Merge branch 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux

Pull i2c updates from Wolfram Sang:
 "Most notable:

   - introducing the i2c_quirk infrastructure.  Now, flaws of I2C
     controllers can be described and the core will check if the flaws
     collide with the messages to be sent

   - wait_for_completion return type cleanup series

   - new drivers for Digicolor, Netlogic XLP, Ingenic JZ4780

   - updates to the I2C slave framework which include API changes.  Its
     only user was updated, too.  Documentation was finally added

   - changed dynamic bus numbering for the DT case.  This could change
     bus numbers for users.  However, it fixes a collision where dynamic
     and static busses request the same id.

   - driver bugfixes, cleanups"

* 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (52 commits)
  i2c: xlp9xx: Driver for Netlogic XLP9XX/5XX I2C controller
  of: Add vendor prefix 'netlogic'
  i2c: davinci: use ICPFUNC to toggle I2C as gpio for bus recovery
  i2c: davinci: use bus recovery infrastructure
  i2c: change input parameter to i2c_adapter for prepare/unprepare_recovery
  i2c: i2c-mux-gpio: remove error messages for probe deferrals
  i2c: jz4780: Add i2c bus controller driver for Ingenic JZ4780
  i2c: dln2: set the device tree node of the adapter
  i2c: davinci: fixup wait_for_completion_timeout handling
  i2c: mpc: Fix ISR return value
  i2c: slave-eeprom: add more info when to increase the pointer
  i2c: slave: add documentation for i2c-slave-eeprom
  Documentation: i2c: describe the new slave mode
  i2c: slave: rework the slave API
  i2c: add support for the Digicolor I2C controller
  i2c: busses with dynamic ids should start after fixed ids for DT
  of: base: add function to get highest id of an alias stem
  i2c: designware: Suppress error message if platform_get_irq() < 0
  i2c: mpc: assign the correct prescaler from SVR
  i2c: img-scb: fixup of wait_for_completion_timeout return handling
  ...
This commit is contained in:
Linus Torvalds
2015-04-14 18:10:45 -07:00
46 changed files with 2483 additions and 276 deletions
@@ -10,6 +10,9 @@ Required properties:
Recommended properties :
- interrupts : standard interrupt property.
- clock-frequency : desired I2C bus clock frequency in Hz.
- ti,has-pfunc: boolean; if defined, it indicates that SoC supports PFUNC
registers. PFUNC registers allow to switch I2C pins to function as
GPIOs, so they can by toggled manually.
Example (enbw_cmc board):
i2c@1c22000 {
@@ -0,0 +1,25 @@
Conexant Digicolor I2C controller
Required properties:
- compatible: must be "cnxt,cx92755-i2c"
- reg: physical address and length of the device registers
- interrupts: a single interrupt specifier
- clocks: clock for the device
- #address-cells: should be <1>
- #size-cells: should be <0>
Optional properties:
- clock-frequency: the desired I2C bus clock frequency in Hz; in
absence of this property the default value is used (100 kHz).
Example:
i2c: i2c@f0000120 {
compatible = "cnxt,cx92755-i2c";
reg = <0xf0000120 0x10>;
interrupts = <28>;
clocks = <&main_clk>;
clock-frequency = <100000>;
#address-cells = <1>;
#size-cells = <0>;
};
@@ -0,0 +1,35 @@
* Ingenic JZ4780 I2C Bus controller
Required properties:
- compatible: should be "ingenic,jz4780-i2c"
- reg: Should contain the address & size of the I2C controller registers.
- interrupts: Should specify the interrupt provided by parent.
- clocks: Should contain a single clock specifier for the JZ4780 I2C clock.
- clock-frequency: desired I2C bus clock frequency in Hz.
Recommended properties:
- pinctrl-names: should be "default";
- pinctrl-0: phandle to pinctrl function
Optional properties:
- interrupt-parent: Should be the phandle of the interrupt controller that
delivers interrupts to the I2C block.
Example
/ {
i2c4: i2c4@0x10054000 {
compatible = "ingenic,jz4780-i2c";
reg = <0x10054000 0x1000>;
interrupt-parent = <&intc>;
interrupts = <56>;
clocks = <&cgu JZ4780_CLK_SMB4>;
clock-frequency = <100000>;
pinctrl-names = "default";
pinctrl-0 = <&pins_i2c4_data>;
};
};
@@ -0,0 +1,22 @@
Device tree configuration for the I2C controller on the XLP9xx/5xx SoC
Required properties:
- compatible : should be "netlogic,xlp980-i2c"
- reg : bus address start and address range size of device
- interrupts : interrupt number
Optional properties:
- clock-frequency : frequency of bus clock in Hz
Defaults to 100 KHz when the property is not specified
Example:
i2c0: i2c@113100 {
compatible = "netlogic,xlp980-i2c";
#address-cells = <1>;
#size-cells = <0>;
reg = <0 0x113100 0x100>;
clock-frequency = <400000>;
interrupts = <30>;
interrupt-parent = <&pic>;
};
@@ -125,6 +125,7 @@ mxicy Macronix International Co., Ltd.
national National Semiconductor
neonode Neonode Inc.
netgear NETGEAR
netlogic Broadcom Corporation (formerly NetLogic Microsystems)
newhaven Newhaven Display International
nintendo Nintendo
nokia Nokia
+14
View File
@@ -0,0 +1,14 @@
Linux I2C slave eeprom backend
==============================
by Wolfram Sang <wsa@sang-engineering.com> in 2014-15
This is a proof-of-concept backend which acts like an EEPROM on the connected
I2C bus. The memory contents can be modified from userspace via this file
located in sysfs:
/sys/bus/i2c/devices/<device-direcory>/slave-eeprom
As of 2015, Linux doesn't support poll on binary sysfs files, so there is no
notfication when another master changed the content.
+179
View File
@@ -0,0 +1,179 @@
Linux I2C slave interface description
=====================================
by Wolfram Sang <wsa@sang-engineering.com> in 2014-15
Linux can also be an I2C slave in case I2C controllers have slave support.
