Re: [PATCH 2/2] spi: spi-geni-qcom: Add SPI SLAVE mode support for GENI based QuPv3

From: Praveen Talari <quic_ptalari@quicinc.com>
To: Konrad Dybcio <konrad.dybcio@linaro.org>, <agross@kernel.org>,
	<andersson@kernel.org>, <broonie@kernel.org>,
	<linux-arm-msm@vger.kernel.org>, <linux-spi@vger.kernel.org>,
	<linux-kernel@vger.kernel.org>
Cc: <quic_msavaliy@quicinc.com>, <quic_vtanuku@quicinc.com>,
	<quic_vnivarth@quicinc.com>, <quic_arandive@quicinc.com>
Subject: Re: [PATCH 2/2] spi: spi-geni-qcom: Add SPI SLAVE mode support for GENI based QuPv3
Date: Thu, 15 Jun 2023 12:35:11 +0530	[thread overview]
Message-ID: <66f3bedf-5181-09da-c945-5cc8b8dda381@quicinc.com> (raw)
In-Reply-To: <d39df510-c0d0-97c2-4a35-e28829ddd761@linaro.org>

Hi

Thank you for review.

On 6/13/2023 5:57 PM, Konrad Dybcio wrote:
>
> On 13.06.2023 08:52, Praveen Talari wrote:
>> Add SPI SLAVE mode support for GENI based QuPv3.
>>
> Copying the commit title in the commit message is a bit lackluster for
> adding new functionality.
Modified commit message
>> Signed-off-by: Praveen Talari <quic_ptalari@quicinc.com>
>> ---
>>   drivers/spi/spi-geni-qcom.c | 55 +++++++++++++++++++++++++++++++++----
>>   1 file changed, 49 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/spi/spi-geni-qcom.c b/drivers/spi/spi-geni-qcom.c
>> index 206cc04bb1ed..2e3ae29e79e0 100644
>> --- a/drivers/spi/spi-geni-qcom.c
>> +++ b/drivers/spi/spi-geni-qcom.c
>> @@ -12,6 +12,7 @@
>>   #include <linux/platform_device.h>
>>   #include <linux/pm_opp.h>
>>   #include <linux/pm_runtime.h>
>> +#include <linux/property.h>
>>   #include <linux/soc/qcom/geni-se.h>
>>   #include <linux/spi/spi.h>
>>   #include <linux/spinlock.h>
>> @@ -52,6 +53,9 @@
>>   #define SPI_CS_CLK_DELAY_MSK		GENMASK(19, 10)
>>   #define SPI_CS_CLK_DELAY_SHFT		10
>>   
>> +#define SE_SPI_SLAVE_EN				(0x2BC)
>> +#define SPI_SLAVE_EN				BIT(0)
>> +
>>   /* M_CMD OP codes for SPI */
>>   #define SPI_TX_ONLY		1
>>   #define SPI_RX_ONLY		2
>> @@ -99,6 +103,24 @@ struct spi_geni_master {
>>   	int cur_xfer_mode;
>>   };
>>   
>> +static struct spi_master *get_spi_master(struct device *dev)
>> +{
>> +	struct platform_device *pdev = to_platform_device(dev);
>> +	struct spi_master *spi = platform_get_drvdata(pdev);
>> +
>> +	return spi;
>> +}
>> +
>> +static void spi_slv_setup(struct spi_geni_master *mas)
>> +{
>> +	struct geni_se *se = &mas->se;
>> +
>> +	writel(SPI_SLAVE_EN, se->base + SE_SPI_SLAVE_EN);
>> +	writel(GENI_IO_MUX_0_EN, se->base + GENI_OUTPUT_CTRL);
>> +	writel(START_TRIGGER, se->base + SE_GENI_CFG_SEQ_START);
>> +	dev_info(mas->dev, "spi slave setup done\n");
> dev_dbg
changed to dev_dbg
>
>> +}
>> +
>>   static int get_spi_clk_cfg(unsigned int speed_hz,
>>   			struct spi_geni_master *mas,
>>   			unsigned int *clk_idx,
>> @@ -140,12 +162,18 @@ static void handle_se_timeout(struct spi_master *spi,
>>   	const struct spi_transfer *xfer;
>>   
>>   	spin_lock_irq(&mas->lock);
>> -	reinit_completion(&mas->cancel_done);
>>   	if (mas->cur_xfer_mode == GENI_SE_FIFO)
>>   		writel(0, se->base + SE_GENI_TX_WATERMARK_REG);
>>   
