On 01/12/2020 21:12, Sowjanya Komatineni wrote:
> Tegra SoC has a Quad SPI controller starting from Tegra210.
>
> This patch adds support for Tegra210 QSPI controller.
>
> Signed-off-by: Sowjanya Komatineni <skomatin...@nvidia.com>
> ---
> drivers/spi/Kconfig | 9 +
> drivers/spi/Makefile | 1 +
> drivers/spi/qspi-tegra.c | 1418
> ++++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 1428 insertions(+)
> create mode 100644 drivers/spi/qspi-tegra.c
>
> diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
> index 3fd16b7..1a021e8 100644
> --- a/drivers/spi/Kconfig
> +++ b/drivers/spi/Kconfig
> @@ -844,6 +844,15 @@ config SPI_MXS
> help
> SPI driver for Freescale MXS devices.
>
> +config QSPI_TEGRA
> + tristate "Nvidia Tegra QSPI Controller"
> + depends on (ARCH_TEGRA && TEGRA20_APB_DMA) || COMPILE_TEST
I assume that the dependency on the APBDMA is for Tegra210. Does it work
on Tegra210 without the DMA? I am wondering if this is a dependency?
> +static void tegra_qspi_deinit_dma_param(struct tegra_qspi_data *tqspi,
> + bool dma_to_memory)
> +{
> + u32 *dma_buf;
> + dma_addr_t dma_phys;
> + struct dma_chan *dma_chan;
> +
> + if (dma_to_memory) {
> + dma_buf = tqspi->rx_dma_buf;
> + dma_chan = tqspi->rx_dma_chan;
> + dma_phys = tqspi->rx_dma_phys;
> + tqspi->rx_dma_chan = NULL;
> + tqspi->rx_dma_buf = NULL;
> + } else {
> + dma_buf = tqspi->tx_dma_buf;
> + dma_chan = tqspi->tx_dma_chan;
> + dma_phys = tqspi->tx_dma_phys;
> + tqspi->tx_dma_buf = NULL;
> + tqspi->tx_dma_chan = NULL;
> + }
> + if (!dma_chan)
> + return;
The above seemed odd to me at first, but I guess if a device does not
support DMA yet, then this will be NULL. However, would it be clearer to
just ...
if (!tqspi->use_dma)
return;
You could also do this right at the beginning of the function.
> +static struct tegra_qspi_client_data
> + *tegra_qspi_parse_cdata_dt(struct spi_device *spi)
> +{
> + struct tegra_qspi_client_data *cdata;
> + struct device_node *slave_np;
> +
> + slave_np = spi->dev.of_node;
> + if (!slave_np) {
This test should not be necessary as we only support device-tree.
> + dev_dbg(&spi->dev, "device node not found\n");
> + return NULL;
> + }
> +
> + cdata = kzalloc(sizeof(*cdata), GFP_KERNEL);
> + if (!cdata)
> + return NULL;
> +
> + of_property_read_u32(slave_np, "nvidia,tx-clk-tap-delay",
> + &cdata->tx_clk_tap_delay);
> + of_property_read_u32(slave_np, "nvidia,rx-clk-tap-delay",
> + &cdata->rx_clk_tap_delay);
> + return cdata;
> +}
> +
> +static void tegra_qspi_cleanup(struct spi_device *spi)
> +{
> + struct tegra_qspi_client_data *cdata = spi->controller_data;
> +
> + spi->controller_data = NULL;
> + if (spi->dev.of_node)
> + kfree(cdata);
> +}
> +
> +static int tegra_qspi_setup(struct spi_device *spi)
> +{
> + struct tegra_qspi_data *tqspi = spi_master_get_devdata(spi->master);
> + struct tegra_qspi_client_data *cdata = spi->controller_data;
> + u32 tx_tap = 0, rx_tap = 0;
> + u32 val;
> + unsigned long flags;
> + int ret;
> +
> + dev_dbg(&spi->dev, "setup %d bpw, %scpol, %scpha, %dHz\n",
> + spi->bits_per_word,
> + spi->mode & SPI_CPOL ? "" : "~",
> + spi->mode & SPI_CPHA ? "" : "~",
> + spi->max_speed_hz);
> +
> + if (!cdata) {
> + cdata = tegra_qspi_parse_cdata_dt(spi);
> + spi->controller_data = cdata;
> + }
> +
> + ret = pm_runtime_get_sync(tqspi->dev);
> + if (ret < 0) {
> + dev_err(tqspi->dev, "runtime resume failed: %d\n", ret);
> + if (cdata)
> + tegra_qspi_cleanup(spi);
> + return ret;
> + }
Does it simplify the code to do the pm_runtime_get_sync() before the
parsing of the cdata?