Besides this HW requirement, one also needs a software backend providing the
actual functionality. An example for this is the slave-eeprom driver, which
acts as a dual memory driver. While another I2C master on the bus can access it
like a regular EEPROM, the Linux I2C slave can access the content via sysfs and
retrieve/provide information as needed. The software backend driver and the I2C
bus driver communicate via events. Here is a small graph visualizing the data
flow and the means by which data is transported. The dotted line marks only one
example. The backend could also use e.g. a character device, be in-kernel
only, or something completely different:
e.g. sysfs I2C slave events I/O registers
+-----------+ v +---------+ v +--------+ v +------------+
| Userspace +........+ Backend +-----------+ Driver +-----+ Controller |
+-----------+ +---------+ +--------+ +------------+
| |
----------------------------------------------------------------+-- I2C
--------------------------------------------------------------+---- Bus
Note: Technically, there is also the I2C core between the backend and the
driver. However, at this time of writing, the layer is transparent.
User manual
===========
I2C slave backends behave like standard I2C clients. So, you can instantiate
them like described in the document 'instantiating-devices'. A quick example
for instantiating the slave-eeprom driver from userspace:
# echo 0-0064 > /sys/bus/i2c/drivers/i2c-slave-eeprom/bind
Each backend should come with separate documentation to describe its specific
behaviour and setup.
Developer manual
================
I2C slave events
----------------
The bus driver sends an event to the backend using the following function:
ret = i2c_slave_event(client, event, &val)
'client' describes the i2c slave device. 'event' is one of the special event
types described hereafter. 'val' holds an u8 value for the data byte to be
read/written and is thus bidirectional. The pointer to val must always be
provided even if val is not used for an event, i.e. don't use NULL here. 'ret'
is the return value from the backend. Mandatory events must be provided by the
bus drivers and must be checked for by backend drivers.
Event types:
* I2C_SLAVE_WRITE_REQUESTED (mandatory)
'val': unused
'ret': always 0
Another I2C master wants to write data to us. This event should be sent once
our own address and the write bit was detected. The data did not arrive yet, so
there is nothing to process or return. Wakeup or initialization probably needs
to be done, though.
* I2C_SLAVE_READ_REQUESTED (mandatory)
'val': backend returns first byte to be sent
'ret': always 0
Another I2C master wants to read data from us. This event should be sent once
our own address and the read bit was detected. After returning, the bus driver
should transmit the first byte.
* I2C_SLAVE_WRITE_RECEIVED (mandatory)
'val': bus driver delivers received byte
'ret': 0 if the byte should be acked, some errno if the byte should be nacked
Another I2C master has sent a byte to us which needs to be set in 'val'. If 'ret'
is zero, the bus driver should ack this byte. If 'ret' is an errno, then the byte
should be nacked.
* I2C_SLAVE_READ_PROCESSED (mandatory)
'val': backend returns next byte to be sent
'ret': always 0
The bus driver requests the next byte to be sent to another I2C master in
'val'. Important: This does not mean that the previous byte has been acked, it
only means that the previous byte is shifted out to the bus! To ensure seamless
transmission, most hardware requests the next byte when the previous one is
still shifted out. If the master sends NACK and stops reading after the byte
currently shifted out, this byte requested here is never used. It very likely
needs to be sent again on the next I2C_SLAVE_READ_REQUEST, depending a bit on
your backend, though.
* I2C_SLAVE_STOP (mandatory)
'val': unused
'ret': always 0
A stop condition was received. This can happen anytime and the backend should
reset its state machine for I2C transfers to be able to receive new requests.
Software backends
-----------------
If you want to write a software backend:
* use a standard i2c_driver and its matching mechanisms
* write the slave_callback which handles the above slave events
(best using a state machine)
* register this callback via i2c_slave_register()
Check the i2c-slave-eeprom driver as an example.
Bus driver support
------------------
If you want to add slave support to the bus driver:
* implement calls to register/unregister the slave and add those to the
struct i2c_algorithm. When registering, you probably need to set the i2c
slave address and enable slave specific interrupts. If you use runtime pm, you
should use pm_runtime_forbid() because your device usually needs to be powered
on always to be able to detect its slave address. When unregistering, do the
inverse of the above.
* Catch the slave interrupts and send appropriate i2c_slave_events to the backend.
Check the i2c-rcar driver as an example.
About ACK/NACK
--------------
It is good behaviour to always ACK the address phase, so the master knows if a
device is basically present or if it mysteriously disappeared. Using NACK to
state being busy is troublesome. SMBus demands to always ACK the address phase,
while the I2C specification is more loose on that. Most I2C controllers also
automatically ACK when detecting their slave addresses, so there is no option
to NACK them. For those reasons, this API does not support NACK in the address
phase.
Currently, there is no slave event to report if the master did ACK or NACK a
byte when it reads from us. We could make this an optional event if the need
arises. However, cases should be extremely rare because the master is expected
to send STOP after that and we have an event for that. Also, keep in mind not
all I2C controllers have the possibility to report that event.
About buffers
-------------
During development of this API, the question of using buffers instead of just
bytes came up. Such an extension might be possible, usefulness is unclear at
this time of writing. Some points to keep in mind when using buffers:
* Buffers should be opt-in and slave drivers will always have to support
byte-based transactions as the ultimate fallback because this is how the
majority of HW works.
* For backends simulating hardware registers, buffers are not helpful because
on writes an action should be immediately triggered. For reads, the data in
the buffer might get stale.
* A master can send STOP at any time. For partially transferred buffers, this
means additional code to handle this exception. Such code tends to be
error-prone.
-4
View File
@@ -41,7 +41,3 @@ integrated than Algorithm and Adapter.
For a given configuration, you will need a driver for your I2C bus, and
drivers for your I2C devices (usually one driver for each device).
At this time, Linux only operates I2C (or SMBus) in master mode; you can't
use these APIs to make a Linux system behave as a slave/device, either to
speak a custom protocol or to emulate some other device.
