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[U-Boot,u-boot,V4] spi/arm-pl022: Add support for ARM PL022 spi controller

Message ID 1370591065-8258-1-git-send-email-armando.visconti@st.com
State Superseded
Delegated to: Jagannadha Sutradharudu Teki
Headers show

Commit Message

Armando Visconti June 7, 2013, 7:44 a.m. UTC
This patch adds the support for the ARM PL022 SPI controller for the standard
variant (0x00041022), which has a 16bit wide and 8 locations deep TX/RX FIFO.

Signed-off-by: Armando Visconti <armando.visconti@st.com>
Signed-off-by: Vipin Kumar <vipin.kumar@st.com>
Acked-by: Stefan Roese <sr@denx.de>
---
v3->v4
Just removed all warnings when running checkpatch.
Didn't find Jagan's feedback... So, pls, let me know if we
need to change anything else...

Armando

 drivers/spi/Makefile    |   1 +
 drivers/spi/pl022_spi.c | 310 ++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 311 insertions(+)
 create mode 100644 drivers/spi/pl022_spi.c

Comments

Jagan Teki June 10, 2013, 4:01 p.m. UTC | #1
Hi,

Please use the commit header as below: just to sync with remaining
drivers in tree.

spi: arm-pl022: Add support for ARM PL022 spi controller

On Fri, Jun 7, 2013 at 1:14 PM, Armando Visconti
<armando.visconti@st.com> wrote:
> This patch adds the support for the ARM PL022 SPI controller for the standard
> variant (0x00041022), which has a 16bit wide and 8 locations deep TX/RX FIFO.
>
> Signed-off-by: Armando Visconti <armando.visconti@st.com>
> Signed-off-by: Vipin Kumar <vipin.kumar@st.com>
> Acked-by: Stefan Roese <sr@denx.de>
> ---
> v3->v4
> Just removed all warnings when running checkpatch.
> Didn't find Jagan's feedback... So, pls, let me know if we
> need to change anything else...
>
> Armando
>
>  drivers/spi/Makefile    |   1 +
>  drivers/spi/pl022_spi.c | 310 ++++++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 311 insertions(+)
>  create mode 100644 drivers/spi/pl022_spi.c
>
> diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
> index d08609e..b6443b1 100644
> --- a/drivers/spi/Makefile
> +++ b/drivers/spi/Makefile
> @@ -47,6 +47,7 @@ COBJS-$(CONFIG_MXC_SPI) += mxc_spi.o
>  COBJS-$(CONFIG_MXS_SPI) += mxs_spi.o
>  COBJS-$(CONFIG_OC_TINY_SPI) += oc_tiny_spi.o
>  COBJS-$(CONFIG_OMAP3_SPI) += omap3_spi.o
> +COBJS-$(CONFIG_PL022_SPI) += pl022_spi.o
>  COBJS-$(CONFIG_SOFT_SPI) += soft_spi.o
>  COBJS-$(CONFIG_SH_SPI) += sh_spi.o
>  COBJS-$(CONFIG_FSL_ESPI) += fsl_espi.o
> diff --git a/drivers/spi/pl022_spi.c b/drivers/spi/pl022_spi.c
> new file mode 100644
> index 0000000..8a8b9ab
> --- /dev/null
> +++ b/drivers/spi/pl022_spi.c
> @@ -0,0 +1,310 @@
> +/*
> + * (C) Copyright 2012
> + * Armando Visconti, ST Microelectronics, armando.visconti@st.com.
> + *
> + * Driver for ARM PL022 SPI Controller. Based on atmel_spi.c
> + * by Atmel Corporation.
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License as
> + * published by the Free Software Foundation; either version 2 of
> + * the License, or (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write to the Free Software
> + * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
> + * MA 02111-1307 USA
> + */
> +
> +#include <common.h>
> +#include <malloc.h>
> +#include <spi.h>
> +#include <asm/io.h>
> +#include <asm/arch/hardware.h>
> +
> +/* SSP registers mapping */
> +struct pl022 {
> +       u32     ssp_cr0;        /* 0x000 */
> +       u32     ssp_cr1;        /* 0x004 */
> +       u32     ssp_dr;         /* 0x008 */
> +       u32     ssp_sr;         /* 0x00c */
> +       u32     ssp_cpsr;       /* 0x010 */
> +       u32     ssp_imsc;       /* 0x014 */
> +       u32     ssp_ris;        /* 0x018 */
> +       u32     ssp_mis;        /* 0x01c */
> +       u32     ssp_icr;        /* 0x020 */
> +       u32     ssp_dmacr;      /* 0x024 */
> +       u8      reserved_1[0x080 - 0x028];
> +       u32     ssp_itcr;       /* 0x080 */
> +       u32     ssp_itip;       /* 0x084 */
> +       u32     ssp_itop;       /* 0x088 */
> +       u32     ssp_tdr;        /* 0x08c */
> +       u8      reserved_2[0xFE0 - 0x090];
> +       u32     ssp_pid0;       /* 0xfe0 */
> +       u32     ssp_pid1;       /* 0xfe4 */
> +       u32     ssp_pid2;       /* 0xfe8 */
> +       u32     ssp_pid3;       /* 0xfec */
> +       u32     ssp_cid0;       /* 0xff0 */
> +       u32     ssp_cid1;       /* 0xff4 */
> +       u32     ssp_cid2;       /* 0xff8 */
> +       u32     ssp_cid3;       /* 0xffc */
> +};
> +
> +/* SSP Control Register 0  - SSP_CR0 */
> +#define SSP_CR0_SPO            (0x1 << 6)
> +#define SSP_CR0_SPH            (0x1 << 7)
> +#define SSP_CR0_8BIT_MODE      (0x07)
> +#define SSP_SCR_MAX            (0xFF)
> +#define SSP_SCR_SHFT           8
> +
> +/* SSP Control Register 0  - SSP_CR1 */
> +#define SSP_CR1_MASK_SSE       (0x1 << 1)
> +
> +#define SSP_CPSR_MAX           (0xFE)
> +
> +/* SSP Status Register - SSP_SR */
> +#define SSP_SR_MASK_TFE                (0x1 << 0) /* Transmit FIFO empty */
> +#define SSP_SR_MASK_TNF                (0x1 << 1) /* Transmit FIFO not full */
> +#define SSP_SR_MASK_RNE                (0x1 << 2) /* Receive FIFO not empty */
> +#define SSP_SR_MASK_RFF                (0x1 << 3) /* Receive FIFO full */
> +#define SSP_SR_MASK_BSY                (0x1 << 4) /* Busy Flag */
> +
> +struct pl022_spi_slave {
> +       struct spi_slave slave;
> +       void *regs;
> +       unsigned int freq;
> +};
> +
> +static inline struct pl022_spi_slave *to_pl022_spi(struct spi_slave *slave)
> +{
> +       return container_of(slave, struct pl022_spi_slave, slave);
> +}
> +
------ TAG+
> +/*
> + * Following three functions should be provided by the
> + * board support package.
> + */
> +int __weak spi_cs_is_valid(unsigned int bus, unsigned int cs)
> +{
> +       return 1;
> +}
> +
> +void __weak spi_cs_activate(struct spi_slave *slave)
> +{
> +       /* do nothing */
> +}
> +
> +void __weak spi_cs_deactivate(struct spi_slave *slave)
> +{
> +       /* do nothing */
> +}
> +
> +void spi_init(void)
> +{
> +       /* do nothing */
> +}
-------------------- TAG-

Any specific reason for defining theese on to board?
Would it be possible to do the same here, as these are spi specific.

