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Date: Fri, 8 May 2020 15:13:35 +0200
From: Emil Renner Berthing <emil.renner.berthing@...il.com>
To: Chris Ruehl <chris.ruehl@...ys.com.hk>
Cc: Jack Lo <jack.lo@...ys.com.hk>, Heiko Stuebner <heiko@...ech.de>,
Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
linux-spi@...r.kernel.org,
"open list:ARM/Rockchip SoC..." <linux-rockchip@...ts.infradead.org>,
Mark Brown <broonie@...nel.org>,
linux-arm-kernel <linux-arm-kernel@...ts.infradead.org>
Subject: Re: [PATCH v0 1/1] spi: spi-rockchip: add support for spi slave_mode
Hi Chris,
On Fri, 8 May 2020 at 10:47, Chris Ruehl <chris.ruehl@...ys.com.hk> wrote:
>
> This patch aim to add spi slave mode support to the rockchip driver.
> Fix the wrong usage of num_cs set fix to ROCKCHIP_SPI_MAX_CS_NUM,
> instead use max_native_cs flag to set the limit of native chip-select.
> Enable use_gpio_descriptors to have cs_gpiod for gpio based chip-selects.
>
> Signed-off-by: Chris Ruehl <chris.ruehl@...ys.com.hk>
> ---
> drivers/spi/spi-rockchip.c | 46 +++++++++++++++++++++++++++++++++-----
> 1 file changed, 41 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/spi/spi-rockchip.c b/drivers/spi/spi-rockchip.c
> index 70ef63e0b6b8..9c1ff52c0f85 100644
> --- a/drivers/spi/spi-rockchip.c
> +++ b/drivers/spi/spi-rockchip.c
> @@ -183,6 +183,9 @@ struct rockchip_spi {
> u8 rsd;
>
> bool cs_asserted[ROCKCHIP_SPI_MAX_CS_NUM];
> +
> + bool slave_mode;
> + bool slave_abort;
> };
>
> static inline void spi_enable_chip(struct rockchip_spi *rs, bool enable)
> @@ -359,7 +362,7 @@ static void rockchip_spi_dma_rxcb(void *data)
> struct rockchip_spi *rs = spi_master_get_devdata(master);
> int state = atomic_fetch_andnot(RXDMA, &rs->state);
>
> - if (state & TXDMA)
> + if (state & TXDMA && !rs->slave_abort)
> return;
>
> spi_enable_chip(rs, false);
> @@ -372,7 +375,7 @@ static void rockchip_spi_dma_txcb(void *data)
> struct rockchip_spi *rs = spi_master_get_devdata(master);
> int state = atomic_fetch_andnot(TXDMA, &rs->state);
>
> - if (state & RXDMA)
> + if (state & RXDMA && !rs->slave_abort)
> return;
>
> /* Wait until the FIFO data completely. */
> @@ -466,6 +469,10 @@ static void rockchip_spi_config(struct rockchip_spi *rs,
> u32 cr1;
> u32 dmacr = 0;
>
> + if (rs->slavemode)
> + cr0 |= CR0_OPM_SLAVE << CR0_OPM_OFFSET;
> + rs->slave_abort = false;
> +
> cr0 |= rs->rsd << CR0_RSD_OFFSET;
> cr0 |= (spi->mode & 0x3U) << CR0_SCPH_OFFSET;
> if (spi->mode & SPI_LSB_FIRST)
> @@ -535,6 +542,16 @@ static size_t rockchip_spi_max_transfer_size(struct spi_device *spi)
> return ROCKCHIP_SPI_MAX_TRANLEN;
> }
>
> +static int rockchip_spi_slave_abort(struct spi_master *master)
> +{
> + struct rockchip_spi *rs = spi_master_get_devdata(master);
> +
> + rs->slave_abort = true;
> + complete(master);
> +
> + return 0;
> +}
> +
> static int rockchip_spi_transfer_one(
> struct spi_master *master,
> struct spi_device *spi,
> @@ -589,14 +606,25 @@ static int rockchip_spi_probe(struct platform_device *pdev)
> struct spi_master *master;
> struct resource *mem;
> u32 rsd_nsecs;
> + bool slave_mode;
> + u32 num_cs = 1;
> +
> + slave_mode = of_property_read_bool(np, "spi-slave");
> +
> + if (slave_mode)
> + master = spi_alloc_slave(&pdev->dev,
> + sizeof(struct rockchip_spi));
> + else
> + master = spi_alloc_master(&pdev->dev,
> + sizeof(struct rockchip_spi));
>
> - master = spi_alloc_master(&pdev->dev, sizeof(struct rockchip_spi));
> if (!master)
> return -ENOMEM;
>
> platform_set_drvdata(pdev, master);
>
> rs = spi_master_get_devdata(master);
> + rs->slave_mode = slave_mode;
This entry doesn't seem to be read from any of your code, and even it
it was, the same information is available in master->slave, so I don't
see why you need it in the rockchip_spi struct.
Also spi_master is just #defined to spi_controller in spi.h, so maybe
consider changing all 'struct spi_master *master' to 'struct
spi_controller *ctrl' now that the driver supports both modes.
>
> /* Get basic io resource and map it */
> mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> @@ -676,7 +704,16 @@ static int rockchip_spi_probe(struct platform_device *pdev)
> master->auto_runtime_pm = true;
> master->bus_num = pdev->id;
> master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LOOP | SPI_LSB_FIRST;
> - master->num_chipselect = ROCKCHIP_SPI_MAX_CS_NUM;
> + if (slave_mode) {
> + master->mode_bits |= SPI_NO_CS;
> + master->slave_abort = rockchip_spi_slave_abort;
> + } else {
> + of_property_read_u32(np, "num-cs", &num_cs);
> + master->num_chipselect = num_cs;
If you do something like this you won't need the temporary num_cs variable:
if (of_property_read_u32(np, "num-cs", &master->num_chipselect))
master->num_chipselect = 1;
Also it seems like you're changing the default from
ROCKCHIP_SPI_MAX_CS_NUM to 1 if there is no num-cs property. Did you
check that all boards either have the num-cs property defined or only
needs num_chipselect = 1?
> + master->use_gpio_descriptors = true;
> + master->max_native_cs = ROCKCHIP_SPI_MAX_CS_NUM;
> + master->flags = SPI_MASTER_GPIO_SS;
> + }
> master->dev.of_node = pdev->dev.of_node;
> master->bits_per_word_mask = SPI_BPW_MASK(16) | SPI_BPW_MASK(8) | SPI_BPW_MASK(4);
> master->min_speed_hz = rs->freq / BAUDR_SCKDV_MAX;
> @@ -686,7 +723,6 @@ static int rockchip_spi_probe(struct platform_device *pdev)
> master->transfer_one = rockchip_spi_transfer_one;
> master->max_transfer_size = rockchip_spi_max_transfer_size;
> master->handle_err = rockchip_spi_handle_err;
> - master->flags = SPI_MASTER_GPIO_SS;
>
> master->dma_tx = dma_request_chan(rs->dev, "tx");
> if (IS_ERR(master->dma_tx)) {
> --
> 2.20.1
>
>
> _______________________________________________
> Linux-rockchip mailing list
> Linux-rockchip@...ts.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-rockchip
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