+28
View File
@@ -485,6 +485,15 @@ config I2C_DESIGNWARE_BAYTRAIL
the platform firmware controlling it. You should say Y if running on
a BayTrail system using the AXP288.
config I2C_DIGICOLOR
tristate "Conexant Digicolor I2C driver"
depends on ARCH_DIGICOLOR
help
Support for Conexant Digicolor SoCs (CX92755) I2C controller driver.
This driver can also be built as a module. If so, the module
will be called i2c-digicolor.
config I2C_EFM32
tristate "EFM32 I2C controller"
depends on ARCH_EFM32 || COMPILE_TEST
@@ -574,6 +583,15 @@ config I2C_IOP3XX
This driver can also be built as a module. If so, the module
will be called i2c-iop3xx.
config I2C_JZ4780
tristate "JZ4780 I2C controller interface support"
depends on MACH_JZ4780 || COMPILE_TEST
help
If you say yes to this option, support will be included for the
Ingenic JZ4780 I2C controller.
If you don't know what to do here, say N.
config I2C_KEMPLD
tristate "Kontron COM I2C Controller"
depends on MFD_KEMPLD
@@ -898,6 +916,16 @@ config I2C_XLR
This driver can also be built as a module. If so, the module
will be called i2c-xlr.
config I2C_XLP9XX
tristate "XLP9XX I2C support"
depends on CPU_XLP || COMPILE_TEST
help
This driver enables support for the on-chip I2C interface of
the Broadcom XLP9xx/XLP5xx MIPS processors.
This driver can also be built as a module. If so, the module will
be called i2c-xlp9xx.
config I2C_RCAR
tristate "Renesas R-Car I2C Controller"
depends on ARCH_SHMOBILE || COMPILE_TEST
+3
View File
@@ -45,6 +45,7 @@ i2c-designware-platform-objs := i2c-designware-platdrv.o
i2c-designware-platform-$(CONFIG_I2C_DESIGNWARE_BAYTRAIL) += i2c-designware-baytrail.o
obj-$(CONFIG_I2C_DESIGNWARE_PCI) += i2c-designware-pci.o
i2c-designware-pci-objs := i2c-designware-pcidrv.o
obj-$(CONFIG_I2C_DIGICOLOR) += i2c-digicolor.o
obj-$(CONFIG_I2C_EFM32) += i2c-efm32.o
obj-$(CONFIG_I2C_EG20T) += i2c-eg20t.o
obj-$(CONFIG_I2C_EXYNOS5) += i2c-exynos5.o
@@ -55,6 +56,7 @@ obj-$(CONFIG_I2C_IBM_IIC) += i2c-ibm_iic.o
obj-$(CONFIG_I2C_IMG) += i2c-img-scb.o
obj-$(CONFIG_I2C_IMX) += i2c-imx.o
obj-$(CONFIG_I2C_IOP3XX) += i2c-iop3xx.o
obj-$(CONFIG_I2C_JZ4780) += i2c-jz4780.o
obj-$(CONFIG_I2C_KEMPLD) += i2c-kempld.o
obj-$(CONFIG_I2C_MESON) += i2c-meson.o
obj-$(CONFIG_I2C_MPC) += i2c-mpc.o
@@ -87,6 +89,7 @@ obj-$(CONFIG_I2C_WMT) += i2c-wmt.o
obj-$(CONFIG_I2C_OCTEON) += i2c-octeon.o
obj-$(CONFIG_I2C_XILINX) += i2c-xiic.o
obj-$(CONFIG_I2C_XLR) += i2c-xlr.o
obj-$(CONFIG_I2C_XLP9XX) += i2c-xlp9xx.o
obj-$(CONFIG_I2C_RCAR) += i2c-rcar.o
# External I2C/SMBus adapter drivers
+15 -24
View File
@@ -381,6 +381,7 @@ static irqreturn_t atmel_twi_interrupt(int irq, void *dev_id)
static int at91_do_twi_transfer(struct at91_twi_dev *dev)
{
int ret;
unsigned long time_left;
bool has_unre_flag = dev->pdata->has_unre_flag;
dev_dbg(dev->dev, "transfer: %s %d bytes.\n",
@@ -436,9 +437,9 @@ static int at91_do_twi_transfer(struct at91_twi_dev *dev)
}
}
ret = wait_for_completion_timeout(&dev->cmd_complete,
dev->adapter.timeout);
if (ret == 0) {
time_left = wait_for_completion_timeout(&dev->cmd_complete,
dev->adapter.timeout);
if (time_left == 0) {
dev_err(dev->dev, "controller timed out\n");
at91_init_twi_bus(dev);
ret = -ETIMEDOUT;
@@ -487,30 +488,10 @@ static int at91_twi_xfer(struct i2c_adapter *adap, struct i2c_msg *msg, int num)
if (ret < 0)
goto out;
/*
* The hardware can handle at most two messages concatenated by a
* repeated start via it's internal address feature.
*/
if (num > 2) {
dev_err(dev->dev,
"cannot handle more than two concatenated messages.\n");
ret = 0;
goto out;
} else if (num == 2) {
if (num == 2) {
int internal_address = 0;
int i;
if (msg->flags & I2C_M_RD) {
dev_err(dev->dev, "first transfer must be write.\n");
ret = -EINVAL;
goto out;
}
if (msg->len > 3) {
dev_err(dev->dev, "first message size must be <= 3.\n");
ret = -EINVAL;
goto out;
}
/* 1st msg is put into the internal address, start with 2nd */
m_start = &msg[1];
for (i = 0; i < msg->len; ++i) {
@@ -540,6 +521,15 @@ out:
return ret;
}
/*
* The hardware can handle at most two messages concatenated by a
* repeated start via it's internal address feature.