I am trying to collaborate the spi code to generic, so-that it has
some identity as other
driver did.

> +
> +/*
> + * ARM PL022 exists in different 'flavors'.
> + * This drivers currently support the standard variant (0x00041022), that has a
> + * 16bit wide and 8 locations deep TX/RX FIFO.
> + */
> +static int pl022_is_supported(struct pl022_spi_slave *ps)
> +{
> +       struct pl022 *pl022 = (struct pl022 *)ps->regs;
> +
> +       /* PL022 version is 0x00041022 */
> +       if ((readl(&pl022->ssp_pid0) == 0x22) &&
> +           (readl(&pl022->ssp_pid1) == 0x10) &&
> +           ((readl(&pl022->ssp_pid2) & 0xf) == 0x04) &&
> +           (readl(&pl022->ssp_pid3) == 0x00))

Tab space is required, for this if statement i guess, please check.

> +                       return 1;
> +
> +       return 0;
> +}
> +
> +struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
> +                       unsigned int max_hz, unsigned int mode)
> +{
> +       struct pl022_spi_slave *ps;
> +       struct pl022 *pl022;
> +       u16 scr = 1, prescaler, cr0 = 0, cpsr = 0;
> +
> +       if (!spi_cs_is_valid(bus, cs))
> +               return NULL;
> +

----- TAG+
> +       ps = malloc(sizeof(*ps));
> +       if (!ps)
> +               return NULL;
> +
> +       ps->slave.bus = bus;
> +       ps->slave.cs = cs;
----- TAG-

Code from TAG+ to TAG-, please use spi_alloc_slave()
refer any ddriver in rivers/spi/*

--
Thanks,
Jagan.

> +       ps->freq = max_hz;
> +
> +       switch (bus) {
> +       case 0:
> +               ps->regs = (void *)CONFIG_SYS_SPI_BASE;
> +               break;
> +#ifdef CONFIG_SYS_SPI_BASE1
> +       case 1:
> +               ps->regs = (void *)CONFIG_SYS_SPI_BASE1;
> +               break;
> +#endif
> +#ifdef CONFIG_SYS_SPI_BASE2
> +       case 2:
> +               ps->regs = (void *)CONFIG_SYS_SPI_BASE2;
> +               break;
> +#endif
> +#ifdef CONFIG_SYS_SPI_BASE3
> +       case 3:
> +               ps->regs = (void *)CONFIG_SYS_SPI_BASE3;
> +               break;
> +#endif
> +       default:
> +               free(ps);
> +               return NULL;
> +       }
> +
> +       pl022 = (struct pl022 *)ps->regs;
> +
> +       /* Check the PL022 version */
> +       if (!pl022_is_supported(ps)) {
> +               free(ps);
> +               return NULL;
> +       }
> +
> +       /* Set requested polarity and 8bit mode */
> +       cr0 = SSP_CR0_8BIT_MODE;
> +       cr0 |= (mode & SPI_CPHA) ? SSP_CR0_SPH : 0;
> +       cr0 |= (mode & SPI_CPOL) ? SSP_CR0_SPO : 0;
> +
> +       writel(cr0, &pl022->ssp_cr0);
> +
> +       /* Program the SSPClk frequency */
> +       prescaler = CONFIG_SYS_SPI_CLK / ps->freq;
> +
> +       if (prescaler <= 0xFF) {
> +               cpsr = prescaler;
> +       } else {
> +               for (scr = 1; scr <= SSP_SCR_MAX; scr++) {
> +                       if (!(prescaler % scr)) {
> +                               cpsr = prescaler / scr;
> +                               if (cpsr <= SSP_CPSR_MAX)
> +                                       break;
> +                       }
> +               }
> +
> +               if (scr > SSP_SCR_MAX) {
> +                       scr = SSP_SCR_MAX;
> +                       cpsr = prescaler / scr;
> +                       cpsr &= SSP_CPSR_MAX;
> +               }
> +       }
> +
> +       if (cpsr & 0x1)
> +               cpsr++;
> +
> +       writel(cpsr, &pl022->ssp_cpsr);
> +       cr0 = readl(&pl022->ssp_cr0);
> +       writel(cr0 | (scr - 1) << SSP_SCR_SHFT, &pl022->ssp_cr0);
> +
> +       return &ps->slave;
> +}
> +
> +void spi_free_slave(struct spi_slave *slave)
> +{
> +       struct pl022_spi_slave *ps = to_pl022_spi(slave);
> +
> +       free(ps);
> +}
> +
> +int spi_claim_bus(struct spi_slave *slave)
> +{
> +       struct pl022_spi_slave *ps = to_pl022_spi(slave);
> +       struct pl022 *pl022 = (struct pl022 *)ps->regs;
> +
> +       /* Enable the SPI hardware */
> +       setbits_le32(&pl022->ssp_cr1, SSP_CR1_MASK_SSE);
> +
> +       return 0;
> +}
> +
> +void spi_release_bus(struct spi_slave *slave)
> +{
> +       struct pl022_spi_slave *ps = to_pl022_spi(slave);
> +       struct pl022 *pl022 = (struct pl022 *)ps->regs;
> +
> +       /* Disable the SPI hardware */
> +       writel(0x0, &pl022->ssp_cr1);
> +}
> +
> +int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
> +               const void *dout, void *din, unsigned long flags)
> +{
> +       struct pl022_spi_slave *ps = to_pl022_spi(slave);
> +       struct pl022 *pl022 = (struct pl022 *)ps->regs;
> +       u32             len_tx = 0, len_rx = 0, len;
> +       u32             ret = 0;
> +       const u8        *txp = dout;
> +       u8              *rxp = din, value;
> +
> +       if (bitlen == 0)
> +               /* Finish any previously submitted transfers */
> +               goto out;
> +
> +       /*
> +        * TODO: The controller can do non-multiple-of-8 bit
> +        * transfers, but this driver currently doesn't support it.
> +        *
> +        * It's also not clear how such transfers are supposed to be
> +        * represented as a stream of bytes...this is a limitation of
> +        * the current SPI interface.
> +        */
> +       if (bitlen % 8) {
> +               ret = -1;
> +
> +               /* Errors always terminate an ongoing transfer */
> +               flags |= SPI_XFER_END;
> +               goto out;
> +       }
> +
> +       len = bitlen / 8;
> +
> +       if (flags & SPI_XFER_BEGIN)
> +               spi_cs_activate(slave);
> +
> +       while (len_tx < len) {
> +               if (readl(&pl022->ssp_sr) & SSP_SR_MASK_TNF) {
> +                       value = (txp != NULL) ? *txp++ : 0;
> +                       writel(value, &pl022->ssp_dr);
> +                       len_tx++;
> +               }
> +
> +               if (readl(&pl022->ssp_sr) & SSP_SR_MASK_RNE) {
> +                       value = readl(&pl022->ssp_dr);
> +                       if (rxp)
> +                               *rxp++ = value;
> +                       len_rx++;
> +               }
> +       }
> +
> +       while (len_rx < len_tx) {
> +               if (readl(&pl022->ssp_sr) & SSP_SR_MASK_RNE) {
> +                       value = readl(&pl022->ssp_dr);
> +                       if (rxp)
> +                               *rxp++ = value;
> +                       len_rx++;
> +               }
> +       }
> +
> +out:
> +       if (flags & SPI_XFER_END)
> +               spi_cs_deactivate(slave);
> +
> +       return ret;
> +}
> --
> 1.7.11.7
Armando Visconti June 12, 2013, 11:10 a.m. UTC | #2
On 06/10/2013 06:01 PM, Jagan Teki wrote:
> Hi,
>
> Please use the commit header as below: just to sync with remaining
> drivers in tree.
>
> spi: arm-pl022: Add support for ARM PL022 spi controller
>

