[U-Boot] [PATCH v2 0/2] SPI: mxc_spi: slave initialisation fixes

[U-Boot] [PATCH v2 0/2] SPI: mxc_spi: slave initialisation fixes

[Markus Niebel]

From: Markus Niebel <Markus.Niebel@tq-group.com>

current implementation of the mxc_spi host driver gives issues,
if using more than one slave on the same bus. These patches try
to improve this use case.

They were tested on a TQMa6S (i.MX6S) with a custom mainboard
using two slave devices in SPI MODE 0 and 3, on of the devices
uses gpio based chip select the other hardware base chip select.

Markus Niebel (2):
  SPI: mxc_spi: remove second reset from ECSPI config handler
  SPI: mxc_spi: delay initialisation until claim bus

 drivers/spi/mxc_spi.c | 40 +++++++++++++++++++++-------------------
 1 file changed, 21 insertions(+), 19 deletions(-)

-- 

Changes since v1:

- fix typo

2.1.1

[U-Boot] [PATCH v2 1/2] SPI: mxc_spi: remove second reset from ECSPI config handler

[Markus Niebel]

From: Markus Niebel <Markus.Niebel@tq-group.com>

the second reset prevents other registers to be written.
This will prevent to have the correct signal levels for
SCLK before writing to the config reg in spi_xchg_single.

Tested with GPIO based chipselect and SPI_MODE_3 on i.MX6S

Signed-off-by: Markus Niebel <Markus.Niebel@tq-group.com>
---
Changes since v1:
- rebase to current master

 drivers/spi/mxc_spi.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/drivers/spi/mxc_spi.c b/drivers/spi/mxc_spi.c
index 026f680..555b34f 100644
--- a/drivers/spi/mxc_spi.c
+++ b/drivers/spi/mxc_spi.c
@@ -168,9 +168,6 @@ static s32 spi_cfg_mxc(struct mxc_spi_slave *mxcs, unsigned int cs,
 	reg_ctrl = (reg_ctrl & ~MXC_CSPICTRL_POSTDIV(0x0F)) |
 		MXC_CSPICTRL_POSTDIV(post_div);
 
-	/* We need to disable SPI before changing registers */
-	reg_ctrl &= ~MXC_CSPICTRL_EN;
-
 	if (mode & SPI_CS_HIGH)
 		ss_pol = 1;
 
-- 
2.1.1

[U-Boot] [PATCH v2 2/2] SPI: mxc_spi: delay initialisation until claim bus

[Markus Niebel]

From: Markus Niebel <Markus.Niebel@tq-group.com>

it is not correct to init for a specific slave in spi_setup_slave.
instead buffer the values and delay init until spi_claim_bus.

Signed-off-by: Markus Niebel <Markus.Niebel@tq-group.com>
---
Changes since v1:
- rebase to current master

 drivers/spi/mxc_spi.c | 37 +++++++++++++++++++++----------------
 1 file changed, 21 insertions(+), 16 deletions(-)

diff --git a/drivers/spi/mxc_spi.c b/drivers/spi/mxc_spi.c
index 555b34f..e04a30f 100644
--- a/drivers/spi/mxc_spi.c
+++ b/drivers/spi/mxc_spi.c
@@ -48,6 +48,8 @@ struct mxc_spi_slave {
 #endif
 	int		gpio;
 	int		ss_pol;
+	unsigned int	max_hz;
+	unsigned int	mode;
 };
 
 static inline struct mxc_spi_slave *to_mxc_spi_slave(struct spi_slave *slave)
@@ -82,12 +84,13 @@ u32 get_cspi_div(u32 div)
 }
 
 #ifdef MXC_CSPI
-static s32 spi_cfg_mxc(struct mxc_spi_slave *mxcs, unsigned int cs,
-		unsigned int max_hz, unsigned int mode)
+static s32 spi_cfg_mxc(struct mxc_spi_slave *mxcs, unsigned int cs)
 {
 	unsigned int ctrl_reg;
 	u32 clk_src;
 	u32 div;
+	unsigned int max_hz = mxcs->max_hz;
+	unsigned int mode = mxcs->mode;
 
 	clk_src = mxc_get_clock(MXC_CSPI_CLK);
 