*/
static struct i2c_adapter_quirks at91_twi_quirks = {
.flags = I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | I2C_AQ_COMB_SAME_ADDR,
.max_comb_1st_msg_len = 3,
};
static u32 at91_twi_func(struct i2c_adapter *adapter)
{
return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL
@@ -777,6 +767,7 @@ static int at91_twi_probe(struct platform_device *pdev)
dev->adapter.owner = THIS_MODULE;
dev->adapter.class = I2C_CLASS_DEPRECATED;
dev->adapter.algo = &at91_twi_algorithm;
dev->adapter.quirks = &at91_twi_quirks;
dev->adapter.dev.parent = dev->dev;
dev->adapter.nr = pdev->id;
dev->adapter.timeout = AT91_I2C_TIMEOUT;
+14 -13
View File
@@ -334,12 +334,7 @@ static int axxia_i2c_xfer_msg(struct axxia_i2c_dev *idev, struct i2c_msg *msg)
u32 int_mask = MST_STATUS_ERR | MST_STATUS_SNS;
u32 rx_xfer, tx_xfer;
u32 addr_1, addr_2;
int ret;
if (msg->len > 255) {
dev_warn(idev->dev, "unsupported length %u\n", msg->len);
return -EINVAL;
}
unsigned long time_left;
idev->msg = msg;
idev->msg_xfrd = 0;
@@ -388,15 +383,15 @@ static int axxia_i2c_xfer_msg(struct axxia_i2c_dev *idev, struct i2c_msg *msg)
i2c_int_enable(idev, int_mask);
ret = wait_for_completion_timeout(&idev->msg_complete,
I2C_XFER_TIMEOUT);
time_left = wait_for_completion_timeout(&idev->msg_complete,
I2C_XFER_TIMEOUT);
i2c_int_disable(idev, int_mask);
if (readl(idev->base + MST_COMMAND) & CMD_BUSY)
dev_warn(idev->dev, "busy after xfer\n");
if (ret == 0)
if (time_left == 0)
idev->msg_err = -ETIMEDOUT;
if (unlikely(idev->msg_err) && idev->msg_err != -ENXIO)
@@ -408,17 +403,17 @@ static int axxia_i2c_xfer_msg(struct axxia_i2c_dev *idev, struct i2c_msg *msg)
static int axxia_i2c_stop(struct axxia_i2c_dev *idev)
{
u32 int_mask = MST_STATUS_ERR | MST_STATUS_SCC;
int ret;
unsigned long time_left;
reinit_completion(&idev->msg_complete);
/* Issue stop */
writel(0xb, idev->base + MST_COMMAND);
i2c_int_enable(idev, int_mask);
ret = wait_for_completion_timeout(&idev->msg_complete,
I2C_STOP_TIMEOUT);
time_left = wait_for_completion_timeout(&idev->msg_complete,
I2C_STOP_TIMEOUT);
i2c_int_disable(idev, int_mask);
if (ret == 0)
if (time_left == 0)
return -ETIMEDOUT;
if (readl(idev->base + MST_COMMAND) & CMD_BUSY)
@@ -454,6 +449,11 @@ static const struct i2c_algorithm axxia_i2c_algo = {
.functionality = axxia_i2c_func,
};
static struct i2c_adapter_quirks axxia_i2c_quirks = {
.max_read_len = 255,
.max_write_len = 255,
};
static int axxia_i2c_probe(struct platform_device *pdev)
{
struct device_node *np = pdev->dev.of_node;
@@ -511,6 +511,7 @@ static int axxia_i2c_probe(struct platform_device *pdev)
strlcpy(idev->adapter.name, pdev->name, sizeof(idev->adapter.name));
idev->adapter.owner = THIS_MODULE;
idev->adapter.algo = &axxia_i2c_algo;
idev->adapter.quirks = &axxia_i2c_quirks;
idev->adapter.dev.parent = &pdev->dev;
idev->adapter.dev.of_node = pdev->dev.of_node;
+7 -8
View File
@@ -160,14 +160,6 @@ static int bcm_iproc_i2c_xfer_single_msg(struct bcm_iproc_i2c_dev *iproc_i2c,
u32 val;
unsigned long time_left = msecs_to_jiffies(I2C_TIMEOUT_MESC);
/* need to reserve one byte in the FIFO for the slave address */
if (msg->len > M_TX_RX_FIFO_SIZE - 1) {
dev_err(iproc_i2c->device,
"only support data length up to %u bytes\n",
M_TX_RX_FIFO_SIZE - 1);
return -EOPNOTSUPP;
}
/* check if bus is busy */
if (!!(readl(iproc_i2c->base + M_CMD_OFFSET) &
BIT(M_CMD_START_BUSY_SHIFT))) {
@@ -287,6 +279,12 @@ static const struct i2c_algorithm bcm_iproc_algo = {
.functionality = bcm_iproc_i2c_functionality,
};
static struct i2c_adapter_quirks bcm_iproc_i2c_quirks = {
/* need to reserve one byte in the FIFO for the slave address */
.max_read_len = M_TX_RX_FIFO_SIZE - 1,
.max_write_len = M_TX_RX_FIFO_SIZE - 1,
};
static int bcm_iproc_i2c_cfg_speed(struct bcm_iproc_i2c_dev *iproc_i2c)
{
unsigned int bus_speed;
@@ -413,6 +411,7 @@ static int bcm_iproc_i2c_probe(struct platform_device *pdev)
i2c_set_adapdata(adap, iproc_i2c);
strlcpy(adap->name, "Broadcom iProc I2C adapter", sizeof(adap->name));
adap->algo = &bcm_iproc_algo;
adap->quirks = &bcm_iproc_i2c_quirks;
adap->dev.parent = &pdev->dev;
adap->dev.of_node = pdev->dev.of_node;
+1 -1
View File
@@ -147,7 +147,7 @@ static int bcm2835_i2c_xfer_msg(struct bcm2835_i2c_dev *i2c_dev,
struct i2c_msg *msg)
{
u32 c;
int time_left;
unsigned long time_left;
i2c_dev->msg_buf = msg->buf;
i2c_dev->msg_buf_remaining = msg->len;
+3 -3
View File