OK,
I already did it for v5.
I'll keep it for v6 as well...

> On Fri, Jun 7, 2013 at 1:14 PM, Armando Visconti
> <armando.visconti@st.com> wrote:
>> This patch adds the support for the ARM PL022 SPI controller for the standard
>> variant (0x00041022), which has a 16bit wide and 8 locations deep TX/RX FIFO.
>>
>> Signed-off-by: Armando Visconti <armando.visconti@st.com>
>> Signed-off-by: Vipin Kumar <vipin.kumar@st.com>
>> Acked-by: Stefan Roese <sr@denx.de>
>> ---
>> v3->v4
>> Just removed all warnings when running checkpatch.
>> Didn't find Jagan's feedback... So, pls, let me know if we
>> need to change anything else...
>>
>> Armando
>>
>>   drivers/spi/Makefile    |   1 +
>>   drivers/spi/pl022_spi.c | 310 ++++++++++++++++++++++++++++++++++++++++++++++++
>>   2 files changed, 311 insertions(+)
>>   create mode 100644 drivers/spi/pl022_spi.c
>>
>> diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
>> index d08609e..b6443b1 100644
>> --- a/drivers/spi/Makefile
>> +++ b/drivers/spi/Makefile
>> @@ -47,6 +47,7 @@ COBJS-$(CONFIG_MXC_SPI) += mxc_spi.o
>>   COBJS-$(CONFIG_MXS_SPI) += mxs_spi.o
>>   COBJS-$(CONFIG_OC_TINY_SPI) += oc_tiny_spi.o
>>   COBJS-$(CONFIG_OMAP3_SPI) += omap3_spi.o
>> +COBJS-$(CONFIG_PL022_SPI) += pl022_spi.o
>>   COBJS-$(CONFIG_SOFT_SPI) += soft_spi.o
>>   COBJS-$(CONFIG_SH_SPI) += sh_spi.o
>>   COBJS-$(CONFIG_FSL_ESPI) += fsl_espi.o
>> diff --git a/drivers/spi/pl022_spi.c b/drivers/spi/pl022_spi.c
>> new file mode 100644
>> index 0000000..8a8b9ab
>> --- /dev/null
>> +++ b/drivers/spi/pl022_spi.c
>> @@ -0,0 +1,310 @@
>> +/*
>> + * (C) Copyright 2012
>> + * Armando Visconti, ST Microelectronics, armando.visconti@st.com.
>> + *
>> + * Driver for ARM PL022 SPI Controller. Based on atmel_spi.c
>> + * by Atmel Corporation.
>> + *
>> + * This program is free software; you can redistribute it and/or
>> + * modify it under the terms of the GNU General Public License as
>> + * published by the Free Software Foundation; either version 2 of
>> + * the License, or (at your option) any later version.
>> + *
>> + * This program is distributed in the hope that it will be useful,
>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>> + * GNU General Public License for more details.
>> + *
>> + * You should have received a copy of the GNU General Public License
>> + * along with this program; if not, write to the Free Software
>> + * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
>> + * MA 02111-1307 USA
>> + */
>> +
>> +#include <common.h>
>> +#include <malloc.h>
>> +#include <spi.h>
>> +#include <asm/io.h>
>> +#include <asm/arch/hardware.h>
>> +
>> +/* SSP registers mapping */
>> +struct pl022 {
>> +       u32     ssp_cr0;        /* 0x000 */
>> +       u32     ssp_cr1;        /* 0x004 */
>> +       u32     ssp_dr;         /* 0x008 */
>> +       u32     ssp_sr;         /* 0x00c */
>> +       u32     ssp_cpsr;       /* 0x010 */
>> +       u32     ssp_imsc;       /* 0x014 */
>> +       u32     ssp_ris;        /* 0x018 */
>> +       u32     ssp_mis;        /* 0x01c */
>> +       u32     ssp_icr;        /* 0x020 */
>> +       u32     ssp_dmacr;      /* 0x024 */
>> +       u8      reserved_1[0x080 - 0x028];
>> +       u32     ssp_itcr;       /* 0x080 */
>> +       u32     ssp_itip;       /* 0x084 */
>> +       u32     ssp_itop;       /* 0x088 */
>> +       u32     ssp_tdr;        /* 0x08c */
>> +       u8      reserved_2[0xFE0 - 0x090];
>> +       u32     ssp_pid0;       /* 0xfe0 */
>> +       u32     ssp_pid1;       /* 0xfe4 */
>> +       u32     ssp_pid2;       /* 0xfe8 */
>> +       u32     ssp_pid3;       /* 0xfec */
>> +       u32     ssp_cid0;       /* 0xff0 */
>> +       u32     ssp_cid1;       /* 0xff4 */
>> +       u32     ssp_cid2;       /* 0xff8 */
>> +       u32     ssp_cid3;       /* 0xffc */
>> +};
>> +
>> +/* SSP Control Register 0  - SSP_CR0 */
>> +#define SSP_CR0_SPO            (0x1 << 6)
>> +#define SSP_CR0_SPH            (0x1 << 7)
>> +#define SSP_CR0_8BIT_MODE      (0x07)
>> +#define SSP_SCR_MAX            (0xFF)
>> +#define SSP_SCR_SHFT           8
>> +
>> +/* SSP Control Register 0  - SSP_CR1 */
>> +#define SSP_CR1_MASK_SSE       (0x1 << 1)
>> +
>> +#define SSP_CPSR_MAX           (0xFE)
>> +
>> +/* SSP Status Register - SSP_SR */
>> +#define SSP_SR_MASK_TFE                (0x1 << 0) /* Transmit FIFO empty */
>> +#define SSP_SR_MASK_TNF                (0x1 << 1) /* Transmit FIFO not full */
>> +#define SSP_SR_MASK_RNE                (0x1 << 2) /* Receive FIFO not empty */
>> +#define SSP_SR_MASK_RFF                (0x1 << 3) /* Receive FIFO full */
>> +#define SSP_SR_MASK_BSY                (0x1 << 4) /* Busy Flag */
>> +
>> +struct pl022_spi_slave {
>> +       struct spi_slave slave;
>> +       void *regs;
>> +       unsigned int freq;
>> +};
>> +
>> +static inline struct pl022_spi_slave *to_pl022_spi(struct spi_slave *slave)
>> +{
>> +       return container_of(slave, struct pl022_spi_slave, slave);
>> +}
>> +
> ------ TAG+
>> +/*
>> + * Following three functions should be provided by the
>> + * board support package.
>> + */
>> +int __weak spi_cs_is_valid(unsigned int bus, unsigned int cs)
>> +{
>> +       return 1;
>> +}
>> +
>> +void __weak spi_cs_activate(struct spi_slave *slave)
>> +{
>> +       /* do nothing */
>> +}
>> +
>> +void __weak spi_cs_deactivate(struct spi_slave *slave)
>> +{
>> +       /* do nothing */
>> +}
>> +
>> +void spi_init(void)
>> +{
>> +       /* do nothing */
>> +}
> -------------------- TAG-
>
> Any specific reason for defining theese on to board?
> Would it be possible to do the same here, as these are spi specific.
>
> I am trying to collaborate the spi code to generic, so-that it has
> some identity as other
> driver did.

