diff options
Diffstat (limited to 'meta-openbmc-mods/meta-common/recipes-kernel/linux/linux-aspeed/0040-i2c-Add-mux-hold-unhold-msg-types.patch')
| -rw-r--r-- | meta-openbmc-mods/meta-common/recipes-kernel/linux/linux-aspeed/0040-i2c-Add-mux-hold-unhold-msg-types.patch | 488 |
1 files changed, 488 insertions, 0 deletions
diff --git a/meta-openbmc-mods/meta-common/recipes-kernel/linux/linux-aspeed/0040-i2c-Add-mux-hold-unhold-msg-types.patch b/meta-openbmc-mods/meta-common/recipes-kernel/linux/linux-aspeed/0040-i2c-Add-mux-hold-unhold-msg-types.patch new file mode 100644 index 000000000..198beaa93 --- /dev/null +++ b/meta-openbmc-mods/meta-common/recipes-kernel/linux/linux-aspeed/0040-i2c-Add-mux-hold-unhold-msg-types.patch @@ -0,0 +1,488 @@ +From ee9cee93b96b791f52295d7763985fdb10903e2b Mon Sep 17 00:00:00 2001 +From: Jae Hyun Yoo <jae.hyun.yoo@intel.com> +Date: Fri, 15 Feb 2019 16:05:09 -0800 +Subject: [PATCH] i2c: Add mux hold/unhold msg types + +This commit adds mux hold/unhold message types to support extended +mux control for IPMB and MCTP devices. A hold or an unhold message +can be added at the end of I2C message stream wrapped by +repeated-start, also can be used as a single message independantly. + +This mux hold/unhold message will be delivered throughout all mux +levels in the path. Means that if it goes to multi-level mux path, +all muxes will be held/unheld by this message. + +1. Hold message + struct i2c_msg msg; + uint16_t timeout = 5000; // timeout in ms. 5 secs in this example. + + msg.addr = 0x0; // any value can be used. addr will be ignored in this packet. + msg.flags = I2C_M_HOLD; // set this flag to indicate it's a hold message. + msg.len = sizeof(uint16_t); // timeout value will be delivered using two bytes buffer. + msg.buf = (uint8_t *)&timeout; // set timeout value. + +2. Unhold message + struct i2c_msg msg; + uint16_t timeout = 0; // set 0 for an unhold message. + + msg.addr = 0x0; // any value can be used. addr will be ignored in this packet. + msg.flags = I2C_M_HOLD; // set this flag to indicate it's an unhold message. + msg.len = sizeof(uint16_t); // timeout value will be delivered using two bytes buffer. + msg.buf = (uint8_t *)&timeout; // set timeout value. + + This unhold message can be delivered to a mux adapter even when + a bus is locked so that any holding state can be unheld + immediately by invoking this unhold message. + +This patch would not be welcomed from upstream so it should be kept +in downstream only. + +Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo@intel.com> +--- + drivers/i2c/i2c-core-base.c | 70 +++++++++++++++++++++++++-- + drivers/i2c/i2c-core-smbus.c | 22 +++++++-- + drivers/i2c/i2c-mux.c | 109 +++++++++++++++++++++++++++++++++++++++---- + include/linux/i2c-mux.h | 3 ++ + include/linux/i2c.h | 25 ++++++++++ + include/uapi/linux/i2c.h | 1 + + 6 files changed, 214 insertions(+), 16 deletions(-) + +diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c +index 5f6a4985f2bc..d1cd7afe4068 100644 +--- a/drivers/i2c/i2c-core-base.c ++++ b/drivers/i2c/i2c-core-base.c +@@ -1297,6 +1297,25 @@ int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr) + } + EXPORT_SYMBOL_GPL(i2c_handle_smbus_host_notify); + ++static