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path: root/drivers/net/can/c_can/c_can.h
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* can: c_can: Add support for START pulse in RAMINIT sequenceRoger Quadros2014-11-17
| | | | | | | | | Some SoCs e.g. (TI DRA7xx) need a START pulse to start the RAMINIT sequence i.e. START bit must be set and cleared before checking for the DONE bit status. Signed-off-by: Roger Quadros <rogerq@ti.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
* can: c_can: Add syscon/regmap RAMINIT mechanismRoger Quadros2014-11-17
| | | | | | | | | | | | | | | | Some TI SoCs like DRA7 have a RAMINIT register specification different from the other AMxx SoCs and as expected by the existing driver. To add more insanity, this register is shared with other IPs like DSS, PCIe and PWM. Provides a more generic mechanism to specify the RAMINIT register location and START/DONE bit position and use the syscon/regmap framework to access the register. Signed-off-by: Roger Quadros <rogerq@ti.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
* can: c_can: Add RAMINIT register information to driver dataRoger Quadros2014-11-17
| | | | | | | | Some platforms (e.g. TI) need special RAMINIT register handling. Provide a way to store RAMINIT register description in driver data. Signed-off-by: Roger Quadros <rogerq@ti.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
* can: c_can: Introduce c_can_driver_data structureRoger Quadros2014-11-17
| | | | | | | | | | | | We want to have more data than just can_dev_id to be present in the driver data e.g. TI platforms need RAMINIT register description. Introduce the c_can_driver_data structure and move the can_dev_id into it. Tidy up the way it is used on probe(). Signed-off-by: Roger Quadros <rogerq@ti.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
* can: c_can: add hwinit support for non-TI devicesPavel Machek2014-05-19
| | | | | | | | | | Non-TI chips (including socfpga) needs different raminit sequence. Implement it. Tested-by: Thor Thayer <tthayer@altera.com> Signed-off-by: Thor Thayer <tthayer@altera.com> Signed-off-by: Pavel Machek <pavel@denx.de> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
* can: c_can: Add and make use of 32-bit accesses functionsPavel Machek2014-05-19
| | | | | | | | | | | Add helpers for 32-bit accesses and replace open-coded 32-bit access with calls to helpers. Minimum changes are done to the pci case, as I don't have access to that hardware. Tested-by: Thor Thayer <tthayer@altera.com> Signed-off-by: Thor Thayer <tthayer@altera.com> Signed-off-by: Pavel Machek <pavel@denx.de> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
* can: c_can: make {read,write}_reg functions constPavel Machek2014-05-19
| | | | | | | | | This patch makes the {read,write}_reg functions const, this is a preparation to make use of {read,write}_reg in the hwinit callback. Signed-off-by: Thor Thayer <tthayer@altera.com> Signed-off-by: Pavel Machek <pavel@denx.de> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
* can: c_can: use proper type for 'instance'Wolfram Sang2014-04-24
| | | | | | | | | | Commit 6439fbce1075 (can: c_can: fix error checking of priv->instance in probe()) found the warning but applied a suboptimal solution. Since, both pdev->id and of_alias_get_id() return integers, it makes sense to convert the variable to an integer and avoid the cast. Signed-off-by: Wolfram Sang <wsa@sang-engineering.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
* can: c_can: Speed up tx buffer invalidationThomas Gleixner2014-04-24
| | | | | | | | | | | It's suffcient to kill the TXIE bit in the message control register even if the documentation of C and D CAN says that it's not allowed to do that while MSGVAL is set. Reality tells a different story and this change gives us another 2% of CPU back for not waiting on I/O. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Alexander Stein <alexander.stein@systec-electronic.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
* can: c_can: Remove tx lockingThomas Gleixner2014-04-24
| | | | | | | | | | | | | | | | | Mark suggested to use one IF for the softirq and the other for the xmit function to avoid the xmit lock. That requires to write the frame into the interface first, then handle the echo skb and store the dlc before committing the TX request to the message ram. We use an atomic to handle the active buffers instead of reading the MSGVAL register as thats way faster especially on PCH/x86. Suggested-by: Mark <mark5@del-llc.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Alexander Stein <alexander.stein@systec-electronic.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
* can: c_can: Cleanup c_can_write_msg_object()Thomas Gleixner2014-04-24
