From: Vitor Soares <Vitor.Soares@synopsys.com>
To: linux-i3c@lists.infradead.org
Cc: Joao.Pinto@synopsys.com, Boris Brezillon <bbrezillon@kernel.org>,
linux-kernel@vger.kernel.org, stable@vger.kernel.org,
Vitor Soares <Vitor.Soares@synopsys.com>
Subject: [PATCH v2 1/3] i3c: fix i2c and i3c scl rate by bus mode
Date: Thu, 6 Jun 2019 16:00:01 +0200 [thread overview]
Message-ID: <47de89f2335930df0ed6903be9afe6de4f46e503.1559821228.git.vitor.soares@synopsys.com> (raw)
In-Reply-To: <cover.1559821227.git.vitor.soares@synopsys.com>
In-Reply-To: <cover.1559821227.git.vitor.soares@synopsys.com>
Currently the I3C framework limits SCL frequency to FM speed when
dealing with a mixed slow bus, even if all I2C devices are FM+ capable.
The core was also not accounting for I3C speed limitations when
operating in mixed slow mode and was erroneously using FM+ speed as the
max I2C speed when operating in mixed fast mode.
Fixes: 3a379bbcea0a ("i3c: Add core I3C infrastructure")
Signed-off-by: Vitor Soares <vitor.soares@synopsys.com>
Cc: Boris Brezillon <bbrezillon@kernel.org>
Cc: <stable@vger.kernel.org>
Cc: <linux-kernel@vger.kernel.org>
---
Changes in v2:
Enhance commit message
Add dev_warn() in case user-defined i2c rate doesn't match LVR constraint
Add dev_warn() in case user-defined i3c rate lower than i2c rate.
drivers/i3c/master.c | 61 +++++++++++++++++++++++++++++++++++++++++-----------
1 file changed, 48 insertions(+), 13 deletions(-)
diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
index 5f4bd52..8cd5824 100644
--- a/drivers/i3c/master.c
+++ b/drivers/i3c/master.c
@@ -91,6 +91,12 @@ void i3c_bus_normaluse_unlock(struct i3c_bus *bus)
up_read(&bus->lock);
}
+static struct i3c_master_controller *
+i3c_bus_to_i3c_master(struct i3c_bus *i3cbus)
+{
+ return container_of(i3cbus, struct i3c_master_controller, bus);
+}
+
static struct i3c_master_controller *dev_to_i3cmaster(struct device *dev)
{
return container_of(dev, struct i3c_master_controller, dev);
@@ -565,20 +571,48 @@ static const struct device_type i3c_masterdev_type = {
.groups = i3c_masterdev_groups,
};
-int i3c_bus_set_mode(struct i3c_bus *i3cbus, enum i3c_bus_mode mode)
+int i3c_bus_set_mode(struct i3c_bus *i3cbus, enum i3c_bus_mode mode,
+ unsigned long max_i2c_scl_rate)
{
- i3cbus->mode = mode;
- if (!i3cbus->scl_rate.i3c)
- i3cbus->scl_rate.i3c = I3C_BUS_TYP_I3C_SCL_RATE;
+ struct i3c_master_controller *master = i3c_bus_to_i3c_master(i3cbus);
- if (!i3cbus->scl_rate.i2c) {
- if (i3cbus->mode == I3C_BUS_MODE_MIXED_SLOW)
- i3cbus->scl_rate.i2c = I3C_BUS_I2C_FM_SCL_RATE;
- else
- i3cbus->scl_rate.i2c = I3C_BUS_I2C_FM_PLUS_SCL_RATE;
+ i3cbus->mode = mode;
+
+ switch (i3cbus->mode) {
+ case I3C_BUS_MODE_PURE:
+ if (!i3cbus->scl_rate.i3c)
+ i3cbus->scl_rate.i3c = I3C_BUS_TYP_I3C_SCL_RATE;