The pl022 SPI controller, differently from other SPI controller, does
not provide a chip select pin.
Therefore the CS must handled in a soc-specific way.
What the driver has to do is to provide dummy functions that MUST be
overwritten by soc specific ones.

If you see the pl022 linux driver does the same.


>
>> +
>> +/*
>> + * ARM PL022 exists in different 'flavors'.
>> + * This drivers currently support the standard variant (0x00041022), that has a
>> + * 16bit wide and 8 locations deep TX/RX FIFO.
>> + */
>> +static int pl022_is_supported(struct pl022_spi_slave *ps)
>> +{
>> +       struct pl022 *pl022 = (struct pl022 *)ps->regs;
>> +
>> +       /* PL022 version is 0x00041022 */
>> +       if ((readl(&pl022->ssp_pid0) == 0x22) &&
>> +           (readl(&pl022->ssp_pid1) == 0x10) &&
>> +           ((readl(&pl022->ssp_pid2) & 0xf) == 0x04) &&
>> +           (readl(&pl022->ssp_pid3) == 0x00))
>
> Tab space is required, for this if statement i guess, please check.
>

If I do then checkpatch reports a warning, saying that I need to keep
all lines of a 'if' statement aligned properly...

So, I guess that this way is more proper.


>> +                       return 1;
>> +
>> +       return 0;
>> +}
>> +
>> +struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
>> +                       unsigned int max_hz, unsigned int mode)
>> +{
>> +       struct pl022_spi_slave *ps;
>> +       struct pl022 *pl022;
>> +       u16 scr = 1, prescaler, cr0 = 0, cpsr = 0;
>> +
>> +       if (!spi_cs_is_valid(bus, cs))
>> +               return NULL;
>> +
>
> ----- TAG+
>> +       ps = malloc(sizeof(*ps));
>> +       if (!ps)
>> +               return NULL;
>> +
>> +       ps->slave.bus = bus;
>> +       ps->slave.cs = cs;
> ----- TAG-
>
> Code from TAG+ to TAG-, please use spi_alloc_slave()
> refer any ddriver in rivers/spi/*
>

ok, I'll do it!

Pls let me know if we are now fine...

