(&m->bus); + } + m->mr_state = I3C_MR_GETACCMST; + queue_work(m->wq, &m->mst_work); + break; + + case I3C_MR_GETACCMST: + ret = i3c_master_getaccmst(m); + if (!ret) + m->mr_state = I3C_MR_DONE; + else + m->mr_state = I3C_MR_FAILED; + queue_work(m->wq, &m->mst_work); + break; + + case I3C_MR_DONE: + i3c_bus_for_each_i3cdev(&m->bus, i3cdev) { + if (m->mr_addr == i3cdev->info.dyn_addr) { + m->bus.cur_master = i3cdev; + break; + } + } + m->mr_state = I3C_MR_IDLE; + break; + + case I3C_MR_FAILED: + m->ops->enable_mr_events(m); + i3c_bus_maintenance_lock(&m->bus); + i3c_master_enec_locked(m, I3C_BROADCAST_ADDR, + I3C_CCC_EVENT_MR); + i3c_bus_maintenance_unlock(&m->bus); + m->mr_state = I3C_MR_IDLE; + break; + + default: + break; + } +} + +void +i3c_master_yield_bus(struct i3c_master_controller *master, u8 sec_mst_dyn_addr) +{ + master->ops->disable_mr_events(master); + master->mr_addr = sec_mst_dyn_addr; + master->mr_state = I3C_MR_DISEC_MR; + queue_work(master->wq, &master->mst_work); +} +EXPORT_SYMBOL_GPL(i3c_master_yield_bus); + +static void i3c_sec_mst_acquire_bus(struct work_struct *work) +{ + struct i3c_master_controller *m; + struct i3c_bus *i3cbus; + int ret; + + m = container_of(work, struct i3c_master_controller, sec_mst_work); + i3cbus = i3c_master_get_bus(m); + switch (m->mr_state) { + case I3C_MR_WAIT_DA: + /* Wait until this master have dynamic address */ + if (m->ops->check_event_set(m, I3C_SLV_DA_UPDATE)) + m->mr_state = I3C_MR_REQUEST; + queue_work(m->wq, &m->sec_mst_work); + break; + + case I3C_MR_REQUEST: + /* Wait until we can send MR */ + ret = i3c_master_request_mastership(m); + if (!ret) + m->mr_state = I3C_MR_WAIT_DEFSLVS; + queue_work(m->wq, &m->sec_mst_work); + break; + + case I3C_MR_WAIT_DEFSLVS: + /* + * Wait for DEFSLVS, this event check should make sure + * that DEFSLVS list is read into m->defslvs_data + */ + if (m->ops->check_event_set(m, I3C_SLV_DEFSLVS_CCC)) + m->mr_state = I3C_MR_WAIT_MR_DONE; + queue_work(m->wq, &m->sec_mst_work); + break; + + case I3C_MR_WAIT_MR_DONE: + if (m->ops->check_event_set(m, I3C_SLV_MR_DONE)) { + m->mr_state = I3C_MR_DONE; + complete(&m->mr_comp); + } else { + queue_work(m->wq, &m->sec_mst_work); + } + break; + + default: + m->mr_state = I3C_MR_FAILED; + complete(&m->mr_comp); + break; + } +} + +void i3c_sec_mst_mr_dis_event(struct i3c_master_controller *m) +{ + if (m->mr_state != I3C_MR_IDLE) + m->mr_state = I3C_MR_WAIT_DA; +} +EXPORT_SYMBOL_GPL(i3c_sec_mst_mr_dis_event); + +static int i3c_master_acquire_bus(struct i3c_master_controller *master) +{ + int ret = 0; + + if (!master->this || master->this != master->bus.cur_master) { + i3c_bus_normaluse_lock(&master->bus); + if (master->mr_state == I3C_MR_IDLE) { + master->mr_state = I3C_MR_WAIT_DA; + i3c_bus_normaluse_unlock(&master->bus); + init_completion(&master->mr_comp); + queue_work(master->wq, &master->sec_mst_work); + wait_for_completion(&master->mr_comp); + if (master->mr_state != I3C_MR_DONE) + ret = -EAGAIN; + master->mr_state = I3C_MR_IDLE; + } else { + /* + * MR request is already in process for + * this master + */ + ret = -EAGAIN; + i3c_bus_normaluse_unlock(&master->bus); + } + } + + return ret; +} + /** * i3c_master_set_info() - set master device information * @master: master used to send frames on the bus @@ -1558,10 +1764,6 @@ int i3c_master_set_info(struct i3c_master_controller *master, if (!i3c_bus_dev_addr_is_avail(&master->bus, info->dyn_addr)) return -EINVAL; - if (I3C_BCR_DEVICE_ROLE(info->bcr) == I3C_BCR_I3C_MASTER && - master->secondary) - return -EINVAL; - if (master->this) return -EINVAL; @@ -1622,9 +1824,10 @@ static void i3c_master_detach_free_devs(struct i3c_master_controller *master) * 1. Attach I2C and statically defined I3C devs to the master so that the * master can fill its internal device table appropriately * - * 2. Call &i3c_master_controller_ops->bus_init() method to initialize - * the master controller. That's usually where the bus mode is selected - * (pure bus or mixed fast/slow bus) + * 2. Should have called &i3c_master_controller_ops->bus_init() + * method with pure bus mode to initialize the master controller. + * That's usually where the bus mode is selected (pure bus or + * mixed fast/slow bus) * * 3. Instruct all devices on the bus to drop their dynamic address. This is * particularly important when the bus was previously configured by someone @@ -1708,14 +1911,6 @@ static int i3c_master_bus_init(struct i3c_master_controller *master) } } - /* - * Now execute the controller specific ->bus_init() routine, which - * might configure its internal logic to match the bus limitations. - */ - ret = master->ops->bus_init(master); - if (ret) - goto err_detach_devs; - ret = master->ops->master_set_info(master); if (ret) goto err_detach_devs; @@ -1728,7 +1923,7 @@ static int i3c_master_bus_init(struct i3c_master_controller *master) dev_err(&master->dev, "master_set_info() was not called in ->bus_init()\n"); ret = -EINVAL; - goto err_bus_cleanup; + goto err_detach_devs; } /* @@ -1737,14 +1932,14 @@ static int i3c_master_bus_init(struct i3c_master_controller *master) */ ret = i3c_master_rstdaa_locked(master, I3C_BROADCAST_ADDR); if (ret && ret != I3C_ERROR_M2) - goto err_bus_cleanup; + goto err_detach_devs; /* Disable all slave events before starting DAA. */ ret = i3c_master_disec_locked(master, I3C_BROADCAST_ADDR, I3C_CCC_EVENT_SIR | I3C_CCC_EVENT_MR | I3C_CCC_EVENT_HJ); if (ret && ret != I3C_ERROR_M2) - goto err_bus_cleanup; + goto err_detach_devs; /* * Pre-assign dynamic address and retrieve device information if @@ -1762,10 +1957,6 @@ static int i3c_master_bus_init(struct i3c_master_controller *master) err_rstdaa: i3c_master_rstdaa_locked(master, I3C_BROADCAST_ADDR); -err_bus_cleanup: - if (master->ops->bus_cleanup) - master->ops->bus_cleanup(master); - err_detach_devs: i3c_master_detach_free_devs(master); @@ -2249,6 +2440,9 @@ void i3c_generic_ibi_free_pool(struct i3c_generic_ibi_pool *pool) struct i3c_generic_ibi_slot *slot; unsigned int nslots = 0; + if (!pool) + return; + while (!list_empty(&pool->free_slots)) { slot = list_first_entry(&pool->free_slots, struct i3c_generic_ibi_slot, node); @@ -2392,9 +2586,179 @@ static int i3c_master_check_ops(const struct i3c_master_controller_ops *ops) !ops->recycle_ibi_slot)) return -EINVAL; + if (ops->request_mastership && + (!ops->enable_mr_events || !ops->disable_mr_events || + !ops->check_event_set)) + return -EINVAL; + return 0; } +static struct i2c_dev_boardinfo * +i3c_master_alloc_i2c_boardinfo(struct i3c_master_controller *master, + u16 addr, u8 lvr) +{ + struct i2c_dev_boardinfo *i2cboardinfo; + + i2cboardinfo = kzalloc(sizeof(*i2cboardinfo), GFP_KERNEL); + if (!i2cboardinfo) + return ERR_PTR(-ENOMEM); + + i2cboardinfo->base.addr = addr; + i2cboardinfo->lvr = lvr; + + return i2cboardinfo; +} + +static int i3c_secondary_master_bus_init(struct i3c_master_controller *master) +{ + struct i3c_ccc_dev_desc *desc; + struct i3c_dev_desc *i3cdev; + struct i2c_dev_desc *i2cdev; + struct i2c_dev_boardinfo *info; + int ret, slot; + + desc = master->defslvs_data.devs; + for (slot = 1; slot <= master->defslvs_data.ndevs; slot++, desc++) { + if (desc->static_addr) { + i3c_bus_set_addr_slot_status(&master->bus, + desc->static_addr, + I3C_ADDR_SLOT_I2C_DEV); + info = i3c_master_alloc_i2c_boardinfo(master, + desc->static_addr, + desc->lvr); + if (IS_ERR(info)) { + ret = PTR_ERR(info); + goto err_detach_devs; + } + + i2cdev = i3c_master_alloc_i2c_dev(master, info); + if (IS_ERR(i2cdev)) { + ret = PTR_ERR(i2cdev); + goto err_detach_devs; + } + + ret = i3c_master_attach_i2c_dev(master, i2cdev); + if (ret) { + i3c_master_free_i2c_dev(i2cdev); + goto err_detach_devs; + } + } else { + struct i3c_device_info info = { + .dyn_addr = desc->dyn_addr, + }; + + i3cdev = i3c_master_alloc_i3c_dev(master, &info); + if (IS_ERR(i3cdev)) { + ret = PTR_ERR(i3cdev); + goto err_detach_devs; + } + + ret = i3c_master_attach_i3c_dev(master, i3cdev); + if (ret) { + i3c_master_free_i3c_dev(i3cdev); + goto err_detach_devs; + } + } + } + + ret = master->ops->master_set_info(master); + if (ret) + goto err_bus_cleanup; + + i3c_bus_for_each_i3cdev(&master->bus, i3cdev) { + if (master->this != i3cdev) { + ret = i3c_master_retrieve_dev_info(i3cdev); + if (ret) + goto err_bus_cleanup; + } + } + + if (!master->this) { + dev_err(&master->dev, + "master_set_info() was not called in ->bus_init()\n"); + ret = -EINVAL; + goto err_bus_cleanup; + } + + return 0; + +err_bus_cleanup: + if (master->ops->bus_cleanup) + master->ops->bus_cleanup(master); + +err_detach_devs: + i3c_master_detach_free_devs(master); + + return ret; +} + +static void i3c_secondary_master_register(struct work_struct *work) +{ + struct i3c_master_controller *master; + struct i3c_bus *i3cbus; + int ret; + + master = container_of(work, struct i3c_master_controller, + sec_mst_register_work); + i3cbus = i3c_master_get_bus(master); + + ret = i3c_master_acquire_bus(master); + if (ret) + goto err_cleanup_bus; + + /* Again bus_init to bus_mode, based on data received in DEFSLVS */ + ret = i3c_bus_set_mode(i3cbus, master->defslvs_data.bus_mode); + if (ret) + goto err_cleanup_bus; + + ret = master->ops->bus_init(master); + if (ret) + goto err_cleanup_bus; + + ret = i3c_secondary_master_bus_init(master); + if (ret) + goto err_cleanup_bus; + + ret = device_add(&master->dev); + if (ret) + goto