+ break;
+ case I3C_BUS_MODE_MIXED_FAST:
+ if (!i3cbus->scl_rate.i3c)
+ i3cbus->scl_rate.i3c = I3C_BUS_TYP_I3C_SCL_RATE;
+ if (!i3cbus->scl_rate.i2c)
+ i3cbus->scl_rate.i2c = max_i2c_scl_rate;
+ break;
+ case I3C_BUS_MODE_MIXED_SLOW:
+ if (!i3cbus->scl_rate.i2c)
+ i3cbus->scl_rate.i2c = max_i2c_scl_rate;
+ if (!i3cbus->scl_rate.i3c ||
+ i3cbus->scl_rate.i3c > i3cbus->scl_rate.i2c)
+ i3cbus->scl_rate.i3c = i3cbus->scl_rate.i2c;
+ break;
+ default:
+ return -EINVAL;
}
+ if (i3cbus->scl_rate.i3c < i3cbus->scl_rate.i2c)
+ dev_warn(&master->dev,
+ "i3c-scl-hz=%ld lower than i2c-scl-hz=%ld\n",
+ i3cbus->scl_rate.i3c, i3cbus->scl_rate.i2c);
+
+ if (i3cbus->scl_rate.i2c != I3C_BUS_I2C_FM_SCL_RATE &&
+ i3cbus->scl_rate.i2c != I3C_BUS_I2C_FM_PLUS_SCL_RATE &&
+ i3cbus->mode != I3C_BUS_MODE_PURE)
+ dev_warn(&master->dev,
+ "i2c-scl-hz=%ld not defined according MIPI I3C spec\n"
+ , i3cbus->scl_rate.i2c);
+
/*
* I3C/I2C frequency may have been overridden, check that user-provided
* values are not exceeding max possible frequency.
@@ -1966,9 +2000,6 @@ of_i3c_master_add_i2c_boardinfo(struct i3c_master_controller *master,
/* LVR is encoded in reg[2]. */
boardinfo->lvr = reg[2];
- if (boardinfo->lvr & I3C_LVR_I2C_FM_MODE)
- master->bus.scl_rate.i2c = I3C_BUS_I2C_FM_SCL_RATE;
-
list_add_tail(&boardinfo->node, &master->boardinfo.i2c);
of_node_get(node);
@@ -2417,6 +2448,7 @@ int i3c_master_register(struct i3c_master_controller *master,
const struct i3c_master_controller_ops *ops,
bool secondary)
{
+ unsigned long i2c_scl_rate = I3C_BUS_I2C_FM_PLUS_SCL_RATE;
struct i3c_bus *i3cbus = i3c_master_get_bus(master);
enum i3c_bus_mode mode = I3C_BUS_MODE_PURE;
struct i2c_dev_boardinfo *i2cbi;
@@ -2466,9 +2498,12 @@ int i3c_master_register(struct i3c_master_controller *master,
ret = -EINVAL;
goto err_put_dev;
}
+
+ if (i2cbi->lvr & I3C_LVR_I2C_FM_MODE)
+ i2c_scl_rate = I3C_BUS_I2C_FM_SCL_RATE;
}
- ret = i3c_bus_set_mode(i3cbus, mode);
+ ret = i3c_bus_set_mode(i3cbus, mode, i2c_scl_rate);
if (ret)
goto err_put_dev;
--
2.7.4
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next prev parent reply other threads:[~2019-06-06 14:00 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-06 14:00 [PATCH v2 0/3] Fix i2c and i3c scl rate according bus mode Vitor Soares
2019-06-06 14:00 ` Vitor Soares [this message]
2019-06-06 14:18 ` [PATCH v2 1/3] i3c: fix i2c and i3c scl rate by " Boris Brezillon
2019-06-06 17:16 ` Vitor Soares
2019-06-06 17:35 ` Boris Brezillon
2019-06-06 18:08 ` Vitor Soares
2019-06-06 19:04 ` Boris Brezillon
2019-06-06 14:00 ` [PATCH v2 2/3] i3c: add mixed limited " Vitor Soares
2019-06-06 14:00 ` [PATCH v2 3/3] i3c: dw: add limited bus mode support Vitor Soares
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