Thx,
Arm
Jagan Teki June 12, 2013, 11:36 a.m. UTC | #3
On Wed, Jun 12, 2013 at 4:40 PM, Armando Visconti
<armando.visconti@st.com> wrote:
> On 06/10/2013 06:01 PM, Jagan Teki wrote:
>>
>> Hi,
>>
>> Please use the commit header as below: just to sync with remaining
>> drivers in tree.
>>
>> spi: arm-pl022: Add support for ARM PL022 spi controller
>>
>
> OK,
> I already did it for v5.
> I'll keep it for v6 as well...
>
>
>> On Fri, Jun 7, 2013 at 1:14 PM, Armando Visconti
>> <armando.visconti@st.com> wrote:
>>>
>>> This patch adds the support for the ARM PL022 SPI controller for the
>>> standard
>>> variant (0x00041022), which has a 16bit wide and 8 locations deep TX/RX
>>> FIFO.
>>>
>>> Signed-off-by: Armando Visconti <armando.visconti@st.com>
>>> Signed-off-by: Vipin Kumar <vipin.kumar@st.com>
>>> Acked-by: Stefan Roese <sr@denx.de>
>>> ---
>>> v3->v4
>>> Just removed all warnings when running checkpatch.
>>> Didn't find Jagan's feedback... So, pls, let me know if we
>>> need to change anything else...
>>>
>>> Armando
>>>
>>>   drivers/spi/Makefile    |   1 +
>>>   drivers/spi/pl022_spi.c | 310
>>> ++++++++++++++++++++++++++++++++++++++++++++++++
>>>   2 files changed, 311 insertions(+)
>>>   create mode 100644 drivers/spi/pl022_spi.c
>>>
>>> diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
>>> index d08609e..b6443b1 100644
>>> --- a/drivers/spi/Makefile
>>> +++ b/drivers/spi/Makefile
>>> @@ -47,6 +47,7 @@ COBJS-$(CONFIG_MXC_SPI) += mxc_spi.o
>>>   COBJS-$(CONFIG_MXS_SPI) += mxs_spi.o
>>>   COBJS-$(CONFIG_OC_TINY_SPI) += oc_tiny_spi.o
>>>   COBJS-$(CONFIG_OMAP3_SPI) += omap3_spi.o
>>> +COBJS-$(CONFIG_PL022_SPI) += pl022_spi.o
>>>   COBJS-$(CONFIG_SOFT_SPI) += soft_spi.o
>>>   COBJS-$(CONFIG_SH_SPI) += sh_spi.o
>>>   COBJS-$(CONFIG_FSL_ESPI) += fsl_espi.o
>>> diff --git a/drivers/spi/pl022_spi.c b/drivers/spi/pl022_spi.c
>>> new file mode 100644
>>> index 0000000..8a8b9ab
>>> --- /dev/null
>>> +++ b/drivers/spi/pl022_spi.c
>>> @@ -0,0 +1,310 @@
>>> +/*
>>> + * (C) Copyright 2012
>>> + * Armando Visconti, ST Microelectronics, armando.visconti@st.com.
>>> + *
>>> + * Driver for ARM PL022 SPI Controller. Based on atmel_spi.c
>>> + * by Atmel Corporation.
>>> + *
>>> + * This program is free software; you can redistribute it and/or
>>> + * modify it under the terms of the GNU General Public License as
>>> + * published by the Free Software Foundation; either version 2 of
>>> + * the License, or (at your option) any later version.
>>> + *
>>> + * This program is distributed in the hope that it will be useful,
>>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>>> + * GNU General Public License for more details.
>>> + *
>>> + * You should have received a copy of the GNU General Public License
>>> + * along with this program; if not, write to the Free Software
>>> + * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
>>> + * MA 02111-1307 USA
>>> + */
>>> +
>>> +#include <common.h>
>>> +#include <malloc.h>
>>> +#include <spi.h>
>>> +#include <asm/io.h>
>>> +#include <asm/arch/hardware.h>
>>> +
>>> +/* SSP registers mapping */
>>> +struct pl022 {
>>> +       u32     ssp_cr0;        /* 0x000 */
>>> +       u32     ssp_cr1;        /* 0x004 */
>>> +       u32     ssp_dr;         /* 0x008 */
>>> +       u32     ssp_sr;         /* 0x00c */
>>> +       u32     ssp_cpsr;       /* 0x010 */
>>> +       u32     ssp_imsc;       /* 0x014 */
>>> +       u32     ssp_ris;        /* 0x018 */
>>> +       u32     ssp_mis;        /* 0x01c */
>>> +       u32     ssp_icr;        /* 0x020 */
>>> +       u32     ssp_dmacr;      /* 0x024 */
>>> +       u8      reserved_1[0x080 - 0x028];
>>> +       u32     ssp_itcr;       /* 0x080 */
>>> +       u32     ssp_itip;       /* 0x084 */
>>> +       u32     ssp_itop;       /* 0x088 */
>>> +       u32     ssp_tdr;        /* 0x08c */
>>> +       u8      reserved_2[0xFE0 - 0x090];
>>> +       u32     ssp_pid0;       /* 0xfe0 */
>>> +       u32     ssp_pid1;       /* 0xfe4 */
>>> +       u32     ssp_pid2;       /* 0xfe8 */
>>> +       u32     ssp_pid3;       /* 0xfec */
>>> +       u32     ssp_cid0;       /* 0xff0 */
>>> +       u32     ssp_cid1;       /* 0xff4 */
>>> +       u32     ssp_cid2;       /* 0xff8 */
>>> +       u32     ssp_cid3;       /* 0xffc */
>>> +};
>>> +
>>> +/* SSP Control Register 0  - SSP_CR0 */
>>> +#define SSP_CR0_SPO            (0x1 << 6)
>>> +#define SSP_CR0_SPH            (0x1 << 7)
>>> +#define SSP_CR0_8BIT_MODE      (0x07)
>>> +#define SSP_SCR_MAX            (0xFF)
>>> +#define SSP_SCR_SHFT           8
>>> +
>>> +/* SSP Control Register 0  - SSP_CR1 */
>>> +#define SSP_CR1_MASK_SSE       (0x1 << 1)
>>> +
>>> +#define SSP_CPSR_MAX           (0xFE)
>>> +
>>> +/* SSP Status Register - SSP_SR */
>>> +#define SSP_SR_MASK_TFE                (0x1 << 0) /* Transmit FIFO empty
>>> */
>>> +#define SSP_SR_MASK_TNF                (0x1 << 1) /* Transmit FIFO not
>>> full */
>>> +#define SSP_SR_MASK_RNE                (0x1 << 2) /* Receive FIFO not
>>> empty */
>>> +#define SSP_SR_MASK_RFF                (0x1 << 3) /* Receive FIFO full
>>> */
>>> +#define SSP_SR_MASK_BSY                (0x1 << 4) /* Busy Flag */
>>> +
>>> +struct pl022_spi_slave {
>>> +       struct spi_slave slave;
>>> +       void *regs;
>>> +       unsigned int freq;
>>> +};
>>> +
>>> +static inline struct pl022_spi_slave *to_pl022_spi(struct spi_slave
>>> *slave)
>>> +{
>>> +       return container_of(slave, struct pl022_spi_slave, slave);
>>> +}
>>> +
>>
>> ------ TAG+
>>>
>>> +/*
>>> + * Following three functions should be provided by the
>>> + * board support package.
>>> + */
>>> +int __weak spi_cs_is_valid(unsigned int bus, unsigned int cs)
>>> +{
>>> +       return 1;
>>> +}
>>> +
>>> +void __weak spi_cs_activate(struct spi_slave *slave)
>>> +{
>>> +       /* do nothing */
>>> +}
>>> +
>>> +void __weak spi_cs_deactivate(struct spi_slave *slave)
>>> +{
>>> +       /* do nothing */
>>> +}
>>> +
>>> +void spi_init(void)
>>> +{
>>> +       /* do nothing */
>>> +}
>>
>> -------------------- TAG-
>>
>> Any specific reason for defining theese on to board?
>> Would it be possible to do the same here, as these are spi specific.
>>
>> I am trying to collaborate the spi code to generic, so-that it has
>> some identity as other
>> driver did.
>
>
> The pl022 SPI controller, differently from other SPI controller, does
> not provide a chip select pin.
> Therefore the CS must handled in a soc-specific way.
> What the driver has to do is to provide dummy functions that MUST be
> overwritten by soc specific ones.
>
> If you see the pl022 linux driver does the same.
>
>
>
>>
>>> +
>>> +/*
>>> + * ARM PL022 exists in different 'flavors'.
>>> + * This drivers currently support the standard variant (0x00041022),
>>> that has a
>>> + * 16bit wide and 8 locations deep TX/RX FIFO.
>>> + */
>>> +static int pl022_is_supported(struct pl022_spi_slave *ps)
>>> +{
>>> +       struct pl022 *pl022 = (struct pl022 *)ps->regs;
>>> +
>>> +       /* PL022 version is 0x00041022 */
>>> +       if ((readl(&pl022->ssp_pid0) == 0x22) &&
>>> +           (readl(&pl022->ssp_pid1) == 0x10) &&
>>> +           ((readl(&pl022->ssp_pid2) & 0xf) == 0x04) &&
>>> +           (readl(&pl022->ssp_pid3) == 0x00))
>>
>>
>> Tab space is required, for this if statement i guess, please check.
>>
>
> If I do then checkpatch reports a warning, saying that I need to keep
> all lines of a 'if' statement aligned properly...
>
> So, I guess that this way is more proper.