| | | | | | | | | | | Remove the MASK from the TX transfer side. Make the code readable and get rid of the annoying IFX_WRITE_XXX_16BIT macros which are just obfuscating the code. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Alexander Stein <alexander.stein@systec-electronic.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
* can: c_can: Work around C_CAN RX wreckageThomas Gleixner2014-04-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Alexander reported that the new optimized handling of the RX fifo causes random packet loss on Intel PCH C_CAN hardware. After a few fruitless debugging sessions I got hold of a PCH (eg20t) afflicted system. That machine does not have the CAN interface wired up, but it was possible to reproduce the issue with the HW loopback mode. As Alexander observed correctly, clearing the NewDat flag along with reading out the message buffer causes that issue on C_CAN, while D_CAN handles that correctly. Instead of restoring the original message buffer handling horror the following workaround solves the issue: transfer buffer to IF without clearing the NewDat handle the message clear NewDat bit That's similar to the original code but conditional for C_CAN. I really wonder why all user manuals (C_CAN, Intel PCH and some more) recommend to clear the NewDat bit right away. The knows it all Oracle operated by Gurgle does not unearth any useful information either. I simply cannot believe that we are the first to uncover that HW issue. Reported-and-tested-by: Alexander Stein <alexander.stein@systec-electronic.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
* can: c_can: Get rid of pointless interruptsThomas Gleixner2014-04-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | The driver handles pointlessly TWO interrupts per packet. The reason is that it enables the status interrupt which fires for each rx and tx packet and it enables the per message object interrupts as well. The status interrupt merily acks or in case of D_CAN ignores the TX/RX state and then the message object interrupt fires. The message objects interrupts are only useful if all message objects have hardware filters activated. But we don't have that and its not simple to implement in that driver without rewriting it completely. So we can ditch the message object interrupts and handle the RX/TX right away from the status interrupt. Instead of TWO we handle ONE. Note: We must keep the TXIE/RXIE bits in the message buffers because the status interrupt alone is not reliable enough in corner cases. If we ever have the need for HW filtering, then this code needs a complete overhaul and we can think about it then. For now we prefer a lower interrupt load. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Alexander Stein <alexander.stein@systec-electronic.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
* can: c_can: Store dlc privateThomas Gleixner2014-04-01
| | | | | | | | | | | We can avoid the HW access in TX cleanup path for retrieving the DLC of the sent package if we store the DLC in a private array. Ideally this should be handled in the can_echo_skb functions, but I leave that exercise to the CAN folks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
* can: c_can: Provide protection in the xmit pathThomas Gleixner2014-04-01
| | | | | | | | | | | | | | | | | | | | The network core does not serialize the access to the hardware. The xmit related code lets the following happen: CPU0 CPU1 interrupt() do_poll() c_can_do_tx() Fiddle with HW and xmit() internal data Fiddle with HW and internal data due the complete lack of serialization. Add proper locking. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
* can: c_can: Add d_can raminit supportAnilKumar Ch2012-11-27
| | | | | | | | | | | | | | | | | | | | | | | | Add D_CAN raminit support to C_CAN driver to enable D_CAN RAM, which holds all the message objects during transmission or receiving of data. This initialization/de-initialization should be done in synchronous with D_CAN clock. In case of AM335X-EVM (current user of D_CAN driver) message RAM is controlled through control module register for both instances. So control module register details is required to initialization or de-initialization of message RAM according to instance number. Control module memory resource is obtained from D_CAN dt node and instance number obtained from device tree aliases node. This patch was tested on AM335x-EVM along with pinctrl data addition patch, d_can dt aliases addition and control module data addition. pinctrl data addition is not added to am335x-evm.dts (only supports CPLD profile#0) because d_can1 is supported under CPLD profile#1. Signed-off-by: AnilKumar Ch <anilkumar@ti.com> [mkl: fix instance for non DT in probe, cleaned up raminit] Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