@@ -475,7 +475,7 @@ static void cdns_i2c_master_reset(struct i2c_adapter *adap)
static int cdns_i2c_process_msg(struct cdns_i2c *id, struct i2c_msg *msg,
struct i2c_adapter *adap)
{
int ret;
unsigned long time_left;
u32 reg;
id->p_msg = msg;
@@ -501,8 +501,8 @@ static int cdns_i2c_process_msg(struct cdns_i2c *id, struct i2c_msg *msg,
cdns_i2c_msend(id);
/* Wait for the signal of completion */
ret = wait_for_completion_timeout(&id->xfer_done, adap->timeout);
if (!ret) {
time_left = wait_for_completion_timeout(&id->xfer_done, adap->timeout);
if (time_left == 0) {
cdns_i2c_master_reset(adap);
dev_err(id->adap.dev.parent,
"timeout waiting on completion\n");
+9 -11
View File
@@ -308,22 +308,12 @@ static int cpm_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
struct i2c_reg __iomem *i2c_reg = cpm->i2c_reg;
struct i2c_ram __iomem *i2c_ram = cpm->i2c_ram;
struct i2c_msg *pmsg;
int ret, i;
int ret;
int tptr;
int rptr;
cbd_t __iomem *tbdf;
cbd_t __iomem *rbdf;
if (num > CPM_MAXBD)
return -EINVAL;
/* Check if we have any oversized READ requests */
for (i = 0; i < num; i++) {
pmsg = &msgs[i];
if (pmsg->len >= CPM_MAX_READ)
return -EINVAL;
}
/* Reset to use first buffer */
out_be16(&i2c_ram->rbptr, in_be16(&i2c_ram->rbase));
out_be16(&i2c_ram->tbptr, in_be16(&i2c_ram->tbase));
@@ -424,10 +414,18 @@ static const struct i2c_algorithm cpm_i2c_algo = {
.functionality = cpm_i2c_func,
};
/* CPM_MAX_READ is also limiting writes according to the code! */
static struct i2c_adapter_quirks cpm_i2c_quirks = {
.max_num_msgs = CPM_MAXBD,
.max_read_len = CPM_MAX_READ,
.max_write_len = CPM_MAX_READ,
};
static const struct i2c_adapter cpm_ops = {
.owner = THIS_MODULE,
.name = "i2c-cpm",
.algo = &cpm_i2c_algo,
.quirks = &cpm_i2c_quirks,
};
static int cpm_i2c_setup(struct cpm_i2c *cpm)
+143 -51
View File
@@ -60,6 +60,12 @@
#define DAVINCI_I2C_IVR_REG 0x28
#define DAVINCI_I2C_EMDR_REG 0x2c
#define DAVINCI_I2C_PSC_REG 0x30
#define DAVINCI_I2C_FUNC_REG 0x48
#define DAVINCI_I2C_DIR_REG 0x4c
#define DAVINCI_I2C_DIN_REG 0x50
#define DAVINCI_I2C_DOUT_REG 0x54
#define DAVINCI_I2C_DSET_REG 0x58
#define DAVINCI_I2C_DCLR_REG 0x5c
#define DAVINCI_I2C_IVR_AAS 0x07
#define DAVINCI_I2C_IVR_SCD 0x06
@@ -93,6 +99,29 @@
#define DAVINCI_I2C_IMR_NACK BIT(1)
#define DAVINCI_I2C_IMR_AL BIT(0)
/* set SDA and SCL as GPIO */
#define DAVINCI_I2C_FUNC_PFUNC0 BIT(0)
/* set SCL as output when used as GPIO*/
#define DAVINCI_I2C_DIR_PDIR0 BIT(0)
/* set SDA as output when used as GPIO*/
#define DAVINCI_I2C_DIR_PDIR1 BIT(1)
/* read SCL GPIO level */
#define DAVINCI_I2C_DIN_PDIN0 BIT(0)
/* read SDA GPIO level */
#define DAVINCI_I2C_DIN_PDIN1 BIT(1)
/*set the SCL GPIO high */
#define DAVINCI_I2C_DSET_PDSET0 BIT(0)
/*set the SDA GPIO high */
#define DAVINCI_I2C_DSET_PDSET1 BIT(1)
/* set the SCL GPIO low */
#define DAVINCI_I2C_DCLR_PDCLR0 BIT(0)
/* set the SDA GPIO low */
#define DAVINCI_I2C_DCLR_PDCLR1 BIT(1)
struct davinci_i2c_dev {
struct device *dev;
void __iomem *base;
@@ -129,43 +158,6 @@ static inline u16 davinci_i2c_read_reg(struct davinci_i2c_dev *i2c_dev, int reg)
return readw_relaxed(i2c_dev->base + reg);
}
/* Generate a pulse on the i2c clock pin. */
static void davinci_i2c_clock_pulse(unsigned int scl_pin)
{
u16 i;
if (scl_pin) {
/* Send high and low on the SCL line */
for (i = 0; i < 9; i++) {
gpio_set_value(scl_pin, 0);
udelay(20);
gpio_set_value(scl_pin, 1);
udelay(20);
}
}
}
/* This routine does i2c bus recovery as specified in the
* i2c protocol Rev. 03 section 3.16 titled "Bus clear"
*/
static void davinci_i2c_recover_bus(struct davinci_i2c_dev *dev)
{
u32 flag = 0;
struct davinci_i2c_platform_data *pdata = dev->pdata;
dev_err(dev->dev, "initiating i2c bus recovery\n");
/* Send NACK to the slave */
flag = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG);
flag |= DAVINCI_I2C_MDR_NACK;
/* write the data into mode register */
davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, flag);
davinci_i2c_clock_pulse(pdata->scl_pin);
/* Send STOP */
flag = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG);
flag |= DAVINCI_I2C_MDR_STP;
davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, flag);
}
static inline void davinci_i2c_reset_ctrl(struct davinci_i2c_dev *i2c_dev,
int val)
{
@@ -262,6 +254,99 @@ static int i2c_davinci_init(struct davinci_i2c_dev *dev)
return 0;
}
/*
* This routine does i2c bus recovery by using i2c_generic_gpio_recovery
* which is provided by I2C Bus recovery infrastructure.