void i2c_adapter_hold(struct i2c_adapter *adapter, unsigned long timeout) ++{ ++ mutex_lock(&adapter->hold_lock); ++ mod_timer(&adapter->hold_timer, jiffies + timeout); ++} ++ ++static void i2c_adapter_unhold(struct i2c_adapter *adapter) ++{ ++ del_timer_sync(&adapter->hold_timer); ++ mutex_unlock(&adapter->hold_lock); ++} ++ ++static void i2c_adapter_hold_timer_callback(struct timer_list *t) ++{ ++ struct i2c_adapter *adapter = from_timer(adapter, t, hold_timer); ++ ++ i2c_adapter_unhold(adapter); ++} ++ + static int i2c_register_adapter(struct i2c_adapter *adap) + { + int res = -EINVAL; +@@ -1379,6 +1398,9 @@ static int i2c_register_adapter(struct i2c_adapter *adap) + bus_for_each_drv(&i2c_bus_type, NULL, adap, __process_new_adapter); + mutex_unlock(&core_lock); + ++ mutex_init(&adap->hold_lock); ++ timer_setup(&adap->hold_timer, i2c_adapter_hold_timer_callback, 0); ++ + return 0; + + out_reg: +@@ -1599,6 +1621,8 @@ void i2c_del_adapter(struct i2c_adapter *adap) + idr_remove(&i2c_adapter_idr, adap->nr); + mutex_unlock(&core_lock); + ++ i2c_adapter_unhold(adap); ++ + /* Clear the device structure in case this adapter is ever going to be + added again */ + memset(&adap->dev, 0, sizeof(adap->dev)); +@@ -1948,7 +1972,9 @@ static int i2c_check_for_quirks(struct i2c_adapter *adap, struct i2c_msg *msgs, + */ + int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) + { ++ enum i2c_hold_msg_type hold_msg = I2C_HOLD_MSG_NONE; + unsigned long orig_jiffies; ++ unsigned long timeout; + int ret, try; + + if (WARN_ON(!msgs || num < 1)) +@@ -1961,6 +1987,25 @@ int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) + if (adap->quirks && i2c_check_for_quirks(adap, msgs, num)) + return -EOPNOTSUPP; + ++ /* Do not deliver a mux hold msg to root bus adapter */ ++ if (!i2c_parent_is_i2c_adapter(adap)) { ++ hold_msg = i2c_check_hold_msg(msgs[num - 1].flags, ++ msgs[num - 1].len, ++ (u16 *)msgs[num - 1].buf); ++ if (hold_msg == I2C_HOLD_MSG_SET) { ++ timeout = msecs_to_jiffies(*(u16 *)msgs[num - 1].buf); ++ i2c_adapter_hold(adap, timeout); ++ ++ if (--num == 0) ++ return 0; ++ } else if (hold_msg == I2C_HOLD_MSG_RESET) { ++ i2c_adapter_unhold(adap); ++ return 0; ++ } else if (hold_msg == I2C_HOLD_MSG_NONE) { ++ mutex_lock(&adap->hold_lock); ++ } ++ } ++ + /* + * i2c_trace_msg_key gets enabled when tracepoint i2c_transfer gets + * enabled. This is an efficient way of keeping the for-loop from +@@ -1997,6 +2042,9 @@ int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) + trace_i2c_result(adap, num, ret); + } + ++ if (!i2c_parent_is_i2c_adapter(adap) && hold_msg == I2C_HOLD_MSG_NONE) ++ mutex_unlock(&adap->hold_lock); ++ + return ret; + } + EXPORT_SYMBOL(__i2c_transfer); +@@ -2015,6 +2063,7 @@ EXPORT_SYMBOL(__i2c_transfer); + */ + int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) + { ++ bool do_bus_lock = true; + int ret; + + if (!adap->algo->master_xfer) { +@@ -2038,12 +2087,25 @@ int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) + * one (discarding status on the second message) or errno + * (discarding status on the first one). + */ +- ret = __i2c_lock_bus_helper(adap); +- if (ret) +- return ret; ++ /* ++ * Do not lock a bus for delivering