diff options
author | Xu Yilun <yilun.xu@intel.com> | 2020-06-19 09:43:40 +0800 |
---|---|---|
committer | Mark Brown <broonie@kernel.org> | 2020-06-19 12:56:05 +0100 |
commit | 3820061d38156d88443d32a9a6c701d281234746 (patch) | |
tree | 6a0503d3487a2f7b7b092fd96ffb61cbcbe04454 /drivers/spi/spi-altera.c | |
parent | 3c6519736eefebafdf8c82d46f64b214403b5260 (diff) | |
download | linux-3820061d38156d88443d32a9a6c701d281234746.tar.gz |
spi: altera: support indirect access to the registers
This patch adds support for indirect access to the registers via parent
regmap.
The use case is, the spi master is a sub device of a Multifunction
device, which is connected to host by some indirect bus. To support this
device type, a new platform_device_id is introduced, and the driver tries
to get parent regmap for register accessing like many MFD sub device
drivers do.
Signed-off-by: Xu Yilun <yilun.xu@intel.com>
Signed-off-by: Matthew Gerlach <matthew.gerlach@linux.intel.com>
Signed-off-by: Wu Hao <hao.wu@intel.com>
Signed-off-by: Russ Weight <russell.h.weight@intel.com>
Reviewed-by: Tom Rix <trix@redhat.com>
Link: https://lore.kernel.org/r/1592531021-11412-3-git-send-email-yilun.xu@intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/spi/spi-altera.c')
-rw-r--r-- | drivers/spi/spi-altera.c | 62 |
1 files changed, 47 insertions, 15 deletions
diff --git a/drivers/spi/spi-altera.c b/drivers/spi/spi-altera.c index b215bdfb77fd..4f7717f16def 100644 --- a/drivers/spi/spi-altera.c +++ b/drivers/spi/spi-altera.c @@ -43,6 +43,11 @@ #define ALTERA_SPI_MAX_CS 32 +enum altera_spi_type { + ALTERA_SPI_TYPE_UNKNOWN, + ALTERA_SPI_TYPE_SUBDEV, +}; + struct altera_spi { int irq; int len; @@ -55,6 +60,7 @@ struct altera_spi { unsigned char *rx; struct regmap *regmap; + u32 regoff; struct device *dev; }; @@ -70,7 +76,7 @@ static int altr_spi_writel(struct altera_spi *hw, unsigned int reg, { int ret; - ret = regmap_write(hw->regmap, reg, val); + ret = regmap_write(hw->regmap, hw->regoff + reg, val); if (ret) dev_err(hw->dev, "fail to write reg 0x%x val 0x%x: %d\n", reg, val, ret); @@ -83,7 +89,7 @@ static int altr_spi_readl(struct altera_spi *hw, unsigned int reg, { int ret; - ret = regmap_read(hw->regmap, reg, val); + ret = regmap_read(hw->regmap, hw->regoff + reg, val); if (ret) dev_err(hw->dev, "fail to read reg 0x%x: %d\n", reg, ret); @@ -225,10 +231,11 @@ static irqreturn_t altera_spi_irq(int irq, void *dev) static int altera_spi_probe(struct platform_device *pdev) { + const struct platform_device_id *platid = platform_get_device_id(pdev); struct altera_spi_platform_data *pdata = dev_get_platdata(&pdev->dev); + enum altera_spi_type type = ALTERA_SPI_TYPE_UNKNOWN; struct altera_spi *hw; struct spi_master *master; - void __iomem *res; int err = -ENODEV; u32 val; u16 i; @@ -264,19 +271,38 @@ static int altera_spi_probe(struct platform_device *pdev) hw = spi_master_get_devdata(master); hw->dev = &pdev->dev; + if (platid) + type = platid->driver_data; + /* find and map our resources */ - res = devm_platform_ioremap_resource(pdev, 0); - if (IS_ERR(res)) { - err = PTR_ERR(res); - goto exit; - } + if (type == ALTERA_SPI_TYPE_SUBDEV) { + struct resource *regoff; - hw->regmap = devm_regmap_init_mmio(&pdev->dev, res, - &spi_altera_config); - if (IS_ERR(hw->regmap)) { - dev_err(&pdev->dev, "regmap mmio init failed\n"); - err = PTR_ERR(hw->regmap); - goto exit; + hw->regmap = dev_get_regmap(pdev->dev.parent, NULL); + if (!hw->regmap) { + dev_err(&pdev->dev, "get regmap failed\n"); + goto exit; + } + + regoff = platform_get_resource(pdev, IORESOURCE_REG, 0); + if (regoff) + hw->regoff = regoff->start; + } else { + void __iomem *res; + + res = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(res)) { + err = PTR_ERR(res); + goto exit; + } + + hw->regmap = devm_regmap_init_mmio(&pdev->dev, res, + &spi_altera_config); + if (IS_ERR(hw->regmap)) { + dev_err(&pdev->dev, "regmap mmio init failed\n"); + err = PTR_ERR(hw->regmap); + goto exit; + } } /* program defaults into the registers */ @@ -308,7 +334,7 @@ static int altera_spi_probe(struct platform_device *pdev) } } - dev_info(&pdev->dev, "base %p, irq %d\n", res, hw->irq); + dev_info(&pdev->dev, "regoff %u, irq %d\n", hw->regoff, hw->irq); return 0; exit: @@ -325,6 +351,11 @@ static const struct of_device_id altera_spi_match[] = { MODULE_DEVICE_TABLE(of, altera_spi_match); #endif /* CONFIG_OF */ +static const struct platform_device_id altera_spi_ids[] = { + { "subdev_spi_altera", ALTERA_SPI_TYPE_SUBDEV }, + { } +}; + static struct platform_driver altera_spi_driver = { .probe = altera_spi_probe, .driver = { @@ -332,6 +363,7 @@ static struct platform_driver altera_spi_driver = { .pm = NULL, .of_match_table = of_match_ptr(altera_spi_match), }, + .id_table = altera_spi_ids, }; module_platform_driver(altera_spi_driver); |