>>   	xfer = mas->cur_xfer;
>>   	mas->cur_xfer = NULL;
>> +
>> +	if (spi->slave) {
>> +		spin_unlock_irq(&mas->lock);
>> +		goto unmap_if_dma;
>> +	}
>> +
>> +	reinit_completion(&mas->cancel_done);
> Moving reiniting cancel_done after possibly writing the register
> for both mas/slv cases sounds like a separate change - is it
> necessary?
there will be a chance of double reinit for slave because of goto 
statement. Hence moved to down.
>
>>   	geni_se_cancel_m_cmd(se);
>>   	spin_unlock_irq(&mas->lock);
>>   
>> @@ -541,6 +569,8 @@ static bool geni_can_dma(struct spi_controller *ctlr,
>>   
>>   	if (mas->cur_xfer_mode == GENI_GPI_DMA)
>>   		return true;
>> +	if (ctlr->slave)
>> +		return true;
> Regardless of the xfer mode?
we always operates spi slave in dma mode and added code comments
>
>>   
>>   	len = get_xfer_len_in_words(xfer, mas);
>>   	fifo_size = mas->tx_fifo_depth * mas->fifo_width_bits / mas->cur_bits_per_word;
>> @@ -619,6 +649,7 @@ static void spi_geni_release_dma_chan(struct spi_geni_master *mas)
>>   
>>   static int spi_geni_init(struct spi_geni_master *mas)
>>   {
>> +	struct spi_master *spi = get_spi_master(mas->dev);
>>   	struct geni_se *se = &mas->se;
>>   	unsigned int proto, major, minor, ver;
>>   	u32 spi_tx_cfg, fifo_disable;
>> @@ -627,7 +658,14 @@ static int spi_geni_init(struct spi_geni_master *mas)
>>   	pm_runtime_get_sync(mas->dev);
>>   
>>   	proto = geni_se_read_proto(se);
>> -	if (proto != GENI_SE_SPI) {
>> +
>> +	if (spi->slave) {
>> +		if (proto != GENI_SE_SPI_SLAVE) {
>> +			dev_err(mas->dev, "Invalid proto %d\n", proto);
>> +			goto out_pm;
>> +		}
>> +		spi_slv_setup(mas);
>> +	} else if (proto != GENI_SE_SPI) {
>>   		dev_err(mas->dev, "Invalid proto %d\n", proto);
>>   		goto out_pm;
>>   	}
>> @@ -677,9 +715,11 @@ static int spi_geni_init(struct spi_geni_master *mas)
>>   	}
>>   
>>   	/* We always control CS manually */
>> -	spi_tx_cfg = readl(se->base + SE_SPI_TRANS_CFG);
>> -	spi_tx_cfg &= ~CS_TOGGLE;
>> -	writel(spi_tx_cfg, se->base + SE_SPI_TRANS_CFG);
>> +	if (!spi->slave) {
>> +		spi_tx_cfg = readl(se->base + SE_SPI_TRANS_CFG);
>> +		spi_tx_cfg &= ~CS_TOGGLE;
>> +		writel(spi_tx_cfg, se->base + SE_SPI_TRANS_CFG);
>> +	}
>>   
>>   out_pm:
>>   	pm_runtime_put(mas->dev);
>> @@ -1072,6 +1112,9 @@ static int spi_geni_probe(struct platform_device *pdev)
>>   	pm_runtime_set_autosuspend_delay(&pdev->dev, 250);
>>   	pm_runtime_enable(dev);
>>   
>> +	if (device_property_read_bool(&pdev->dev, "qcom,slv-ctrl"))
>> +		spi->slave = true;
> Missing dt-bindings
Added dt-binding file
>
> Konrad
>> +
>>   	ret = geni_icc_get(&mas->se, NULL);
>>   	if (ret)
>>   		goto spi_geni_probe_runtime_disable;
>> @@ -1092,7 +1135,7 @@ static int spi_geni_probe(struct platform_device *pdev)
>>   	 * for dma (gsi) mode, the gsi will set cs based on params passed in
>>   	 * TRE
>>   	 */
>> -	if (mas->cur_xfer_mode == GENI_SE_FIFO)
>> +	if (!spi->slave && mas->cur_xfer_mode == GENI_SE_FIFO)`
>>   		spi->set_cs = spi_geni_set_cs;
>>   
>>   	ret = request_irq(mas->irq, geni_spi_isr, 0, dev_name(dev), spi);