Agree, but it should be easy to interpret where should the if block
end and where should the code block starts.
I always use tab space like


+static int pl022_is_supported(struct pl022_spi_slave *ps)
+{
+       struct pl022 *pl022 = (struct pl022 *)ps->regs;
+
+       /* PL022 version is 0x00041022 */
+       if ((readl(&pl022->ssp_pid0) == 0x22) &&
+                       (readl(&pl022->ssp_pid1) == 0x10) &&
+                       ((readl(&pl022->ssp_pid2) & 0xf) == 0x04) &&
+                       (readl(&pl022->ssp_pid3) == 0x00))
+               return 1;
+
+       return 0;
+}

If you see return 1 is code block, so prior to this if ends.

--
Thanks,
Jagan.

>
>
>
>>> +                       return 1;
>>> +
>>> +       return 0;
>>> +}
>>> +
>>> +struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
>>> +                       unsigned int max_hz, unsigned int mode)
>>> +{
>>> +       struct pl022_spi_slave *ps;
>>> +       struct pl022 *pl022;
>>> +       u16 scr = 1, prescaler, cr0 = 0, cpsr = 0;
>>> +
>>> +       if (!spi_cs_is_valid(bus, cs))
>>> +               return NULL;
>>> +
>>
>>
>> ----- TAG+
>>>
>>> +       ps = malloc(sizeof(*ps));
>>> +       if (!ps)
>>> +               return NULL;
>>> +
>>> +       ps->slave.bus = bus;
>>> +       ps->slave.cs = cs;
>>
>> ----- TAG-
>>
>> Code from TAG+ to TAG-, please use spi_alloc_slave()
>> refer any ddriver in rivers/spi/*
>>
>
> ok, I'll do it!
>
> Pls let me know if we are now fine...
>
> Thx,
> Arm
>
>
Armando Visconti June 12, 2013, 12:18 p.m. UTC | #4
Hello Jagan,

>>>
>>>> +
>>>> +/*
>>>> + * ARM PL022 exists in different 'flavors'.
>>>> + * This drivers currently support the standard variant (0x00041022),
>>>> that has a
>>>> + * 16bit wide and 8 locations deep TX/RX FIFO.
>>>> + */
>>>> +static int pl022_is_supported(struct pl022_spi_slave *ps)
>>>> +{
>>>> +       struct pl022 *pl022 = (struct pl022 *)ps->regs;
>>>> +
>>>> +       /* PL022 version is 0x00041022 */
>>>> +       if ((readl(&pl022->ssp_pid0) == 0x22) &&
>>>> +           (readl(&pl022->ssp_pid1) == 0x10) &&
>>>> +           ((readl(&pl022->ssp_pid2) & 0xf) == 0x04) &&
>>>> +           (readl(&pl022->ssp_pid3) == 0x00))
>>>
>>>
>>> Tab space is required, for this if statement i guess, please check.
>>>
>>
>> If I do then checkpatch reports a warning, saying that I need to keep
>> all lines of a 'if' statement aligned properly...
>>
>> So, I guess that this way is more proper.
>
> Agree, but it should be easy to interpret where should the if block
> end and where should the code block starts.
> I always use tab space like
>
>
> +static int pl022_is_supported(struct pl022_spi_slave *ps)
> +{
> +       struct pl022 *pl022 = (struct pl022 *)ps->regs;
> +
> +       /* PL022 version is 0x00041022 */
> +       if ((readl(&pl022->ssp_pid0) == 0x22) &&
> +                       (readl(&pl022->ssp_pid1) == 0x10) &&
> +                       ((readl(&pl022->ssp_pid2) & 0xf) == 0x04) &&
> +                       (readl(&pl022->ssp_pid3) == 0x00))
> +               return 1;
> +
> +       return 0;
> +}
>
> If you see return 1 is code block, so prior to this if ends.
>

OK, I'll do it in this way even if it may generate warnings.
Give me few mins and I'll send a v6 patch!