> +static int tegra_qspi_probe(struct platform_device *pdev)
> +{
> + struct spi_master *master;
> + struct tegra_qspi_data *tqspi;
> + struct resource *r;
> + int ret, qspi_irq;
> + int bus_num;
> +
> + master = spi_alloc_master(&pdev->dev, sizeof(*tqspi));
> + if (!master) {
> + dev_err(&pdev->dev, "master allocation failed\n");
> + return -ENOMEM;
> + }
> +
> + platform_set_drvdata(pdev, master);
> + tqspi = spi_master_get_devdata(master);
> +
> + if (of_property_read_u32(pdev->dev.of_node, "spi-max-frequency",
> + &master->max_speed_hz))
> + master->max_speed_hz = QSPI_MAX_SPEED;
> +
> + /* the spi->mode bits understood by this driver: */
> + master->mode_bits = SPI_MODE_0 | SPI_MODE_3 | SPI_CS_HIGH |
> + SPI_TX_DUAL | SPI_RX_DUAL | SPI_TX_QUAD |
> + SPI_RX_QUAD;
> + master->bits_per_word_mask = SPI_BPW_MASK(32) | SPI_BPW_MASK(16) |
> + SPI_BPW_MASK(8);
> + master->setup = tegra_qspi_setup;
> + master->cleanup = tegra_qspi_cleanup;
> + master->transfer_one_message = tegra_qspi_transfer_one_message;
> + master->num_chipselect = 1;
> + master->auto_runtime_pm = true;
> + bus_num = of_alias_get_id(pdev->dev.of_node, "spi");
> + if (bus_num >= 0)
> + master->bus_num = bus_num;
> +
> + tqspi->master = master;
> + tqspi->dev = &pdev->dev;
> + spin_lock_init(&tqspi->lock);
> +
> + r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + tqspi->base = devm_ioremap_resource(&pdev->dev, r);
> + if (IS_ERR(tqspi->base)) {
> + ret = PTR_ERR(tqspi->base);
> + goto exit_free_master;
> + }
> +
> + tqspi->phys = r->start;
> + qspi_irq = platform_get_irq(pdev, 0);
> + tqspi->irq = qspi_irq;
> +
> + tqspi->clk = devm_clk_get(&pdev->dev, "qspi");
> + if (IS_ERR(tqspi->clk)) {
> + ret = PTR_ERR(tqspi->clk);
> + dev_err(&pdev->dev, "failed to get clock: %d\n", ret);
> + goto exit_free_master;
> + }
> +
> + tqspi->rst = devm_reset_control_get_exclusive(&pdev->dev, "qspi");
> + if (IS_ERR(tqspi->rst)) {
> + ret = PTR_ERR(tqspi->rst);
> + dev_err(&pdev->dev, "failed to get reset control: %d\n", ret);
> + goto exit_free_master;
> + }
> +
> + tqspi->max_buf_size = QSPI_FIFO_DEPTH << 2;
> + tqspi->dma_buf_size = DEFAULT_QSPI_DMA_BUF_LEN;
> +
> + ret = tegra_qspi_init_dma_param(tqspi, true);
> + if (ret < 0)
> + goto exit_free_master;
> + ret = tegra_qspi_init_dma_param(tqspi, false);
> + if (ret < 0)
> + goto exit_rx_dma_free;
I would be tempted to combine the init for the TX and RX into a single
function. Then we can have a single function to deinit.
> +
> + if (tqspi->use_dma)
> + tqspi->max_buf_size = tqspi->dma_buf_size;
> +
> + init_completion(&tqspi->tx_dma_complete);
> + init_completion(&tqspi->rx_dma_complete);
> +
Unnecessary blank line.
> + init_completion(&tqspi->xfer_completion);
> +
> + pm_runtime_enable(&pdev->dev);
> + if (!pm_runtime_enabled(&pdev->dev)) {
RPM is always enabled for Tegra and so if this fails we should just fail.
> + ret = tegra_qspi_runtime_resume(&pdev->dev);
> + if (ret)
> + goto exit_pm_disable;
> + }
> +
> + ret = pm_runtime_get_sync(&pdev->dev);
> + if (ret < 0) {
> + dev_err(&pdev->dev, "runtime resume failed: %d\n", ret);
> + pm_runtime_put_noidle(&pdev->dev)
You can use pm_runtime_resume_and_get() now and then you don't need to
call pm_runtime_put_noidle() on failure.
> + goto exit_pm_disable;
> + }
> +
> + reset_control_assert(tqspi->rst);
> + udelay(2);
> + reset_control_deassert(tqspi->rst);
> + tqspi->def_command1_reg = QSPI_M_S | QSPI_CS_SW_HW | QSPI_CS_SW_VAL;
> + tegra_qspi_writel(tqspi, tqspi->def_command1_reg, QSPI_COMMAND1);
> + tqspi->spi_cs_timing1 = tegra_qspi_readl(tqspi, QSPI_CS_TIMING1);
> + tqspi->spi_cs_timing2 = tegra_qspi_readl(tqspi, QSPI_CS_TIMING2);
> + tqspi->def_command2_reg = tegra_qspi_readl(tqspi, QSPI_COMMAND2);
> +
> + pm_runtime_put(&pdev->dev);
> +
> + ret = request_threaded_irq(tqspi->irq, tegra_qspi_isr,
> + tegra_qspi_isr_thread, IRQF_ONESHOT,
> + dev_name(&pdev->dev), tqspi);
> + if (ret < 0) {
> + dev_err(&pdev->dev,
> + "failed to request IRQ#%u: %d\n", tqspi->irq, ret);
> + goto exit_pm_disable;
> + }
> +
> + master->dev.of_node = pdev->dev.of_node;
> + ret = devm_spi_register_master(&pdev->dev, master);
> + if (ret < 0) {
> + dev_err(&pdev->dev, "failed to register master: %d\n", ret);
> + goto exit_free_irq;
> + }
> + return ret;
return 0
> +static int tegra_qspi_runtime_resume(struct device *dev)
> +{
> + struct spi_master *master = dev_get_drvdata(dev);
> + struct tegra_qspi_data *tqspi = spi_master_get_devdata(master);
> + int ret;
> +
> + ret = clk_prepare_enable(tqspi->clk);
> + if (ret < 0) {
> + dev_err(tqspi->dev, "clk_prepare failed: %d\n", ret);
> + return ret;
> + }
> + return 0;
Always just 'return ret' here.
Cheers
Jon
--
nvpublic