err_cleanup_bus; + + /* + * Expose our I3C bus as an I2C adapter so that I2C devices are exposed + * through the I2C subsystem. + */ + ret = i3c_master_i2c_adapter_init(master); + if (ret) + goto err_del_dev; + + /* + * We're done initializing the bus and the controller, we can now + * register I3C devices from defslvs list. + */ + master->init_done = true; + i3c_bus_normaluse_lock(&master->bus); + i3c_master_register_new_i3c_devs(master); + i3c_bus_normaluse_unlock(&master->bus); + + master->ops->enable_mr_events(master); + i3c_bus_maintenance_lock(&master->bus); + ret = i3c_master_enec_locked(master, I3C_BROADCAST_ADDR, + I3C_CCC_EVENT_MR); + i3c_bus_maintenance_unlock(&master->bus); + + return; + +err_del_dev: + device_del(&master->dev); + +err_cleanup_bus: + if (master->ops->bus_cleanup) + master->ops->bus_cleanup(master); + + put_device(&master->dev); +} + /** * i3c_master_register() - register an I3C master * @master: master used to send frames on the bus @@ -2424,10 +2788,10 @@ int i3c_master_register(struct i3c_master_controller *master, struct i3c_bus *i3cbus = i3c_master_get_bus(master); enum i3c_bus_mode mode = I3C_BUS_MODE_PURE; struct i2c_dev_boardinfo *i2cbi; - int ret; + int ret, sz; - /* We do not support secondary masters yet. */ - if (secondary) + /*Check if controller driver supports secondary masters. */ + if (secondary && !ops->request_mastership) return -ENOTSUPP; ret = i3c_master_check_ops(ops); @@ -2451,10 +2815,45 @@ int i3c_master_register(struct i3c_master_controller *master, device_initialize(&master->dev); dev_set_name(&master->dev, "i3c-%d", i3cbus->id); - ret = of_populate_i3c_bus(master); + master->wq = alloc_workqueue("%s", 0, 0, dev_name(parent)); + if (!master->wq) { + ret = -ENOMEM; + goto err_put_dev; + } + + master->mr_state = I3C_MR_IDLE; + INIT_WORK(&master->sec_mst_work, i3c_sec_mst_acquire_bus); + INIT_WORK(&master->mst_work, i3c_mst_yield_bus); + + ret = i3c_bus_set_mode(i3cbus, mode); + if (ret) + goto err_put_dev; + + /* + * Now execute the controller specific ->bus_init() routine, which + * might configure its internal logic to match the bus limitations. + */ + ret = master->ops->bus_init(master); if (ret) goto err_put_dev; + if (secondary) { + sz = sizeof(struct i3c_ccc_dev_desc) * I3C_BUS_MAX_DEVS; + master->defslvs_data.devs = devm_kzalloc(&master->dev, sz, + GFP_KERNEL); + if (!master->defslvs_data.devs) + goto err_put_dev; + + INIT_WORK(&master->sec_mst_register_work, + i3c_secondary_master_register); + queue_work(master->wq, &master->sec_mst_register_work); + return 0; + } + + ret = of_populate_i3c_bus(master); + if (ret) + goto err_cleanup_bus; + list_for_each_entry(i2cbi, &master->boardinfo.i2c, node) { switch (i2cbi->lvr & I3C_LVR_I2C_INDEX_MASK) { case I3C_LVR_I2C_INDEX(0): @@ -2468,23 +2867,13 @@ int i3c_master_register(struct i3c_master_controller *master, break; default: ret = -EINVAL; - goto err_put_dev; + goto err_cleanup_bus; } } - ret = i3c_bus_set_mode(i3cbus, mode); - if (ret) - goto err_put_dev; - - master->wq = alloc_workqueue("%s", 0, 0, dev_name(parent)); - if (!master->wq) { - ret = -ENOMEM; - goto err_put_dev; - } - ret = i3c_master_bus_init(master); if (ret) - goto err_put_dev; + goto err_cleanup_bus; ret = device_add(&master->dev); if (ret) @@ -2507,6 +2896,22 @@ int i3c_master_register(struct i3c_master_controller *master, i3c_master_register_new_i3c_devs(master); i3c_bus_normaluse_unlock(&master->bus); + if (ops->request_mastership) { + master->ops->enable_mr_events(master); + i3c_bus_maintenance_lock(&master->bus); + i3c_master_enec_locked(master, I3C_BROADCAST_ADDR, + I3C_CCC_EVENT_MR); + i3c_bus_maintenance_unlock(&master->bus); + } + + ret = i3c_bus_set_mode(i3cbus, mode); + if (ret) + goto err_del_dev; + + ret = master->ops->bus_init(master); + if (ret) + goto err_del_dev; + return 0; err_del_dev: @@ -2557,7 +2962,10 @@ int i3c_dev_do_priv_xfers_locked(struct i3c_dev_desc *dev, if (!master->ops->priv_xfers) return -ENOTSUPP; - return master->ops->priv_xfers(dev, xfers, nxfers); + if (!i3c_master_acquire_bus(master)) + return master->ops->priv_xfers(dev, xfers, nxfers); + else + return -EAGAIN; } int i3c_dev_disable_ibi_locked(struct i3c_dev_desc *dev) diff --git a/include/linux/i3c/master.h b/include/linux/i3c/master.h index 3dc7eafe811a..c6427c62ed83 100644 --- a/include/linux/i3c/master.h +++ b/include/linux/i3c/master.h @@ -259,6 +259,27 @@ enum i3c_bus_mode { I3C_BUS_MODE_MIXED_SLOW, }; +enum i3c_mr_state { + I3C_MR_IDLE, + I3C_MR_DISEC_MR, + I3C_MR_SEND_DEFSLVS, + I3C_MR_GETACCMST, + I3C_MR_WAIT_DA, + I3C_MR_CHECK_STATE, + I3C_MR_REQUEST, + I3C_MR_WAIT_DEFSLVS, + I3C_MR_WAIT_MR_DONE, + I3C_MR_DONE, + I3C_MR_FAILED, +}; + +enum i3c_event { + I3C_SLV_DA_UPDATE, + I3C_SLV_DEFSLVS_CCC, + I3C_SLV_MR_DIS, + I3C_SLV_MR_DONE, +}; + /** * enum i3c_addr_slot_status - I3C address slot status * @I3C_ADDR_SLOT_FREE: address is free @@ -448,6 +469,11 @@ struct i3c_master_controller_ops { int (*disable_ibi)(struct i3c_dev_desc *dev); void (*recycle_ibi_slot)(struct i3c_dev_desc *dev, struct i3c_ibi_slot *slot); + int (*request_mastership)(struct i3c_master_controller *master); + void (*enable_mr_events)(struct i3c_master_controller *m); + void (*disable_mr_events)(struct i3c_master_controller *m); + bool (*check_event_set)(struct i3c_master_controller *m, + enum i3c_event); }; /** @@ -489,6 +515,17 @@ struct i3c_master_controller { } boardinfo; struct i3c_bus bus; struct workqueue_struct *wq; + struct work_struct sec_mst_register_work; + struct work_struct mst_work; + struct work_struct sec_mst_work; + struct completion mr_comp; + enum i3c_mr_state mr_state; + u8 mr_addr; + struct { + u32 ndevs; + enum i3c_bus_mode bus_mode; + struct i3c_ccc_dev_desc *devs; + } defslvs_data; }; /** @@ -513,6 +550,9 @@ struct i3c_master_controller { #define i3c_bus_for_each_i3cdev(bus, dev) \ list_for_each_entry(dev, &(bus)->devs.i3c, common.node) +void i3c_master_yield_bus(struct i3c_master_controller *master, + u8 slv_dyn_addr); +void i3c_sec_mst_mr_dis_event(struct i3c_master_controller *m); int i3c_master_do_i2c_xfers(struct i3c_master_controller *master, const struct i2c_msg *xfers, int nxfers); -- 2.17.1
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