an unhold msg to a mux ++ * adpater. This is just for a single length unhold msg case. ++ */ ++ if (num == 1 && i2c_parent_is_i2c_adapter(adap) && ++ i2c_check_hold_msg(msgs[0].flags, msgs[0].len, ++ (u16 *)msgs[0].buf) == ++ I2C_HOLD_MSG_RESET) ++ do_bus_lock = false; ++ ++ if (do_bus_lock) { ++ ret = __i2c_lock_bus_helper(adap); ++ if (ret) ++ return ret; ++ } + + ret = __i2c_transfer(adap, msgs, num); +- i2c_unlock_bus(adap, I2C_LOCK_SEGMENT); ++ if (do_bus_lock) ++ i2c_unlock_bus(adap, I2C_LOCK_SEGMENT); + + return ret; + } +diff --git a/drivers/i2c/i2c-core-smbus.c b/drivers/i2c/i2c-core-smbus.c +index 3ac426a8ab5a..f7bf95101e34 100644 +--- a/drivers/i2c/i2c-core-smbus.c ++++ b/drivers/i2c/i2c-core-smbus.c +@@ -526,15 +526,29 @@ s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, + unsigned short flags, char read_write, + u8 command, int protocol, union i2c_smbus_data *data) + { ++ bool do_bus_lock = true; + s32 res; + +- res = __i2c_lock_bus_helper(adapter); +- if (res) +- return res; ++ /* ++ * Do not lock a bus for delivering an unhold msg to a mux adpater. ++ * This is just for a single length unhold msg case. ++ */ ++ if (i2c_parent_is_i2c_adapter(adapter) && ++ i2c_check_hold_msg(flags, ++ protocol == I2C_SMBUS_WORD_DATA ? 2 : 0, ++ &data->word) == I2C_HOLD_MSG_RESET) ++ do_bus_lock = false; ++ ++ if (do_bus_lock) { ++ res = __i2c_lock_bus_helper(adapter); ++ if (res) ++ return res; ++ } + + res = __i2c_smbus_xfer(adapter, addr, flags, read_write, + command, protocol, data); +- i2c_unlock_bus(adapter, I2C_LOCK_SEGMENT); ++ if (do_bus_lock) ++ i2c_unlock_bus(adapter, I2C_LOCK_SEGMENT); + + return res; + } +diff --git a/drivers/i2c/i2c-mux.c b/drivers/i2c/i2c-mux.c +index 774507b54b57..c6e433238b22 100644 +--- a/drivers/i2c/i2c-mux.c ++++ b/drivers/i2c/i2c-mux.c +@@ -27,6 +27,7 @@ + #include <linux/of.h> + #include <linux/slab.h> + #include <linux/sysfs.h> ++#include <linux/timer.h> + + /* multiplexer per channel data */ + struct i2c_mux_priv { +@@ -36,21 +37,57 @@ struct i2c_mux_priv { + u32 chan_id; + }; + ++static void i2c_mux_hold(struct i2c_mux_core *muxc, unsigned long timeout) ++{ ++ mutex_lock(&muxc->hold_lock); ++ mod_timer(&muxc->hold_timer, jiffies + timeout); ++} ++ ++static void i2c_mux_unhold(struct i2c_mux_core *muxc) ++{ ++ del_timer_sync(&muxc->hold_timer); ++ mutex_unlock(&muxc->hold_lock); ++} ++ ++static void i2c_mux_hold_timer_callback(struct timer_list *t) ++{ ++ struct i2c_mux_core *muxc = from_timer(muxc, t, hold_timer); ++ ++ i2c_mux_unhold(muxc); ++} ++ + static int __i2c_mux_master_xfer(struct i2c_adapter *adap, + struct i2c_msg msgs[], int num) + { + struct i2c_mux_priv *priv = adap->algo_data; + struct i2c_mux_core *muxc = priv->muxc; + struct i2c_adapter *parent = muxc->parent; ++ enum i2c_hold_msg_type hold_msg; ++ unsigned long timeout; + int ret; + + /* Switch to the right mux port and perform the transfer. */ + ++ hold_msg = i2c_check_hold_msg(msgs[num - 1].flags, ++ msgs[num - 1].len, ++ (u16 *)msgs[num - 1].buf); ++ if (hold_msg == I2C_HOLD_MSG_SET) { ++ timeout = msecs_to_jiffies(*(u16 *)msgs[num - 1].buf); ++ i2c_mux_hold(muxc, timeout); ++ } else if (hold_msg == I2C_HOLD_MSG_NONE) { ++ mutex_lock(&muxc->hold_lock); ++ } + ret = muxc->select(muxc, priv->chan_id); + if (ret >= 0) + ret = __i2c_transfer(parent, msgs, num); +- if (muxc->deselect) +- muxc->deselect(muxc, priv->chan_id); ++ if (hold_msg != I2C_HOLD_MSG_SET) { ++ if (muxc->deselect) ++ muxc->deselect(muxc, priv->chan_id); ++ if (hold_msg == I2C_HOLD_MSG_RESET) ++ i2c_mux_unhold(muxc); ++ else ++ mutex_unlock(&muxc->hold_lock); ++ } + + return ret; + } +@@ -61,15 +98,32 @@ static int i2c_mux_master_xfer(struct i2c_adapter *adap, + struct i2c_mux_priv *priv = adap->algo_data; + struct i2c_mux_core *muxc = priv->muxc; + struct i2c_adapter *parent = muxc->parent; ++ enum i2c_hold_msg_type hold_msg; ++ unsigned long timeout; + int ret; + + /* Switch to the right mux port and perform the transfer. */ + ++ hold_msg = i2c_check_hold_msg(msgs[num - 1].flags, ++ msgs[num - 1].len, ++ (u16 *)msgs[num - 1].buf); ++ if (hold_msg == I2C_HOLD_MSG_SET) { ++ timeout = msecs_to_jiffies(*(u16 *)msgs[num - 1].buf); ++ i2c_mux_hold(muxc, timeout); ++ } else if (hold_msg == I2C_HOLD_MSG_NONE) { ++ mutex_lock(&muxc->hold_lock); ++ } + ret = muxc->select(muxc, priv->chan_id); + if (ret >= 0) + ret = i2c_transfer(parent, msgs, num); +- if (muxc->deselect) +- muxc->deselect(muxc, priv->chan_id); ++ if (hold_msg != I2C_HOLD_MSG_SET) { ++ if (muxc->deselect) ++ muxc->deselect(muxc, priv->chan_id); ++ if (hold_msg == I2C_HOLD_MSG_RESET) ++ i2c_mux_unhold(muxc); ++ else ++ mutex_unlock(&muxc->hold_lock); ++ } + + return ret; + } +@@ -82,16 +136,33 @@ static int __i2c_mux_smbus_xfer(struct i2c_adapter *adap, + struct i2c_mux_priv *priv = adap->algo_data; + struct i2c_mux_core *muxc = priv->muxc; + struct i2c_adapter *parent = muxc->parent; ++ enum i2c_hold_msg_type hold_msg; ++ unsigned long timeout; + int ret; + + /* Select the right mux port and perform the transfer. */ + ++ hold_msg = i2c_check_hold_msg(flags, ++ size == I2C_SMBUS_WORD_DATA ? 2 : 0, ++ &data->word); ++ if (hold_msg == I2C_HOLD_MSG_SET) { ++ timeout = msecs_to_jiffies(data->word); ++ i2c_mux_hold(muxc, timeout); ++ } else if (hold_msg == I2C_HOLD_MSG_NONE) { ++ mutex_lock(&muxc->hold_lock); ++ } + ret = muxc->select(muxc, priv->chan_id); + if (ret >= 0) + ret = __i2c_smbus_xfer(parent, addr, flags, + read_write, command, size, data); +- if (muxc->deselect) +- muxc->deselect(muxc, priv->chan_id); ++ if (hold_msg != I2C_HOLD_MSG_SET) { ++ if (muxc->deselect) ++ muxc->deselect(muxc, priv->chan_id); ++ if (hold_msg == I2C_HOLD_MSG_RESET) ++ i2c_mux_unhold(muxc); ++ else ++ mutex_unlock(&muxc->hold_lock); ++ } + + return ret; + } +@@ -104,16 +175,33 @@ static int i2c_mux_smbus_xfer(struct i2c_adapter *adap, + struct i2c_mux_priv *priv = adap->algo_data; + struct i2c_mux_core *muxc = priv->muxc; + struct i2c_adapter *parent = muxc->parent; ++ enum i2c_hold_msg_type hold_msg; ++ unsigned long timeout; + int ret; + + /* Select the right mux port and perform the transfer. */ + ++ hold_msg = i2c_check_hold_msg(flags, ++ size == I2C_SMBUS_WORD_DATA ? 