*/
static void davinci_i2c_prepare_recovery(struct i2c_adapter *adap)
{
struct davinci_i2c_dev *dev = i2c_get_adapdata(adap);
/* Disable interrupts */
davinci_i2c_write_reg(dev, DAVINCI_I2C_IMR_REG, 0);
/* put I2C into reset */
davinci_i2c_reset_ctrl(dev, 0);
}
static void davinci_i2c_unprepare_recovery(struct i2c_adapter *adap)
{
struct davinci_i2c_dev *dev = i2c_get_adapdata(adap);
i2c_davinci_init(dev);
}
static struct i2c_bus_recovery_info davinci_i2c_gpio_recovery_info = {
.recover_bus = i2c_generic_gpio_recovery,
.prepare_recovery = davinci_i2c_prepare_recovery,
.unprepare_recovery = davinci_i2c_unprepare_recovery,
};
static void davinci_i2c_set_scl(struct i2c_adapter *adap, int val)
{
struct davinci_i2c_dev *dev = i2c_get_adapdata(adap);
if (val)
davinci_i2c_write_reg(dev, DAVINCI_I2C_DSET_REG,
DAVINCI_I2C_DSET_PDSET0);
else
davinci_i2c_write_reg(dev, DAVINCI_I2C_DCLR_REG,
DAVINCI_I2C_DCLR_PDCLR0);
}
static int davinci_i2c_get_scl(struct i2c_adapter *adap)
{
struct davinci_i2c_dev *dev = i2c_get_adapdata(adap);
int val;
/* read the state of SCL */
val = davinci_i2c_read_reg(dev, DAVINCI_I2C_DIN_REG);
return val & DAVINCI_I2C_DIN_PDIN0;
}
static int davinci_i2c_get_sda(struct i2c_adapter *adap)
{
struct davinci_i2c_dev *dev = i2c_get_adapdata(adap);
int val;
/* read the state of SDA */
val = davinci_i2c_read_reg(dev, DAVINCI_I2C_DIN_REG);
return val & DAVINCI_I2C_DIN_PDIN1;
}
static void davinci_i2c_scl_prepare_recovery(struct i2c_adapter *adap)
{
struct davinci_i2c_dev *dev = i2c_get_adapdata(adap);
davinci_i2c_prepare_recovery(adap);
/* SCL output, SDA input */
davinci_i2c_write_reg(dev, DAVINCI_I2C_DIR_REG, DAVINCI_I2C_DIR_PDIR0);
/* change to GPIO mode */
davinci_i2c_write_reg(dev, DAVINCI_I2C_FUNC_REG,
DAVINCI_I2C_FUNC_PFUNC0);
}
static void davinci_i2c_scl_unprepare_recovery(struct i2c_adapter *adap)
{
struct davinci_i2c_dev *dev = i2c_get_adapdata(adap);
/* change back to I2C mode */
davinci_i2c_write_reg(dev, DAVINCI_I2C_FUNC_REG, 0);
davinci_i2c_unprepare_recovery(adap);
}
static struct i2c_bus_recovery_info davinci_i2c_scl_recovery_info = {
.recover_bus = i2c_generic_scl_recovery,
.set_scl = davinci_i2c_set_scl,
.get_scl = davinci_i2c_get_scl,
.get_sda = davinci_i2c_get_sda,
.prepare_recovery = davinci_i2c_scl_prepare_recovery,
.unprepare_recovery = davinci_i2c_scl_unprepare_recovery,
};
/*
* Waiting for bus not busy
*/
@@ -282,8 +367,7 @@ static int i2c_davinci_wait_bus_not_busy(struct davinci_i2c_dev *dev,
return -ETIMEDOUT;
} else {
to_cnt = 0;
davinci_i2c_recover_bus(dev);
i2c_davinci_init(dev);
i2c_recover_bus(&dev->adapter);
}
}
if (allow_sleep)
@@ -304,7 +388,7 @@ i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop)
struct davinci_i2c_platform_data *pdata = dev->pdata;
u32 flag;
u16 w;
int r;
unsigned long time_left;
/* Introduce a delay, required for some boards (e.g Davinci EVM) */
if (pdata->bus_delay)
@@ -368,11 +452,11 @@ i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop)
flag |= DAVINCI_I2C_MDR_STP;
davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, flag);
r = wait_for_completion_timeout(&dev->cmd_complete, dev->adapter.timeout);
if (r == 0) {
time_left = wait_for_completion_timeout(&dev->cmd_complete,
dev->adapter.timeout);
if (!time_left) {
dev_err(dev->dev, "controller timed out\n");
davinci_i2c_recover_bus(dev);
i2c_davinci_init(dev);
i2c_recover_bus(adap);
dev->buf_len = 0;
return -ETIMEDOUT;
}
@@ -380,17 +464,13 @@ i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop)
/* This should be 0 if all bytes were transferred
* or dev->cmd_err denotes an error.
