[U-Boot] [PATCH] spi: mxc_spi: support driver model

Lothar Waßmann LW at KARO-electronics.de
Tue Aug 8 10:20:28 UTC 2017


Hi,

On Tue,  8 Aug 2017 18:00:01 +0800 Peng Fan wrote:
> Add driver model support for mxc spi driver.
> Most functions are restructured to be reused by DM and non-DM.
> Tested on mx6slevk/mx6qsabresd board.
> 
> Signed-off-by: Peng Fan <peng.fan at nxp.com>
> Cc: Jagan Teki <jagan at openedev.com>
> cc: Stefano Babic <sbabic at denx.de>
> ---
>  drivers/spi/mxc_spi.c | 183 +++++++++++++++++++++++++++++++++++++++++---------
>  1 file changed, 150 insertions(+), 33 deletions(-)
> 
> diff --git a/drivers/spi/mxc_spi.c b/drivers/spi/mxc_spi.c
> index e1562c3..44fed94 100644
> --- a/drivers/spi/mxc_spi.c
> +++ b/drivers/spi/mxc_spi.c
> @@ -5,6 +5,7 @@
>   */
>  
>  #include <common.h>
> +#include <dm.h>
>  #include <malloc.h>
>  #include <spi.h>
>  #include <linux/errno.h>
> @@ -14,6 +15,8 @@
>  #include <asm/arch/clock.h>
>  #include <asm/mach-imx/spi.h>
>  
> +DECLARE_GLOBAL_DATA_PTR;
> +
>  #ifdef CONFIG_MX27
>  /* i.MX27 has a completely wrong register layout and register definitions in the
>   * datasheet, the correct one is in the Freescale's Linux driver */
> @@ -22,10 +25,6 @@
>  "See linux mxc_spi driver from Freescale for details."
>  #endif
>  
> -static unsigned long spi_bases[] = {
> -	MXC_SPI_BASE_ADDRESSES
> -};
> -
>  __weak int board_spi_cs_gpio(unsigned bus, unsigned cs)
>  {
>  	return -1;
> @@ -51,6 +50,7 @@ struct mxc_spi_slave {
>  	int		ss_pol;
>  	unsigned int	max_hz;
>  	unsigned int	mode;
> +	struct gpio_desc ss;
>  };
>  
>  static inline struct mxc_spi_slave *to_mxc_spi_slave(struct spi_slave *slave)
> @@ -58,19 +58,24 @@ static inline struct mxc_spi_slave *to_mxc_spi_slave(struct spi_slave *slave)
>  	return container_of(slave, struct mxc_spi_slave, slave);
>  }
>  
> -void spi_cs_activate(struct spi_slave *slave)
> +static void mxc_spi_cs_activate(struct mxc_spi_slave *mxcs)
>  {
> -	struct mxc_spi_slave *mxcs = to_mxc_spi_slave(slave);
> -	if (mxcs->gpio > 0)
> -		gpio_set_value(mxcs->gpio, mxcs->ss_pol);
> +	if (CONFIG_IS_ENABLED(DM_SPI)) {
>
Shouldn't this be DM_GPIO rather than DM_SPI?

> +		dm_gpio_set_value(&mxcs->ss, mxcs->ss_pol);
> +	} else {
> +		if (mxcs->gpio > 0)
> +			gpio_set_value(mxcs->gpio, mxcs->ss_pol);
> +	}
>  }
>  
> -void spi_cs_deactivate(struct spi_slave *slave)
> +static void mxc_spi_cs_deactivate(struct mxc_spi_slave *mxcs)
>  {
> -	struct mxc_spi_slave *mxcs = to_mxc_spi_slave(slave);
> -	if (mxcs->gpio > 0)
> -		gpio_set_value(mxcs->gpio,
> -			      !(mxcs->ss_pol));
> +	if (CONFIG_IS_ENABLED(DM_SPI)) {
dto.