Thx,
Arm
Jagan Teki June 12, 2013, 12:34 p.m. UTC | #5
On Wed, Jun 12, 2013 at 5:48 PM, Armando Visconti
<armando.visconti@st.com> wrote:
> Hello Jagan,
>
>
>>>>
>>>>> +
>>>>> +/*
>>>>> + * ARM PL022 exists in different 'flavors'.
>>>>> + * This drivers currently support the standard variant (0x00041022),
>>>>> that has a
>>>>> + * 16bit wide and 8 locations deep TX/RX FIFO.
>>>>> + */
>>>>> +static int pl022_is_supported(struct pl022_spi_slave *ps)
>>>>> +{
>>>>> +       struct pl022 *pl022 = (struct pl022 *)ps->regs;
>>>>> +
>>>>> +       /* PL022 version is 0x00041022 */
>>>>> +       if ((readl(&pl022->ssp_pid0) == 0x22) &&
>>>>> +           (readl(&pl022->ssp_pid1) == 0x10) &&
>>>>> +           ((readl(&pl022->ssp_pid2) & 0xf) == 0x04) &&
>>>>> +           (readl(&pl022->ssp_pid3) == 0x00))
>>>>
>>>>
>>>>
>>>> Tab space is required, for this if statement i guess, please check.
>>>>
>>>
>>> If I do then checkpatch reports a warning, saying that I need to keep
>>> all lines of a 'if' statement aligned properly...
>>>
>>> So, I guess that this way is more proper.
>>
>>
>> Agree, but it should be easy to interpret where should the if block
>> end and where should the code block starts.
>> I always use tab space like
>>
>>
>> +static int pl022_is_supported(struct pl022_spi_slave *ps)
>> +{
>> +       struct pl022 *pl022 = (struct pl022 *)ps->regs;
>> +
>> +       /* PL022 version is 0x00041022 */
>> +       if ((readl(&pl022->ssp_pid0) == 0x22) &&
>> +                       (readl(&pl022->ssp_pid1) == 0x10) &&
>> +                       ((readl(&pl022->ssp_pid2) & 0xf) == 0x04) &&
>> +                       (readl(&pl022->ssp_pid3) == 0x00))
>> +               return 1;
>> +
>> +       return 0;
>> +}
>>
>> If you see return 1 is code block, so prior to this if ends.
>>
>
> OK, I'll do it in this way even if it may generate warnings.
> Give me few mins and I'll send a v6 patch!
>
> Thx,
> Arm
>
>
> --
> -- "Every step appears to be the unavoidable consequence of the
> -- preceding one." (A. Einstein)
> --
> Armando Visconti                  Mobile: (+39) 346 8879146
> Senior SW Engineer                Fax:    (+39) 02 93519290
> CPG                               Work:   (+39) 02 93519683
> Computer System Division          e-mail: armando.visconti@st.com
> ST Microelectronics               TINA:   051  4683
>
>

Please use the commit header as "spi: pl022_spi: "
as you haven't use the same on v5 i guess, please check.

--
Thanks,
Jagan.
Armando Visconti June 12, 2013, 12:39 p.m. UTC | #6
>
> Please use the commit header as "spi: pl022_spi: "
> as you haven't use the same on v5 i guess, please check.
>

OK, Jagan,
I'll do it!