* can: c_can: Add d_can suspend resume supportAnilKumar Ch2012-09-21
| | | | | | | | | Adds suspend resume support to DCAN driver which enables DCAN power down mode bit (PDR). Then DCAN will ack the local power-down mode by setting PDA bit in STATUS register. Signed-off-by: AnilKumar Ch <anilkumar@ti.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
* can: c_can: Add runtime PM support to Bosch C_CAN/D_CAN controllerAnilKumar Ch2012-09-21
| | | | | | | | | Add Runtime PM support to C_CAN/D_CAN controller. The runtime PM APIs control clocks for C_CAN/D_CAN IP and prevent access to the register of C_CAN/D_CAN IP when clock is turned off. Signed-off-by: AnilKumar Ch <anilkumar@ti.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
* can: c_can: Modify c_can device namesAnilKumar Ch2012-09-21
| | | | | | | | | | | Modify c_can device names from *_CAN_DEVTYPE to BOSCH_*_CAN to make use of same names for array indexes in c_can_id_table[] as well as device names. This patch also add indexes to c_can_id_table array. Signed-off-by: AnilKumar Ch <anilkumar@ti.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
* can: c_can: Add support for Bosch D_CAN controllerAnilKumar Ch2012-06-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds the support for D_CAN controller driver to the existing C_CAN driver. Bosch D_CAN controller is a full-CAN implementation which is compliant to CAN protocol version 2.0 part A and B. Bosch D_CAN user manual can be obtained from: http://www.semiconductors.bosch.de/media/en/pdf/ ipmodules_1/can/d_can_users_manual_111.pdf A new array is added for accessing the d_can registers, according to d_can controller register space. Current D_CAN implementation has following limitations, this is done to avoid large changes to the C_CAN driver. 1. Message objects are limited to 32, 16 for RX and 16 for TX. C_CAN IP supports upto 32 message objects but in case of D_CAN we can configure upto 128 message objects. 2. Using two 16bit reads/writes for accessing the 32bit D_CAN registers. 3. These patches have been tested on little endian machine, there might be some hidden endian-related issues due to the nature of the accesses (32-bit registers accessed as 2 16-bit registers). However, I do not have a big-endian D_CAN implementation to confirm. Signed-off-by: AnilKumar Ch <anilkumar@ti.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
* can: c_can: Move overlay structure to array with offset as indexAnilKumar Ch2012-06-07
| | | | | | | | | | | | | | c_can uses overlay structure for accessing c_can module registers. With this kind of implementation it is difficult to add one more ip which is similar to c_can in functionality but different register offsets. This patch changes the overlay structure implementation to an array with register offset as index. This way we can overcome the above limitation. Signed-off-by: AnilKumar Ch <anilkumar@ti.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
* can: c_can: fix an interrupt thrash issue with c_can driverAnilKumar Ch2012-06-03
| | | | | | | | | | | | | | | | | | | | This patch fixes an interrupt thrash issue with c_can driver. In c_can_isr() function interrupts are disabled and enabled only in c_can_poll() function. c_can_isr() & c_can_poll() both read the irqstatus flag. However, irqstatus is always read as 0 in c_can_poll() because all C_CAN interrupts are disabled in c_can_isr(). This causes all interrupts to be re-enabled in c_can_poll() which in turn causes another interrupt since the event is not really handled. This keeps happening causing a flood of interrupts. To fix this, read the irqstatus register in isr and use the same cached value in the poll function. Cc: stable@kernel.org # 2.6.39+ Signed-off-by: AnilKumar Ch <anilkumar@ti.com> Acked-by: Wolfgang Grandegger <wg@grandegger.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
* can: c_can: Added support for Bosch C_CAN controllerBhupesh Sharma2011-02-14
Bosch C_CAN controller is a full-CAN implementation which is compliant to CAN protocol version 2.0 part A and B. Bosch C_CAN user manual can be obtained from: http://www.semiconductors.bosch.de/media/en/pdf/ipmodules_1/c_can/users_manual_c_can.pdf This patch adds the support for this controller. The following are the design choices made while writing the controller driver: 1. Interface Register set IF1 has be used only in the current design. 2. Out of the 32 Message objects available, 16 are kept aside for RX purposes and the rest for TX purposes. 3. NAPI implementation is such that both the TX and RX paths function in polling mode. Signed-off-by: Bhupesh Sharma <bhupesh.sharma@st.com> Signed-off-by: David S. Miller <davem@davemloft.net>