The PNV I2C Controller was clearing the status register
after a reset without repopulating the "upper threshold
for I2C ports", "Command Complete" and the SCL/SDA input
level fields.
Fixed this for resets caused by a system reset as well
as from writing to the "Immediate Reset" register.
Fixes: 263b81ee15 ("ppc/pnv: Add an I2C controller model")
Signed-off-by: Glenn Miles <milesg@linux.vnet.ibm.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
The PNV I2C engines for power9 and power10 were being assigned a base
XSCOM address that was off by one I2C engine's address range such
that engine 0 had engine 1's address and so on. The xscom address
assignment was being based on the device tree engine numbering, which
starts at 1. Rather than changing the device tree numbering to start
with 0, the addressing was changed to be based on the existing device
tree numbers minus one.
Fixes: 1ceda19c28 ("ppc/pnv: Connect PNV I2C controller to powernv10)
Signed-off-by: Glenn Miles <milesg@linux.vnet.ibm.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Coverity warns that "i2c_bus_busy(i2c->busses[i]) << i" might overflow
because the expression is evaluated using 32-bit arithmetic and then
used in a context expecting a uint64_t.
While we are at it, introduce a PNV_I2C_MAX_BUSSES constant and check
the number of busses at realize time.
Fixes: Coverity CID 1523918
Cc: Glenn Miles <milesg@linux.vnet.ibm.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Glenn Miles <milesg@linux.vnet.ibm.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
The more recent IBM power processors have an embedded I2C
controller that is accessible by software via the XSCOM
address space.
Each instance of the I2C controller is capable of controlling
multiple I2C buses (one at a time). Prior to beginning a
transaction on an I2C bus, the bus must be selected by writing
the port number associated with the bus into the PORT_NUM
field of the MODE register. Once an I2C bus is selected,
the status of the bus can be determined by reading the
Status and Extended Status registers.
I2C bus transactions can be started by writing a command to
the Command register and reading/writing data from/to the
FIFO register.
Not supported :
. 10 bit I2C addresses
. Multimaster
. Slave
Signed-off-by: Cédric Le Goater <clg@kaod.org>
[milesg: Split wiring to powernv9 into its own commit]
[milesg: Added more detail to commit message]
[milesg: Added SPDX Licensed Identifier to new files]
[milesg: updated copyright dates]
[milesg: Added use of g_autofree]
[milesg: Added NULL check after pnv_i2c_get_bus]
Signed-off-by: Glenn Miles <milesg@linux.vnet.ibm.com>
Acked-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-ID: <20231016222013.3739530-2-milesg@linux.vnet.ibm.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
