aspeed/i2c: Add support for DMA transfers

The I2C controller of the Aspeed AST2500 and AST2600 SoCs supports DMA
transfers to and from DRAM.

A pair of registers defines the buffer address and the length of the
DMA transfer. The address should be aligned on 4 bytes and the maximum
length should not exceed 4K. The receive or transmit DMA transfer can
then be initiated with specific bits in the Command/Status register of
the controller.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Tested-by: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-id: 20191119141211.25716-5-clg@kaod.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This commit is contained in:
Cédric Le Goater 2019-11-19 15:11:58 +01:00 committed by Peter Maydell
parent 95b56e173e
commit 545d6bef70
4 changed files with 138 additions and 3 deletions

View file

@ -52,6 +52,8 @@ typedef struct AspeedI2CBus {
uint32_t cmd;
uint32_t buf;
uint32_t pool_ctrl;
uint32_t dma_addr;
uint32_t dma_len;
} AspeedI2CBus;
typedef struct AspeedI2CState {
@ -66,6 +68,8 @@ typedef struct AspeedI2CState {
uint8_t pool[ASPEED_I2C_MAX_POOL_SIZE];
AspeedI2CBus busses[ASPEED_I2C_NR_BUSSES];
MemoryRegion *dram_mr;
AddressSpace dram_as;
} AspeedI2CState;
#define ASPEED_I2C_CLASS(klass) \
@ -85,6 +89,7 @@ typedef struct AspeedI2CClass {
hwaddr pool_base;
uint8_t *(*bus_pool_base)(AspeedI2CBus *);
bool check_sram;
bool has_dma;
} AspeedI2CClass;