*/
if (r >= 0) {
dev_err(dev->dev, "abnormal termination buf_len=%i\n",
dev->buf_len);
r = -EREMOTEIO;
}
dev_err(dev->dev, "abnormal termination buf_len=%i\n",
dev->buf_len);
dev->terminate = 1;
wmb();
dev->buf_len = 0;
return -EREMOTEIO;
}
if (r < 0)
return r;
/* no error */
if (likely(!dev->cmd_err))
@@ -674,6 +754,10 @@ static int davinci_i2c_probe(struct platform_device *pdev)
if (!of_property_read_u32(pdev->dev.of_node, "clock-frequency",
&prop))
dev->pdata->bus_freq = prop / 1000;
dev->pdata->has_pfunc =
of_property_read_bool(pdev->dev.of_node,
"ti,has-pfunc");
} else if (!dev->pdata) {
dev->pdata = &davinci_i2c_platform_data_default;
}
@@ -715,6 +799,14 @@ static int davinci_i2c_probe(struct platform_device *pdev)
adap->timeout = DAVINCI_I2C_TIMEOUT;
adap->dev.of_node = pdev->dev.of_node;
if (dev->pdata->has_pfunc)
adap->bus_recovery_info = &davinci_i2c_scl_recovery_info;
else if (dev->pdata->scl_pin) {
adap->bus_recovery_info = &davinci_i2c_gpio_recovery_info;
adap->bus_recovery_info->scl_gpio = dev->pdata->scl_pin;
adap->bus_recovery_info->sda_gpio = dev->pdata->sda_pin;
}
adap->nr = pdev->id;
r = i2c_add_numbered_adapter(adap);
if (r) {
+1 -2
View File
@@ -656,8 +656,7 @@ i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
i2c_dw_xfer_init(dev);
/* wait for tx to complete */
ret = wait_for_completion_timeout(&dev->cmd_complete, HZ);
if (ret == 0) {
if (!wait_for_completion_timeout(&dev->cmd_complete, HZ)) {
dev_err(dev->dev, "controller timed out\n");
/* i2c_dw_init implicitly disables the adapter */
i2c_dw_init(dev);
+2 -4
View File
@@ -143,10 +143,8 @@ static int dw_i2c_probe(struct platform_device *pdev)
u32 clk_freq, ht = 0;
irq = platform_get_irq(pdev, 0);
if (irq < 0) {
dev_err(&pdev->dev, "no irq resource?\n");
return irq; /* -ENXIO */
}
if (irq < 0)
return irq;
dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL);
if (!dev)
+385
View File
@@ -0,0 +1,385 @@
/*
* I2C bus driver for Conexant Digicolor SoCs
*
* Author: Baruch Siach <baruch@tkos.co.il>
*
* Copyright (C) 2015 Paradox Innovation Ltd.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/clk.h>
#include <linux/completion.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#define DEFAULT_FREQ 100000
#define TIMEOUT_MS 100
#define II_CONTROL 0x0
#define II_CONTROL_LOCAL_RESET BIT(0)
#define II_CLOCKTIME 0x1
#define II_COMMAND 0x2
#define II_CMD_START 1
#define II_CMD_RESTART 2
#define II_CMD_SEND_ACK 3
#define II_CMD_GET_ACK 6
#define II_CMD_GET_NOACK 7
#define II_CMD_STOP 10
#define II_COMMAND_GO BIT(7)
#define II_COMMAND_COMPLETION_STATUS(r) (((r) >> 5) & 3)
#define II_CMD_STATUS_NORMAL 0
#define II_CMD_STATUS_ACK_GOOD 1
#define II_CMD_STATUS_ACK_BAD 2
#define II_CMD_STATUS_ABORT 3
#define II_DATA 0x3
#define II_INTFLAG_CLEAR 0x8
#define II_INTENABLE 0xa
struct dc_i2c {
struct i2c_adapter adap;
struct device *dev;
void __iomem *regs;
struct clk *clk;
unsigned int frequency;
struct i2c_msg *msg;
unsigned int msgbuf_ptr;
int last;
spinlock_t lock;
struct completion done;
int state;
int error;
};
enum {
STATE_IDLE,
STATE_START,
STATE_ADDR,
STATE_WRITE,
STATE_READ,
STATE_STOP,
};
static void dc_i2c_cmd(struct dc_i2c *i2c, u8 cmd)
{
writeb_relaxed(cmd | II_COMMAND_GO, i2c->regs + II_COMMAND);
}
static u8 dc_i2c_addr_cmd(struct i2c_msg *msg)
{
u8 addr = (msg->addr & 0x7f) << 1;
if (msg->flags & I2C_M_RD)
addr |= 1;
return addr;
}
static void dc_i2c_data(struct dc_i2c *i2c, u8 data)
{
writeb_relaxed(data, i2c->regs + II_DATA);
}
static void dc_i2c_write_byte(struct dc_i2c *i2c, u8 byte)
{
dc_i2c_data(i2c, byte);
dc_i2c_cmd(i2c, II_CMD_SEND_ACK);
}
static void dc_i2c_write_buf(struct dc_i2c *i2c)
{
dc_i2c_write_byte(i2c, i2c->msg->buf[i2c->msgbuf_ptr++]);
}
static void dc_i2c_next_read(struct dc_i2c *i2c)
{
bool last = (i2c->msgbuf_ptr + 1 == i2c->msg->len);
dc_i2c_cmd(i2c, last ? II_CMD_GET_NOACK : II_CMD_GET_ACK);
}
static void dc_i2c_stop(struct dc_i2c *i2c)
{
i2c->state = STATE_STOP;
if (i2c->last)
dc_i2c_cmd(i2c, II_CMD_STOP);
else
complete(&i2c->done);
}
static u8 dc_i2c_read_byte(struct dc_i2c *i2c)
{
return readb_relaxed(i2c->regs + II_DATA);
}
static void dc_i2c_read_buf(struct dc_i2c *i2c)
{
i2c->msg->buf[i2c->msgbuf_ptr++] = dc_i2c_read_byte(i2c);
dc_i2c_next_read(i2c);
}
static void dc_i2c_set_irq(struct dc_i2c *i2c, int enable)
{
if (enable)
writeb_relaxed(1, i2c->regs + II_INTFLAG_CLEAR);
writeb_relaxed(!!enable, i2c->regs + II_INTENABLE);
}
static int dc_i2c_cmd_status(struct dc_i2c *i2c)
{
u8 cmd = readb_relaxed(i2c->regs + II_COMMAND);
return II_COMMAND_COMPLETION_STATUS(cmd);
}
static void dc_i2c_start_msg(struct dc_i2c *i2c, int first)
{
struct i2c_msg *msg = i2c->msg;
if (!(msg->flags & I2C_M_NOSTART)) {
i2c->state = STATE_START;
dc_i2c_cmd(i2c, first ? II_CMD_START : II_CMD_RESTART);