Armando
diff mbox

Patch

diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index d08609e..b6443b1 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -47,6 +47,7 @@  COBJS-$(CONFIG_MXC_SPI) += mxc_spi.o
 COBJS-$(CONFIG_MXS_SPI) += mxs_spi.o
 COBJS-$(CONFIG_OC_TINY_SPI) += oc_tiny_spi.o
 COBJS-$(CONFIG_OMAP3_SPI) += omap3_spi.o
+COBJS-$(CONFIG_PL022_SPI) += pl022_spi.o
 COBJS-$(CONFIG_SOFT_SPI) += soft_spi.o
 COBJS-$(CONFIG_SH_SPI) += sh_spi.o
 COBJS-$(CONFIG_FSL_ESPI) += fsl_espi.o
diff --git a/drivers/spi/pl022_spi.c b/drivers/spi/pl022_spi.c
new file mode 100644
index 0000000..8a8b9ab
--- /dev/null
+++ b/drivers/spi/pl022_spi.c
@@ -0,0 +1,310 @@ 
+/*
+ * (C) Copyright 2012
+ * Armando Visconti, ST Microelectronics, armando.visconti@st.com.
+ *
+ * Driver for ARM PL022 SPI Controller. Based on atmel_spi.c
+ * by Atmel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <common.h>
+#include <malloc.h>
+#include <spi.h>
+#include <asm/io.h>
+#include <asm/arch/hardware.h>
+
+/* SSP registers mapping */
+struct pl022 {
+	u32	ssp_cr0;	/* 0x000 */
+	u32	ssp_cr1;	/* 0x004 */
+	u32	ssp_dr;		/* 0x008 */
+	u32	ssp_sr;		/* 0x00c */
+	u32	ssp_cpsr;	/* 0x010 */
+	u32	ssp_imsc;	/* 0x014 */
+	u32	ssp_ris;	/* 0x018 */
+	u32	ssp_mis;	/* 0x01c */
+	u32	ssp_icr;	/* 0x020 */
+	u32	ssp_dmacr;	/* 0x024 */
+	u8	reserved_1[0x080 - 0x028];
+	u32	ssp_itcr;	/* 0x080 */
+	u32	ssp_itip;	/* 0x084 */
+	u32	ssp_itop;	/* 0x088 */
+	u32	ssp_tdr;	/* 0x08c */
+	u8	reserved_2[0xFE0 - 0x090];
+	u32	ssp_pid0;	/* 0xfe0 */
+	u32	ssp_pid1;	/* 0xfe4 */
+	u32	ssp_pid2;	/* 0xfe8 */
+	u32	ssp_pid3;	/* 0xfec */
+	u32	ssp_cid0;	/* 0xff0 */
+	u32	ssp_cid1;	/* 0xff4 */
+	u32	ssp_cid2;	/* 0xff8 */
+	u32	ssp_cid3;	/* 0xffc */
+};
+
+/* SSP Control Register 0  - SSP_CR0 */
+#define SSP_CR0_SPO		(0x1 << 6)
+#define SSP_CR0_SPH		(0x1 << 7)
+#define SSP_CR0_8BIT_MODE	(0x07)
+#define SSP_SCR_MAX		(0xFF)
+#define SSP_SCR_SHFT		8
+
+/* SSP Control Register 0  - SSP_CR1 */
+#define SSP_CR1_MASK_SSE	(0x1 << 1)
+
+#define SSP_CPSR_MAX		(0xFE)
+
+/* SSP Status Register - SSP_SR */
+#define SSP_SR_MASK_TFE		(0x1 << 0) /* Transmit FIFO empty */
+#define SSP_SR_MASK_TNF		(0x1 << 1) /* Transmit FIFO not full */
+#define SSP_SR_MASK_RNE		(0x1 << 2) /* Receive FIFO not empty */
+#define SSP_SR_MASK_RFF		(0x1 << 3) /* Receive FIFO full */
+#define SSP_SR_MASK_BSY		(0x1 << 4) /* Busy Flag */
+
+struct pl022_spi_slave {
+	struct spi_slave slave;
+	void *regs;
+	unsigned int freq;
+};
+
+static inline struct pl022_spi_slave *to_pl022_spi(struct spi_slave *slave)
+{
+	return container_of(slave, struct pl022_spi_slave, slave);
+}
+
+/*
+ * Following three functions should be provided by the
+ * board support package.
+ */
+int __weak spi_cs_is_valid(unsigned int bus, unsigned int cs)
+{
+	return 1;
+}
+
+void __weak spi_cs_activate(struct spi_slave *slave)
+{
+	/* do nothing */
+}
+
+void __weak spi_cs_deactivate(struct spi_slave *slave)
+{
+	/* do nothing */
+}
+
+void spi_init(void)
+{
+	/* do nothing */
+}
+
+/*
+ * ARM PL022 exists in different 'flavors'.
+ * This drivers currently support the standard variant (0x00041022), that has a
+ * 16bit wide and 8 locations deep TX/RX FIFO.
+ */
+static int pl022_is_supported(struct pl022_spi_slave *ps)
+{
+	struct pl022 *pl022 = (struct pl022 *)ps->regs;
+
+	/* PL022 version is 0x00041022 */
+	if ((readl(&pl022->ssp_pid0) == 0x22) &&
+	    (readl(&pl022->ssp_pid1) == 0x10) &&
+	    ((readl(&pl022->ssp_pid2) & 0xf) == 0x04) &&
+	    (readl(&pl022->ssp_pid3) == 0x00))
+			return 1;
+
+	return 0;
+}
+
+struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
+			unsigned int max_hz, unsigned int mode)
+{
+	struct pl022_spi_slave *ps;
+	struct pl022 *pl022;
+	u16 scr = 1, prescaler, cr0 = 0, cpsr = 0;
+
+	if (!spi_cs_is_valid(bus, cs))
+		return NULL;
+
+	ps = malloc(sizeof(*ps));
+	if (!ps)
+		return NULL;
+
+	ps->slave.bus = bus;
+	ps->slave.cs = cs;
+	ps->freq = max_hz;
+
+	switch (bus) {
+	case 0:
+		ps->regs = (void *)CONFIG_SYS_SPI_BASE;
+		break;
+#ifdef CONFIG_SYS_SPI_BASE1
+	case 1:
+		ps->regs = (void *)CONFIG_SYS_SPI_BASE1;
+		break;
+#endif
+#ifdef CONFIG_SYS_SPI_BASE2
+	case 2:
+		ps->regs = (void *)CONFIG_SYS_SPI_BASE2;
+		break;
+#endif
+#ifdef CONFIG_SYS_SPI_BASE3
+	case 3:
+		ps->regs = (void *)CONFIG_SYS_SPI_BASE3;
+		break;
+#endif
+	default:
+		free(ps);
+		return NULL;
+	}
+
+	pl022 = (struct pl022 *)ps->regs;
+
+	/* Check the PL022 version */
+	if (!pl022_is_supported(ps)) {
+		free(ps);
+		return NULL;
+	}
+
+	/* Set requested polarity and 8bit mode */
+	cr0 = SSP_CR0_8BIT_MODE;
+	cr0 |= (mode & SPI_CPHA) ? SSP_CR0_SPH : 0;
+	cr0 |= (mode & SPI_CPOL) ? SSP_CR0_SPO : 0;
+
+	writel(cr0, &pl022->ssp_cr0);
+
+	/* Program the SSPClk frequency */
+	prescaler = CONFIG_SYS_SPI_CLK / ps->freq;
+
+	if (prescaler <= 0xFF) {
+		cpsr = prescaler;
+	} else {
+		for (scr = 1; scr <= SSP_SCR_MAX; scr++) {
+			if (!(prescaler % scr)) {
+				cpsr = prescaler / scr;
+				if (cpsr <= SSP_CPSR_MAX)
+					break;
+			}
+		}
+
+		if (scr > SSP_SCR_MAX) {
+			scr = SSP_SCR_MAX;
+			cpsr = prescaler / scr;
+			cpsr &= SSP_CPSR_MAX;
+		}
+	}
+
+	if (cpsr & 0x1)
+		cpsr++;
+
+	writel(cpsr, &pl022->ssp_cpsr);
+	cr0 = readl(&pl022->ssp_cr0);
+	writel(cr0 | (scr - 1) << SSP_SCR_SHFT, &pl022->ssp_cr0);
+
+	return &ps->slave;
+}
+
+void spi_free_slave(struct spi_slave *slave)
+{
+	struct pl022_spi_slave *ps = to_pl022_spi(slave);
+
+	free(ps);
+}
+
+int spi_claim_bus(struct spi_slave *slave)
+{
+	struct pl022_spi_slave *ps = to_pl022_spi(slave);
+	struct pl022 *pl022 = (struct pl022 *)ps->regs;
+
+	/* Enable the SPI hardware */
+	setbits_le32(&pl022->ssp_cr1, SSP_CR1_MASK_SSE);
+
+	return 0;
+}
+
+void spi_release_bus(struct spi_slave *slave)
+{
+	struct pl022_spi_slave *ps = to_pl022_spi(slave);
+	struct pl022 *pl022 = (struct pl022 *)ps->regs;
+
+	/* Disable the SPI hardware */
+	writel(0x0, &pl022->ssp_cr1);
+}
+
+int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
+		const void *dout, void *din, unsigned long flags)
+{
+	struct pl022_spi_slave *ps = to_pl022_spi(slave);
+	struct pl022 *pl022 = (struct pl022 *)ps->regs;
+	u32		len_tx = 0, len_rx = 0, len;
+	u32		ret = 0;
+	const u8	*txp = dout;
+	u8		*rxp = din, value;
+
+	if (bitlen == 0)
+		/* Finish any previously submitted transfers */
+		goto out;
+
+	/*
+	 * TODO: The controller can do non-multiple-of-8 bit
+	 * transfers, but this driver currently doesn't support it.
+	 *
+	 * It's also not clear how such transfers are supposed to be
+	 * represented as a stream of bytes...this is a limitation of
+	 * the current SPI interface.
+	 */
+	if (bitlen % 8) {
+		ret = -1;
+
+		/* Errors always terminate an ongoing transfer */
+		flags |= SPI_XFER_END;
+		goto out;
+	}
+
+	len = bitlen / 8;
+
+	if (flags & SPI_XFER_BEGIN)
+		spi_cs_activate(slave);
+
+	while (len_tx < len) {
+		if (readl(&pl022->ssp_sr) & SSP_SR_MASK_TNF) {
+			value = (txp != NULL) ? *txp++ : 0;
+			writel(value, &pl022->ssp_dr);
+			len_tx++;
+		}
+
+		if (readl(&pl022->ssp_sr) & SSP_SR_MASK_RNE) {
+			value = readl(&pl022->ssp_dr);
+			if (rxp)
+				*rxp++ = value;
+			len_rx++;
+		}
+	}
+
+	while (len_rx < len_tx) {
+		if (readl(&pl022->ssp_sr) & SSP_SR_MASK_RNE) {
+			value = readl(&pl022->ssp_dr);
+			if (rxp)
+				*rxp++ = value;
+			len_rx++;
+		}
+	}
+
+out:
+	if (flags & SPI_XFER_END)
+		spi_cs_deactivate(slave);
+
+	return ret;
+}