@@ -119,19 +122,15 @@ static s32 spi_cfg_mxc(struct mxc_spi_slave *mxcs, unsigned int cs,
 #endif
 
 #ifdef MXC_ECSPI
-static s32 spi_cfg_mxc(struct mxc_spi_slave *mxcs, unsigned int cs,
-		unsigned int max_hz, unsigned int mode)
+static s32 spi_cfg_mxc(struct mxc_spi_slave *mxcs, unsigned int cs)
 {
 	u32 clk_src = mxc_get_clock(MXC_CSPI_CLK);
 	s32 reg_ctrl, reg_config;
 	u32 ss_pol = 0, sclkpol = 0, sclkpha = 0, sclkctl = 0;
 	u32 pre_div = 0, post_div = 0;
 	struct cspi_regs *regs = (struct cspi_regs *)mxcs->base;
-
-	if (max_hz == 0) {
-		printf("Error: desired clock is 0\n");
-		return -1;
-	}
+	unsigned int max_hz = mxcs->max_hz;
+	unsigned int mode = mxcs->mode;
 
 	/*
 	 * Reset SPI and set all CSs to master mode, if toggling
@@ -408,6 +407,11 @@ struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
 	if (bus >= ARRAY_SIZE(spi_bases))
 		return NULL;
 
+	if (max_hz == 0) {
+		printf("Error: desired clock is 0\n");
+		return NULL;
+	}
+
 	mxcs = spi_alloc_slave(struct mxc_spi_slave, bus, cs);
 	if (!mxcs) {
 		puts("mxc_spi: SPI Slave not allocated !\n");
@@ -423,13 +427,9 @@ struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
 	}
 
 	mxcs->base = spi_bases[bus];
+	mxcs->max_hz = max_hz;
+	mxcs->mode = mode;
 
-	ret = spi_cfg_mxc(mxcs, cs, max_hz, mode);
-	if (ret) {
-		printf("mxc_spi: cannot setup SPI controller\n");
-		free(mxcs);
-		return NULL;
-	}
 	return &mxcs->slave;
 }
 
@@ -442,12 +442,17 @@ void spi_free_slave(struct spi_slave *slave)
 
 int spi_claim_bus(struct spi_slave *slave)
 {
+	int ret;
 	struct mxc_spi_slave *mxcs = to_mxc_spi_slave(slave);
 	struct cspi_regs *regs = (struct cspi_regs *)mxcs->base;
 
 	reg_write(&regs->rxdata, 1);
 	udelay(1);
-	reg_write(&regs->ctrl, mxcs->ctrl_reg);
+	ret = spi_cfg_mxc(mxcs, slave->cs);
+	if (ret) {
+		printf("mxc_spi: cannot setup SPI controller\n");
+		return ret;
+	}
 	reg_write(&regs->period, MXC_CSPIPERIOD_32KHZ);
 	reg_write(&regs->intr, 0);
 
-- 
2.1.1

[U-Boot] [PATCH v2 0/2] SPI: mxc_spi: slave initialisation fixes

[Jagan Teki]

On 23 October 2014 19:39, Markus Niebel <list-09_u-boot@tqsc.de> wrote:
> From: Markus Niebel <Markus.Niebel@tq-group.com>
>
> current implementation of the mxc_spi host driver gives issues,
> if using more than one slave on the same bus. These patches try
> to improve this use case.
>
> They were tested on a TQMa6S (i.MX6S) with a custom mainboard
> using two slave devices in SPI MODE 0 and 3, on of the devices
> uses gpio based chip select the other hardware base chip select.
>
> Markus Niebel (2):
>   SPI: mxc_spi: remove second reset from ECSPI config handler
>   SPI: mxc_spi: delay initialisation until claim bus
>
>  drivers/spi/mxc_spi.c | 40 +++++++++++++++++++++-------------------
>  1 file changed, 21 insertions(+), 19 deletions(-)

Applied to u-boot-spi/master

thanks!
-- 
Jagan.