diff options
Diffstat (limited to 'drivers/spi')
| -rw-r--r-- | drivers/spi/designware_spi.c | 51 |
1 files changed, 50 insertions, 1 deletions
diff --git a/drivers/spi/designware_spi.c b/drivers/spi/designware_spi.c index b51242c862..06f777461e 100644 --- a/drivers/spi/designware_spi.c +++ b/drivers/spi/designware_spi.c @@ -10,6 +10,7 @@ * SPDX-License-Identifier: GPL-2.0 */ +#include <asm-generic/gpio.h> #include <common.h> #include <clk.h> #include <dm.h> @@ -98,6 +99,8 @@ struct dw_spi_priv { struct clk clk; unsigned long bus_clk_rate; + struct gpio_desc cs_gpio; /* External chip-select gpio */ + int bits_per_word; u8 cs; /* chip select pin */ u8 tmode; /* TR/TO/RO/EEPROM */ @@ -131,6 +134,32 @@ static inline void dw_writew(struct dw_spi_priv *priv, u32 offset, u16 val) __raw_writew(val, priv->regs + offset); } +static int request_gpio_cs(struct udevice *bus) +{ +#if defined(CONFIG_DM_GPIO) && !defined(CONFIG_SPL_BUILD) + struct dw_spi_priv *priv = dev_get_priv(bus); + int ret; + + /* External chip select gpio line is optional */ + ret = gpio_request_by_name(bus, "cs-gpio", 0, &priv->cs_gpio, 0); + if (ret == -ENOENT) + return 0; + + if (ret < 0) { + printf("Error: %d: Can't get %s gpio!\n", ret, bus->name); + return ret; + } + + if (dm_gpio_is_valid(&priv->cs_gpio)) { + dm_gpio_set_dir_flags(&priv->cs_gpio, + GPIOD_IS_OUT | GPIOD_IS_OUT_ACTIVE); + } + + debug("%s: used external gpio for CS management\n", __func__); +#endif + return 0; +} + static int dw_spi_ofdata_to_platdata(struct udevice *bus) { struct dw_spi_platdata *plat = bus->platdata; @@ -145,7 +174,7 @@ static int dw_spi_ofdata_to_platdata(struct udevice *bus) debug("%s: regs=%p max-frequency=%d\n", __func__, plat->regs, plat->frequency); - return 0; + return request_gpio_cs(bus); } static inline void spi_enable_chip(struct dw_spi_priv *priv, int enable) @@ -316,6 +345,18 @@ static int poll_transfer(struct dw_spi_priv *priv) return 0; } +static void external_cs_manage(struct udevice *dev, bool on) +{ +#if defined(CONFIG_DM_GPIO) && !defined(CONFIG_SPL_BUILD) + struct dw_spi_priv *priv = dev_get_priv(dev->parent); + + if (!dm_gpio_is_valid(&priv->cs_gpio)) + return; + + dm_gpio_set_value(&priv->cs_gpio, on ? 1 : 0); +#endif +} + static int dw_spi_xfer(struct udevice *dev, unsigned int bitlen, const void *dout, void *din, unsigned long flags) { @@ -334,6 +375,10 @@ static int dw_spi_xfer(struct udevice *dev, unsigned int bitlen, return -1; } + /* Start the transaction if necessary. */ + if (flags & SPI_XFER_BEGIN) + external_cs_manage(dev, false); + cr0 = (priv->bits_per_word - 1) | (priv->type << SPI_FRF_OFFSET) | (priv->mode << SPI_MODE_OFFSET) | (priv->tmode << SPI_TMOD_OFFSET); @@ -395,6 +440,10 @@ static int dw_spi_xfer(struct udevice *dev, unsigned int bitlen, ret = -ETIMEDOUT; } + /* Stop the transaction if necessary */ + if (flags & SPI_XFER_END) + external_cs_manage(dev, true); + return ret; } |