leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity

ARM: 5678/1: SSP/SPI PL022 polarity terminology fix

Browse Source 
The definition of the SPI clock phase for the Motorola mode of
the PL022 driver was incorrect: the spec had been interpreted as
data being recieved on rising or falling edge of the clocks while
the correct interpretation is that data can be recieved on the
first or second edge transition, falling or rising depending on
the polarity setting.

Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Linus Walleij 2009-08-15 15:12:05 +01:00 committed by Russell King
parent a2ca00ea93
commit ee2b805c8e
3 changed files with 9 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
arch/arm/mach-u300/spi.c
View File

@ -48,7 +48,7 @@ struct pl022_config_chip dummy_chip_info = {
.data_size = SSP_DATA_BITS_8, /* used to be 12 in some default */
.rx_lev_trig = SSP_RX_1_OR_MORE_ELEM,
.tx_lev_trig = SSP_TX_1_OR_MORE_EMPTY_LOC,
.clk_phase = SSP_CLK_FALLING_EDGE,
.clk_phase = SSP_CLK_SECOND_EDGE,
.clk_pol = SSP_CLK_POL_IDLE_LOW,
.ctrl_len = SSP_BITS_12,
.wait_state = SSP_MWIRE_WAIT_ZERO,

8
drivers/spi/amba-pl022.c
View File

@ -534,7 +534,7 @@ static void restore_state(struct pl022 *pl022)
GEN_MASK_BITS(SSP_DATA_BITS_12, SSP_CR0_MASK_DSS, 0) | \
GEN_MASK_BITS(SSP_MICROWIRE_CHANNEL_FULL_DUPLEX, SSP_CR0_MASK_HALFDUP, 5) | \
GEN_MASK_BITS(SSP_CLK_POL_IDLE_LOW, SSP_CR0_MASK_SPO, 6) | \
GEN_MASK_BITS(SSP_CLK_FALLING_EDGE, SSP_CR0_MASK_SPH, 7) | \
GEN_MASK_BITS(SSP_CLK_SECOND_EDGE, SSP_CR0_MASK_SPH, 7) | \
GEN_MASK_BITS(NMDK_SSP_DEFAULT_CLKRATE, SSP_CR0_MASK_SCR, 8) | \
GEN_MASK_BITS(SSP_BITS_8, SSP_CR0_MASK_CSS, 16) | \
GEN_MASK_BITS(SSP_INTERFACE_MOTOROLA_SPI, SSP_CR0_MASK_FRF, 21) \
@ -1249,8 +1249,8 @@ static int verify_controller_parameters(struct pl022 *pl022,
return -EINVAL;
}
if (chip_info->iface == SSP_INTERFACE_MOTOROLA_SPI) {
if ((chip_info->clk_phase != SSP_CLK_RISING_EDGE)
&& (chip_info->clk_phase != SSP_CLK_FALLING_EDGE)) {
if ((chip_info->clk_phase != SSP_CLK_FIRST_EDGE)
&& (chip_info->clk_phase != SSP_CLK_SECOND_EDGE)) {
dev_err(chip_info->dev,
"Clock Phase is configured incorrectly\n");
return -EINVAL;
@ -1487,7 +1487,7 @@ static int pl022_setup(struct spi_device *spi)
chip_info->data_size = SSP_DATA_BITS_12;
chip_info->rx_lev_trig = SSP_RX_1_OR_MORE_ELEM;
chip_info->tx_lev_trig = SSP_TX_1_OR_MORE_EMPTY_LOC;
chip_info->clk_phase = SSP_CLK_FALLING_EDGE;
chip_info->clk_phase = SSP_CLK_SECOND_EDGE;
chip_info->clk_pol = SSP_CLK_POL_IDLE_LOW;
chip_info->ctrl_len = SSP_BITS_8;
chip_info->wait_state = SSP_MWIRE_WAIT_ZERO;

8
include/linux/amba/pl022.h
View File

@ -136,12 +136,12 @@ enum ssp_tx_level_trig {
/**
* enum SPI Clock Phase - clock phase (Motorola SPI interface only)
* @SSP_CLK_RISING_EDGE: Receive data on rising edge
* @SSP_CLK_FALLING_EDGE: Receive data on falling edge
* @SSP_CLK_FIRST_EDGE: Receive data on first edge transition (actual direction depends on polarity)
* @SSP_CLK_SECOND_EDGE: Receive data on second edge transition (actual direction depends on polarity)
*/
enum ssp_spi_clk_phase {
SSP_CLK_RISING_EDGE,
SSP_CLK_FALLING_EDGE
SSP_CLK_FIRST_EDGE,
SSP_CLK_SECOND_EDGE
};
/**