} else if (msg->flags & I2C_M_RD) {
i2c->state = STATE_READ;
dc_i2c_next_read(i2c);
} else {
i2c->state = STATE_WRITE;
dc_i2c_write_buf(i2c);
}
}
static irqreturn_t dc_i2c_irq(int irq, void *dev_id)
{
struct dc_i2c *i2c = dev_id;
int cmd_status = dc_i2c_cmd_status(i2c);
unsigned long flags;
u8 addr_cmd;
writeb_relaxed(1, i2c->regs + II_INTFLAG_CLEAR);
spin_lock_irqsave(&i2c->lock, flags);
if (cmd_status == II_CMD_STATUS_ACK_BAD
|| cmd_status == II_CMD_STATUS_ABORT) {
i2c->error = -EIO;
complete(&i2c->done);
goto out;
}
switch (i2c->state) {
case STATE_START:
addr_cmd = dc_i2c_addr_cmd(i2c->msg);
dc_i2c_write_byte(i2c, addr_cmd);
i2c->state = STATE_ADDR;
break;
case STATE_ADDR:
if (i2c->msg->flags & I2C_M_RD) {
dc_i2c_next_read(i2c);
i2c->state = STATE_READ;
break;
}
i2c->state = STATE_WRITE;
/* fall through */
case STATE_WRITE:
if (i2c->msgbuf_ptr < i2c->msg->len)
dc_i2c_write_buf(i2c);
else
dc_i2c_stop(i2c);
break;
case STATE_READ:
if (i2c->msgbuf_ptr < i2c->msg->len)
dc_i2c_read_buf(i2c);
else
dc_i2c_stop(i2c);
break;
case STATE_STOP:
i2c->state = STATE_IDLE;
complete(&i2c->done);
break;
}
out:
spin_unlock_irqrestore(&i2c->lock, flags);
return IRQ_HANDLED;
}
static int dc_i2c_xfer_msg(struct dc_i2c *i2c, struct i2c_msg *msg, int first,
int last)
{
unsigned long timeout = msecs_to_jiffies(TIMEOUT_MS);
unsigned long flags;
spin_lock_irqsave(&i2c->lock, flags);
i2c->msg = msg;
i2c->msgbuf_ptr = 0;
i2c->last = last;
i2c->error = 0;
reinit_completion(&i2c->done);
dc_i2c_set_irq(i2c, 1);
dc_i2c_start_msg(i2c, first);
spin_unlock_irqrestore(&i2c->lock, flags);
timeout = wait_for_completion_timeout(&i2c->done, timeout);
dc_i2c_set_irq(i2c, 0);
if (timeout == 0) {
i2c->state = STATE_IDLE;
return -ETIMEDOUT;
}
if (i2c->error)
return i2c->error;
return 0;
}
static int dc_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
{
struct dc_i2c *i2c = adap->algo_data;
int i, ret;
for (i = 0; i < num; i++) {
ret = dc_i2c_xfer_msg(i2c, &msgs[i], i == 0, i == num - 1);
if (ret)
return ret;
}
return num;
}
static int dc_i2c_init_hw(struct dc_i2c *i2c)
{
unsigned long clk_rate = clk_get_rate(i2c->clk);
unsigned int clocktime;
writeb_relaxed(II_CONTROL_LOCAL_RESET, i2c->regs + II_CONTROL);
udelay(100);
writeb_relaxed(0, i2c->regs + II_CONTROL);
udelay(100);
clocktime = DIV_ROUND_UP(clk_rate, 64 * i2c->frequency);
if (clocktime < 1 || clocktime > 0xff) {
dev_err(i2c->dev, "can't set bus speed of %u Hz\n",
i2c->frequency);
return -EINVAL;
}
writeb_relaxed(clocktime - 1, i2c->regs + II_CLOCKTIME);
return 0;
}
static u32 dc_i2c_func(struct i2c_adapter *adap)
{
return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_NOSTART;
}
static const struct i2c_algorithm dc_i2c_algorithm = {
.master_xfer = dc_i2c_xfer,
.functionality = dc_i2c_func,
};
static int dc_i2c_probe(struct platform_device *pdev)
{
struct device_node *np = pdev->dev.of_node;
struct dc_i2c *i2c;
struct resource *r;
int ret = 0, irq;
i2c = devm_kzalloc(&pdev->dev, sizeof(struct dc_i2c), GFP_KERNEL);
if (!i2c)
return -ENOMEM;
if (of_property_read_u32(pdev->dev.of_node, "clock-frequency",
&i2c->frequency))
i2c->frequency = DEFAULT_FREQ;
i2c->dev = &pdev->dev;
platform_set_drvdata(pdev, i2c);
spin_lock_init(&i2c->lock);
init_completion(&i2c->done);
i2c->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(i2c->clk))
return PTR_ERR(i2c->clk);
r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
i2c->regs = devm_ioremap_resource(&pdev->dev, r);
if (IS_ERR(i2c->regs))
return PTR_ERR(i2c->regs);
irq = platform_get_irq(pdev, 0);
if (irq < 0)
return irq;
ret = devm_request_irq(&pdev->dev, irq, dc_i2c_irq, 0,
dev_name(&pdev->dev), i2c);
if (ret < 0)
return ret;
strlcpy(i2c->adap.name, "Conexant Digicolor I2C adapter",
sizeof(i2c->adap.name));
i2c->adap.owner = THIS_MODULE;
i2c->adap.algo = &dc_i2c_algorithm;
i2c->adap.dev.parent = &pdev->dev;
i2c->adap.dev.of_node = np;
i2c->adap.algo_data = i2c;
ret = dc_i2c_init_hw(i2c);
if (ret)
return ret;
ret = clk_prepare_enable(i2c->clk);
if (ret < 0)
return ret;
ret = i2c_add_adapter(&i2c->adap);
if (ret < 0) {
clk_unprepare(i2c->clk);
return ret;
}
return 0;
}
static int dc_i2c_remove(struct platform_device *pdev)
{
struct dc_i2c *i2c = platform_get_drvdata(pdev);
i2c_del_adapter(&i2c->adap);
clk_disable_unprepare(i2c->clk);
return 0;
}
static const struct of_device_id dc_i2c_match[] = {
{ .compatible = "cnxt,cx92755-i2c" },
{ },
};
static struct platform_driver dc_i2c_driver = {
.probe = dc_i2c_probe,
.remove = dc_i2c_remove,
.driver = {
.name = "digicolor-i2c",
.of_match_table = dc_i2c_match,
},
};
module_platform_driver(dc_i2c_driver);
MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
MODULE_DESCRIPTION("Conexant Digicolor I2C master driver");
MODULE_LICENSE("GPL v2");

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