From: Linus Walleij <linus.walleij-0IS4wlFg1OjSUeElwK9/Pw@public.gmane.org>
To: linux-arm-kernel-xIg/pKzrS19vn6HldHNs0ANdhmdF6hFW@public.gmane.org,
spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org
Cc: Linus Walleij <linus.walleij-0IS4wlFg1OjSUeElwK9/Pw@public.gmane.org>
Subject: [PATCH] SSP/SPI PL022 polarity terminology fix
Date: Sat, 15 Aug 2009 16:11:12 +0200 [thread overview]
Message-ID: <1250345472-30932-1-git-send-email-linus.walleij@stericsson.com> (raw)
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-0IS4wlFg1OjSUeElwK9/Pw@public.gmane.org>
----
This depends on the recent board data configuration for U300 being
applied first and I submit it to Russells patch tracker so that
it comes in through the ARM tree if there are not objections.
---
arch/arm/mach-u300/spi.c | 2 +-
drivers/spi/amba-pl022.c | 8 ++++----
include/linux/amba/pl022.h | 8 ++++----
3 files changed, 9 insertions(+), 9 deletions(-)
diff --git a/arch/arm/mach-u300/spi.c b/arch/arm/mach-u300/spi.c
index a58c9ea..51cb950 100644
--- a/arch/arm/mach-u300/spi.c
+++ b/arch/arm/mach-u300/spi.c
@@ -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,
diff --git a/drivers/spi/amba-pl022.c b/drivers/spi/amba-pl022.c
index da76797..35521af 100644
--- a/drivers/spi/amba-pl022.c
+++ b/drivers/spi/amba-pl022.c
@@ -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;
diff --git a/include/linux/amba/pl022.h b/include/linux/amba/pl022.h
index dcad0ff..e4836c6 100644
--- a/include/linux/amba/pl022.h
+++ b/include/linux/amba/pl022.h
@@ -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
};
/**
--
1.6.2.1
------------------------------------------------------------------------------
Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day
trial. Simplify your report design, integration and deployment - and focus on
what you do best, core application coding. Discover what's new with
Crystal Reports now. http://p.sf.net/sfu/bobj-july
reply other threads:[~2009-08-15 14:11 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1250345472-30932-1-git-send-email-linus.walleij@stericsson.com \
--to=linus.walleij-0is4wlfg1ojsueelwk9/pw@public.gmane.org \
--cc=linux-arm-kernel-xIg/pKzrS19vn6HldHNs0ANdhmdF6hFW@public.gmane.org \
--cc=spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).