serial: stm32: use mapbase instead of membase for DMA
Building this driver with a 64-bit dma_addr_t type results in a compiler warning: drivers/tty/serial/stm32-usart.c: In function 'stm32_of_dma_rx_probe': drivers/tty/serial/stm32-usart.c:746:20: error: cast from pointer to integer of different size [-Werror=pointer-to-int-cast] drivers/tty/serial/stm32-usart.c: In function 'stm32_of_dma_tx_probe': drivers/tty/serial/stm32-usart.c:818:20: error: cast from pointer to integer of different size [-Werror=pointer-to-int-cast] While the type conversion here is harmless, this hints at a different problem: we pass an __iomem pointer into a DMA engine, which expects a phys_addr_t. This happens to work because stm32 has no MMU and ioremap() is an identity mapping here, but it's still an incorrect API use. Using dma_addr_t is doubly wrong here, because that would be the result of dma_map_single() rather than the physical address. Using the mapbase instead fixes multiple issues: - the warning is gone - we don't go through ioremap in error - the cast is gone, making it use the correct resource_size_t/phys_addr_t type in the process. Fixes: 34891872 ("serial: stm32: adding dma support") Signed-off-by: NArnd Bergmann <arnd@arndb.de> Reviewed-by: NGerald Baeza <gerald.baeza@st.com> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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