diff options
author | Gabriel Somlo | 2021-01-12 12:31:40 -0500 |
---|---|---|
committer | Stafford Horne | 2021-01-14 09:52:54 +0900 |
commit | 9d93a9e8aab3f82b6742dd034a6a81d4025cd82e (patch) | |
tree | 8846dbce998521fc20ad7212a5397dfef3dcc4f5 /drivers/soc/litex | |
parent | 131172a4a8ce3fccfd4a9f0f8b3c0d0e59222f1d (diff) |
drivers/soc/litex: move generic accessors to litex.h
Move generic LiteX CSR (MMIO) register accessors to litex.h and
declare them as "static inline", in preparation for supporting
32-bit CSR subregisters and 64-bit CPUs.
NOTE: this is a non-functional change.
Signed-off-by: Gabriel Somlo <gsomlo@gmail.com>
Signed-off-by: Stafford Horne <shorne@gmail.com>
Diffstat (limited to 'drivers/soc/litex')
-rw-r--r-- | drivers/soc/litex/litex_soc_ctrl.c | 73 |
1 files changed, 0 insertions, 73 deletions
diff --git a/drivers/soc/litex/litex_soc_ctrl.c b/drivers/soc/litex/litex_soc_ctrl.c index 1217cafdfd4d..65977526d68e 100644 --- a/drivers/soc/litex/litex_soc_ctrl.c +++ b/drivers/soc/litex/litex_soc_ctrl.c @@ -16,79 +16,6 @@ #include <linux/errno.h> #include <linux/io.h> -/* - * LiteX SoC Generator, depending on the configuration, can split a single - * logical CSR (Control&Status Register) into a series of consecutive physical - * registers. - * - * For example, in the configuration with 8-bit CSR Bus, 32-bit aligned (the - * default one for 32-bit CPUs) a 32-bit logical CSR will be generated as four - * 32-bit physical registers, each one containing one byte of meaningful data. - * - * For details see: https://github.com/enjoy-digital/litex/wiki/CSR-Bus - * - * The purpose of `litex_set_reg`/`litex_get_reg` is to implement the logic - * of writing to/reading from the LiteX CSR in a single place that can be - * then reused by all LiteX drivers. - */ - -/** - * litex_set_reg() - Writes the value to the LiteX CSR (Control&Status Register) - * @reg: Address of the CSR - * @reg_size: The width of the CSR expressed in the number of bytes - * @val: Value to be written to the CSR - * - * In the currently supported LiteX configuration (8-bit CSR Bus, 32-bit aligned), - * a 32-bit LiteX CSR is generated as 4 consecutive 32-bit physical registers, - * each one containing one byte of meaningful data. - * - * This function splits a single possibly multi-byte write into a series of - * single-byte writes with a proper offset. - */ -void litex_set_reg(void __iomem *reg, unsigned long reg_size, - unsigned long val) -{ - unsigned long shifted_data, shift, i; - - for (i = 0; i < reg_size; ++i) { - shift = ((reg_size - i - 1) * LITEX_SUBREG_SIZE_BIT); - shifted_data = val >> shift; - - WRITE_LITEX_SUBREGISTER(shifted_data, reg, i); - } -} -EXPORT_SYMBOL_GPL(litex_set_reg); - -/** - * litex_get_reg() - Reads the value of the LiteX CSR (Control&Status Register) - * @reg: Address of the CSR - * @reg_size: The width of the CSR expressed in the number of bytes - * - * Return: Value read from the CSR - * - * In the currently supported LiteX configuration (8-bit CSR Bus, 32-bit aligned), - * a 32-bit LiteX CSR is generated as 4 consecutive 32-bit physical registers, - * each one containing one byte of meaningful data. - * - * This function generates a series of single-byte reads with a proper offset - * and joins their results into a single multi-byte value. - */ -unsigned long litex_get_reg(void __iomem *reg, unsigned long reg_size) -{ - unsigned long shifted_data, shift, i; - unsigned long result = 0; - - for (i = 0; i < reg_size; ++i) { - shifted_data = READ_LITEX_SUBREGISTER(reg, i); - - shift = ((reg_size - i - 1) * LITEX_SUBREG_SIZE_BIT); - result |= (shifted_data << shift); - } - - return result; -} -EXPORT_SYMBOL_GPL(litex_get_reg); - #define SCRATCH_REG_OFF 0x04 #define SCRATCH_REG_VALUE 0x12345678 #define SCRATCH_TEST_VALUE 0xdeadbeef |