2 : 0, ++ &data->word); ++ if (hold_msg == I2C_HOLD_MSG_SET) { ++ timeout = msecs_to_jiffies(data->word); ++ i2c_mux_hold(muxc, timeout); ++ } else if (hold_msg == I2C_HOLD_MSG_NONE) { ++ mutex_lock(&muxc->hold_lock); ++ } + ret = muxc->select(muxc, priv->chan_id); + if (ret >= 0) + ret = i2c_smbus_xfer(parent, addr, flags, + read_write, command, size, data); +- if (muxc->deselect) +- muxc->deselect(muxc, priv->chan_id); ++ if (hold_msg != I2C_HOLD_MSG_SET) { ++ if (muxc->deselect) ++ muxc->deselect(muxc, priv->chan_id); ++ if (hold_msg == I2C_HOLD_MSG_RESET) ++ i2c_mux_unhold(muxc); ++ else ++ mutex_unlock(&muxc->hold_lock); ++ } + + return ret; + } +@@ -263,6 +351,9 @@ struct i2c_mux_core *i2c_mux_alloc(struct i2c_adapter *parent, + muxc->deselect = deselect; + muxc->max_adapters = max_adapters; + ++ mutex_init(&muxc->hold_lock); ++ timer_setup(&muxc->hold_timer, i2c_mux_hold_timer_callback, 0); ++ + return muxc; + } + EXPORT_SYMBOL_GPL(i2c_mux_alloc); +@@ -441,6 +532,8 @@ void i2c_mux_del_adapters(struct i2c_mux_core *muxc) + { + char symlink_name[20]; + ++ i2c_mux_unhold(muxc); ++ + while (muxc->num_adapters) { + struct i2c_adapter *adap = muxc->adapter[--muxc->num_adapters]; + struct i2c_mux_priv *priv = adap->algo_data; +diff --git a/include/linux/i2c-mux.h b/include/linux/i2c-mux.h +index c5a977320f82..47f8763d6ed2 100644 +--- a/include/linux/i2c-mux.h ++++ b/include/linux/i2c-mux.h +@@ -27,6 +27,9 @@ struct i2c_mux_core { + int (*select)(struct i2c_mux_core *, u32 chan_id); + int (*deselect)(struct i2c_mux_core *, u32 chan_id); + ++ struct mutex hold_lock; /* mutex for channel holding */ ++ struct timer_list hold_timer; ++ + int num_adapters; + int max_adapters; + struct i2c_adapter *adapter[0]; +diff --git a/include/linux/i2c.h b/include/linux/i2c.h +index 1361637c369d..b4055d133338 100644 +--- a/include/linux/i2c.h ++++ b/include/linux/i2c.h +@@ -711,6 +711,13 @@ struct i2c_adapter { + const struct i2c_adapter_quirks *quirks; + + struct irq_domain *host_notify_domain; ++ ++ /* ++ * These will be used by root adpaters only. For muxes, each mux core ++ * has these individually. ++ */ ++ struct mutex hold_lock; /* mutex for bus holding */ ++ struct timer_list hold_timer; + }; + #define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev) + +@@ -1005,4 +1012,22 @@ static inline struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle ha + } + #endif /* CONFIG_ACPI */ + ++enum i2c_hold_msg_type { ++ I2C_HOLD_MSG_NONE, ++ I2C_HOLD_MSG_SET, ++ I2C_HOLD_MSG_RESET ++}; ++ ++static inline enum i2c_hold_msg_type i2c_check_hold_msg(u16 flags, u16 len, u16 *buf) ++{ ++ if (flags & I2C_M_HOLD && len == sizeof(u16)) { ++ if (*buf) ++ return I2C_HOLD_MSG_SET; ++ ++ return I2C_HOLD_MSG_RESET; ++ } ++ ++ return I2C_HOLD_MSG_NONE; ++} ++ + #endif /* _LINUX_I2C_H */ +diff --git a/include/uapi/linux/i2c.h b/include/uapi/linux/i2c.h +index f71a1751cacf..a1db9b17ed36 100644 +--- a/include/uapi/linux/i2c.h ++++ b/include/uapi/linux/i2c.h +@@ -72,6 +72,7 @@ struct i2c_msg { + #define I2C_M_RD 0x0001 /* read data, from slave to master */ + /* I2C_M_RD is guaranteed to be 0x0001! */ + #define I2C_M_TEN 0x0010 /* this is a ten bit chip address */ ++#define I2C_M_HOLD 0x0100 /* for holding a mux path */ + #define I2C_M_DMA_SAFE 0x0200 /* the buffer of this message is DMA safe */ + /* makes only sense in kernelspace */ + /* userspace buffers are copied anyway */ +-- +2.7.4 + |