lkml.org 
[lkml]   [2019]   [Apr]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 1/3] i3c: fix i2c and i3c scl rate by bus mode
Date
Currently in case of mixed slow bus topologie and all i2c devices
support FM+ speed, the i3c subsystem limite the SCL to FM speed.
Also in case on mixed slow bus mode the max speed for both
i2c or i3c transfers is FM or FM+.

This patch fix the definition of i2c and i3c scl rate based on bus
topologie and LVR[4] if no user input.
In case of mixed slow mode the i3c scl rate is overridden.

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>
---
drivers/i3c/master.c | 39 +++++++++++++++++++++++++--------------
1 file changed, 25 insertions(+), 14 deletions(-)

diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
index 909c2ad..1c4a86a 100644
--- a/drivers/i3c/master.c
+++ b/drivers/i3c/master.c
@@ -564,20 +564,30 @@ 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 i2c_scl_rate)
{
i3cbus->mode = mode;

- if (!i3cbus->scl_rate.i3c)
- i3cbus->scl_rate.i3c = I3C_BUS_TYP_I3C_SCL_RATE;
-
- 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;
+ 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 = i2c_scl_rate;
+ break;
+ case I3C_BUS_MODE_MIXED_SLOW:
+ if (!i3cbus->scl_rate.i2c)
+ i3cbus->scl_rate.i2c = i2c_scl_rate;
+ i3cbus->scl_rate.i3c = i3cbus->scl_rate.i2c;
+ break;
+ default:
+ return -EINVAL;
}
-
/*
* I3C/I2C frequency may have been overridden, check that user-provided
* values are not exceeding max possible frequency.
@@ -1980,9 +1990,6 @@ 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);

@@ -2432,6 +2439,7 @@ 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;
@@ -2481,9 +2489,12 @@ 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
\
 
 \ /
  Last update: 2019-04-15 20:43    [W:0.038 / U:2.508 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site