> +		dm_gpio_set_value(&mxcs->ss, !(mxcs->ss_pol));
> +	} else {
> +		if (mxcs->gpio > 0)
> +			gpio_set_value(mxcs->gpio, !(mxcs->ss_pol));
> +	}
>  }
>  
>  u32 get_cspi_div(u32 div)
> @@ -211,10 +216,9 @@ static s32 spi_cfg_mxc(struct mxc_spi_slave *mxcs, unsigned int cs)
>  }
>  #endif
>  
> -int spi_xchg_single(struct spi_slave *slave, unsigned int bitlen,
> +int spi_xchg_single(struct mxc_spi_slave *mxcs, unsigned int bitlen,
>  	const u8 *dout, u8 *din, unsigned long flags)
>  {
> -	struct mxc_spi_slave *mxcs = to_mxc_spi_slave(slave);
>  	int nbytes = DIV_ROUND_UP(bitlen, 8);
>  	u32 data, cnt, i;
>  	struct cspi_regs *regs = (struct cspi_regs *)mxcs->base;
> @@ -327,8 +331,9 @@ int spi_xchg_single(struct spi_slave *slave, unsigned int bitlen,
>  
>  }
>  
> -int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
> -		void *din, unsigned long flags)
> +static int mxc_spi_xfer_internal(struct mxc_spi_slave *mxcs,
> +				 unsigned int bitlen, const void *dout,
> +				 void *din, unsigned long flags)
>  {
>  	int n_bytes = DIV_ROUND_UP(bitlen, 8);
>  	int n_bits;
> @@ -337,11 +342,11 @@ int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
>  	u8 *p_outbuf = (u8 *)dout;
>  	u8 *p_inbuf = (u8 *)din;
>  
> -	if (!slave)
> -		return -1;
> +	if (!mxcs)
> +		return -EINVAL;
>  
>  	if (flags & SPI_XFER_BEGIN)
> -		spi_cs_activate(slave);
> +		mxc_spi_cs_activate(mxcs);
>  
>  	while (n_bytes > 0) {
>  		if (n_bytes < MAX_SPI_BYTES)
> @@ -351,7 +356,7 @@ int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
>  
>  		n_bits = blk_size * 8;
>  
> -		ret = spi_xchg_single(slave, n_bits, p_outbuf, p_inbuf, 0);
> +		ret = spi_xchg_single(mxcs, n_bits, p_outbuf, p_inbuf, 0);
>  
>  		if (ret)
>  			return ret;
> @@ -363,12 +368,39 @@ int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
>  	}
>  
>  	if (flags & SPI_XFER_END) {
> -		spi_cs_deactivate(slave);
> +		mxc_spi_cs_deactivate(mxcs);
> +	}
> +
> +	return 0;
> +}
> +
> +static int mxc_spi_claim_bus_internal(struct mxc_spi_slave *mxcs, int cs)
> +{
> +	struct cspi_regs *regs = (struct cspi_regs *)mxcs->base;
> +	int ret;
> +
> +	reg_write(&regs->rxdata, 1);
> +	udelay(1);
> +	ret = spi_cfg_mxc(mxcs, 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);
>  
>  	return 0;
>  }
>  
> +#ifndef CONFIG_DM_SPI
> +int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
> +		void *din, unsigned long flags)
> +{
> +	struct mxc_spi_slave *mxcs = to_mxc_spi_slave(slave);
> +
> +	return mxc_spi_xfer_internal(mxcs, bitlen, dout, din, flags);
> +}
> +
>  void spi_init(void)
>  {
>  }
> @@ -390,6 +422,7 @@ static int setup_cs_gpio(struct mxc_spi_slave *mxcs,
>  	if (mxcs->gpio == -1)
>  		return 0;
>  
> +	gpio_request(mxcs->gpio, "spi-cs");
>  	ret = gpio_direction_output(mxcs->gpio, !(mxcs->ss_pol));
>  	if (ret) {
>  		printf("mxc_spi: cannot setup gpio %d\n", mxcs->gpio);
> @@ -399,6 +432,10 @@ static int setup_cs_gpio(struct mxc_spi_slave *mxcs,
>  	return 0;
>  }
>  
> +static unsigned long spi_bases[] = {
> +	MXC_SPI_BASE_ADDRESSES
> +};
> +
>  struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
>  			unsigned int max_hz, unsigned int mode)
>  {
> @@ -443,24 +480,104 @@ 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);
> -	ret = spi_cfg_mxc(mxcs, slave->cs);
> +	return mxc_spi_claim_bus_internal(mxcs, slave->cs);
> +}
> +
> +void spi_release_bus(struct spi_slave *slave)
> +{
> +	/* TODO: Shut the controller down */
> +}
> +#else
> +
> +static int mxc_spi_probe(struct udevice *bus)
> +{
> +	struct mxc_spi_slave *plat = bus->platdata;
> +	struct mxc_spi_slave *mxcs = dev_get_platdata(bus);
> +	int node = dev_of_offset(bus);
> +	const void *blob = gd->fdt_blob;
> +	int ret;
> +
> +	if (gpio_request_by_name(bus, "cs-gpios", 0, &plat->ss,
> +				 GPIOD_IS_OUT)) {
> +		dev_err(bus, "No cs-gpios property\n");
> +		return -EINVAL;
> +	}
> +
> +	plat->base = dev_get_addr(bus);
> +	if (plat->base == FDT_ADDR_T_NONE)
> +		return -EINVAL;
>
IMO -ENODEV is more appropriate here.

> +	ret = dm_gpio_set_value(&plat->ss, !(mxcs->ss_pol));
>
No conditional on CONFIG_IS_ENABLED() here?

>  	if (ret) {
> -		printf("mxc_spi: cannot setup SPI controller\n");
> -		return ret;
> +		dev_err(bus, "Setting cs error\n");
> +		return -EBUSY;
>
dm_gpio_set_value() returned an appropriate error code which should be
passed to the caller rather than inventing a new error code.



Lothar Waßmann


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