[U-Boot] [PATCH] support spi gpio driver by control gpio bitbang

[Minkyu Kang]

Dear Donghwa Lee,

2010/9/1 Donghwa Lee <yiffie9819 at gmail.com>:
>  This patch adds basic support for spi mode 0~3 by control gpio bitbang.
> It uses several gpio pin and emulates spi chipselect signal, clock signal
> and sda signal as if spi controller generate spi signal.
>
>
> Signed-off-by: Donghwa Lee <dh09.lee at samsung.com <http://lists.denx.de/mailman/listinfo/u-boot>>

Please fix your email address.

>
>
> ---
> drivers/spi/spi_gpio.c | 153 ++++++++++++++++++++++++++++++++++++++++++++++++
> include/spi.h | 27 +++++++++
> 2 files changed, 180 insertions(+), 0 deletions(-)
> create mode 100644 drivers/spi/spi_gpio.c

Your patch is line wrapped and the tabs are stripped out.
Please resubmit.
And then, people would review your patch.

>
> diff --git a/drivers/spi/spi_gpio.c b/drivers/spi/spi_gpio.c
> new file mode 100644
> index 0000000..cce809e
> --- /dev/null
> +++ b/drivers/spi/spi_gpio.c
> @@ -0,0 +1,153 @@
> +/*
> + * Copyright (C) 2010 Samsung Electronics

Please insert the name of author

> + * spi_gpio.c - SPI master driver using generic bitbanged GPIO
> + *
> + * 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
> + */
> +
> +

please remove this space

> +#include <common.h>
> +#include <asm/arch/gpio.h>
> +#include <spi.h>
> +
> +static void spi_gpio_set_sck(struct spi_platform_data *spi, int is_on)
> +{
> + gpio_set_value(spi->clk_bank, spi->clk_num, is_on);
> +}
> +
> +static void spi_gpio_set_mosi(struct spi_platform_data *spi, int is_on)
> +{
> + gpio_set_value(spi->si_bank, spi->si_num, is_on);
> +}
> +
> +static void spi_gpio_chipselect(struct spi_platform_data *spi,
> + int cpol)
> +{
> + gpio_set_value(spi->cs_bank, spi->cs_num,
> + !spi->cs_active);
> +
> + /* set initial clock polarity */
> + if (cpol)
> + spi_gpio_set_sck(spi, spi->mode & SPI_CPOL);
> +
> + /* SPI is normally active-low */
> + gpio_set_value(spi->cs_bank, spi->cs_num,
> + spi->cs_active);
> +}
> +
> +static void
> +spi_gpio_tx_cpha0(struct spi_platform_data *spi,
> + unsigned int nsecs, unsigned int cpol,
> + unsigned int word, unsigned int bits)
> +{
> + int i;
> + unsigned int data;
> +
> + data = (word << spi->word_len) + bits;
> +
> + spi_gpio_chipselect(spi, cpol);
> +
> + /* clock starts at inactive polarity */
> + for (i = spi->word_len; i >= 0; i--) {
> +
> + /* data high or low */
> + if ((data >> i) & 0x1)
> + spi_gpio_set_mosi(spi, 1);
> + else
> + spi_gpio_set_mosi(spi, 0);
> +
> + udelay(nsecs);
> +
> + spi_gpio_set_sck(spi, !cpol);
> + udelay(nsecs);
> +
> + spi_gpio_set_sck(spi, cpol);
> + }
> +}
> +
> +static void
> +spi_gpio_tx_cpha1(struct spi_platform_data *spi,
> + unsigned int nsecs, unsigned int cpol,
> + unsigned int word, unsigned int bits)
> +{
> + int i;
> + unsigned int data;
> +
> + data = (word << spi->word_len) + bits;
> +
> + spi_gpio_chipselect(spi, cpol);
> +
> + /* clock starts at inactive polarity */
> + for (i = spi->word_len; i >= 0; i--) {
> +
please remove this space

> + /* setup MSB (to slave) on leading edge */
> + spi_gpio_set_sck(spi, !cpol);
> +
> + /* data high or low */
> + if ((data >> i) & 0x1)
> + spi_gpio_set_mosi(spi, 1);
> + else
> + spi_gpio_set_mosi(spi, 0);
> +
> + udelay(nsecs);
> +
> + spi_gpio_set_sck(spi, cpol);
> + udelay(nsecs);
> + }
> +}
> +
> +static void spi_gpio_tx_word_mode0(struct spi_platform_data *spi,
> + unsigned int nsecs, unsigned int word, unsigned int bits)
> +{
> + return spi_gpio_tx_cpha0(spi, nsecs, 0, word, bits);
> +}
> +
> +static void spi_gpio_tx_word_mode1(struct spi_platform_data *spi,
> + unsigned int nsecs, unsigned int word, unsigned int bits)
> +{
> + return spi_gpio_tx_cpha1(spi, nsecs, 0, word, bits);
> +}
> +
> +static void spi_gpio_tx_word_mode2(struct spi_platform_data *spi,
> + unsigned int nsecs, unsigned int word, unsigned int bits)
> +{
> + return spi_gpio_tx_cpha0(spi, nsecs, 1, word, bits);
> +}
> +
> +static void spi_gpio_tx_word_mode3(struct spi_platform_data *spi,
> + unsigned int nsecs, unsigned int word, unsigned int bits)
> +{
> + return spi_gpio_tx_cpha1(spi, nsecs, 1, word, bits);
> +}
> +
> +void spi_gpio_write(struct spi_platform_data *spi,
> + unsigned int address, unsigned int command)
> +{
> + switch (spi->mode) {
> + case SPI_MODE_0:
> + spi_gpio_tx_word_mode0(spi,
> + 1, address, command);
> + case SPI_MODE_1:
> + spi_gpio_tx_word_mode1(spi,
> + 1, address, command);
> + case SPI_MODE_2:
> + spi_gpio_tx_word_mode2(spi,
> + 1, address, command);
> + case SPI_MODE_3:
> + spi_gpio_tx_word_mode3(spi,
> + 1, address, command);
> + }
> +}
> diff --git a/include/spi.h b/include/spi.h
> index 320e50e..ef3f94d 100644
> --- a/include/spi.h
> +++ b/include/spi.h
> @@ -62,6 +62,33 @@ struct spi_slave {
> unsigned int cs;
> };
>
> +#define COMMAND_ONLY 0xFE
> +#define DATA_ONLY 0xFF
> +#define ACTIVE_LOW 0
> +#define ACTIVE_HIGH 1
> +
please remove this space
> +
> +struct spi_platform_data {
> + struct s5p_gpio_bank *cs_bank;
> + struct s5p_gpio_bank *clk_bank;
> + struct s5p_gpio_bank *si_bank;
> + struct s5p_gpio_bank *so_bank;

Is it S5P SoC specific?
It will be occur compiler errors at other SoCs.

> +
> + unsigned int cs_num;
> + unsigned int clk_num;
> + unsigned int si_num;
> + unsigned int so_num;
> +
> + unsigned int mode;
> + unsigned int cs_active;
> + unsigned int word_len;
> +
> + unsigned int set_rev;
> +};
> +
> +void spi_gpio_write(struct spi_platform_data *spi,
> + unsigned int address, unsigned int command);
> +
> /*-----------------------------------------------------------------------
> * Initialization, must be called once on start up.
> *
> --
> 1.6.0.4
>
>
> _______________________________________________
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>
>


Thanks
Minkyu Kang
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