Merge tag 'spi-v5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi

Pull spi updates from Mark Brown:
 "The big update this time around is some excellent work from David
  Jander who went through the fast path and really eliminated overheads,
  meaning that we are seeing a huge reduction in the time spent between
  transfers for single threaded clients.

  Benchmarking has been coming out at about a halving of overhead which
  is clearly visible in system level usage that stresses SPI like some
  CAN and IIO applications, especially with small transfers. Thanks to
  David for taking the time to drill down into this and push the work
  upstream.

  Otherwise there's been a bunch of new device support and the usual
  updates.

   - Optimisation of the fast path, particularly around the number and
     types of locking operations, from David Jander.

   - Support for Arbel NPCM845, HP GXP, Intel Meteor Lake and Thunder
     Bay, MediaTek MT8188 and MT8365, Microchip FPGAs, nVidia Tegra 241
     and Samsung Exynos Auto v9 and 4210"

* tag 'spi-v5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi: (97 commits)
  MAINTAINERS: add spi support to GXP
  spi: dt-bindings: add documentation for hpe,gxp-spifi
  spi: spi-gxp: Add support for HPE GXP SoCs
  spi: a3700: support BE for AC5 SPI driver
  spi/panel: dt-bindings: drop CPHA and CPOL from common properties
  spi: bcm2835: enable shared interrupt support
  spi: dt-bindings: spi-controller: correct example indentation
  spi: dt-bindings: qcom,spi-geni-qcom: allow three interconnects
  spi: npcm-fiu: Add NPCM8XX support
  dt-binding: spi: Add npcm845 compatible to npcm-fiu document
  spi: npcm-fiu: Modify direct read dummy configuration
  spi: atmel: remove #ifdef CONFIG_{PM, SLEEP}
  spi: dt-bindings: Add compatible for MediaTek MT8188
  spi: dt-bindings: mediatek,spi-mtk-nor: Update bindings for nor flash
  spi: dt-bindings: atmel,at91rm9200-spi: convert to json-schema
  spi: tegra20-slink: fix UAF in tegra_slink_remove()
  spi: Fix simplification of devm_spi_register_controller
  spi: microchip-core: switch to use dev_err_probe()
  spi: microchip-core: switch to use devm_spi_alloc_master()
  spi: microchip-core: fix UAF in mchp_corespi_remove()
  ...

1 files changed, 39 insertions, 36 deletions

diff --git a/drivers/spi/spi-ti-qspi.c b/drivers/spi/spi-ti-qspi.c
index b5b65d882d7a..60086869bcae 100644
--- a/drivers/spi/spi-ti-qspi.c
+++ b/drivers/spi/spi-ti-qspi.c
@@ -57,7 +57,6 @@ struct ti_qspi {
 	void			*rx_bb_addr;
 	struct dma_chan		*rx_chan;
 
-	u32 spi_max_frequency;
 	u32 cmd;
 	u32 dc;
 
@@ -140,37 +139,19 @@ static inline void ti_qspi_write(struct ti_qspi *qspi,
 static int ti_qspi_setup(struct spi_device *spi)
 {
 	struct ti_qspi	*qspi = spi_master_get_devdata(spi->master);
-	struct ti_qspi_regs *ctx_reg = &qspi->ctx_reg;
-	int clk_div = 0, ret;
-	u32 clk_ctrl_reg, clk_rate, clk_mask;
+	int ret;
 
 	if (spi->master->busy) {
 		dev_dbg(qspi->dev, "master busy doing other transfers\n");
 		return -EBUSY;
 	}
 
-	if (!qspi->spi_max_frequency) {
+	if (!qspi->master->max_speed_hz) {
 		dev_err(qspi->dev, "spi max frequency not defined\n");
 		return -EINVAL;
 	}
 
-	clk_rate = clk_get_rate(qspi->fclk);
-
-	clk_div = DIV_ROUND_UP(clk_rate, qspi->spi_max_frequency) - 1;
-
-	if (clk_div < 0) {
-		dev_dbg(qspi->dev, "clock divider < 0, using /1 divider\n");
-		return -EINVAL;
-	}
-
-	if (clk_div > QSPI_CLK_DIV_MAX) {
-		dev_dbg(qspi->dev, "clock divider >%d , using /%d divider\n",
-				QSPI_CLK_DIV_MAX, QSPI_CLK_DIV_MAX + 1);
-		return -EINVAL;
-	}
-
-	dev_dbg(qspi->dev, "hz: %d, clock divider %d\n",
-			qspi->spi_max_frequency, clk_div);
+	spi->max_speed_hz = min(spi->max_speed_hz, qspi->master->max_speed_hz);
 
 	ret = pm_runtime_resume_and_get(qspi->dev);
 	if (ret < 0) {
@@ -178,18 +159,6 @@ static int ti_qspi_setup(struct spi_device *spi)
 		return ret;
 	}
 
-	clk_ctrl_reg = ti_qspi_read(qspi, QSPI_SPI_CLOCK_CNTRL_REG);
-
-	clk_ctrl_reg &= ~QSPI_CLK_EN;
-
-	/* disable SCLK */
-	ti_qspi_write(qspi, clk_ctrl_reg, QSPI_SPI_CLOCK_CNTRL_REG);
-
-	/* enable SCLK */
-	clk_mask = QSPI_CLK_EN | clk_div;
-	ti_qspi_write(qspi, clk_mask, QSPI_SPI_CLOCK_CNTRL_REG);
-	ctx_reg->clkctrl = clk_mask;
-
 	pm_runtime_mark_last_busy(qspi->dev);
 	ret = pm_runtime_put_autosuspend(qspi->dev);
 	if (ret < 0) {
@@ -200,6 +169,37 @@ static int ti_qspi_setup(struct spi_device *spi)
 	return 0;
 }
 
+static void ti_qspi_setup_clk(struct ti_qspi *qspi, u32 speed_hz)
+{
+	struct ti_qspi_regs *ctx_reg = &qspi->ctx_reg;
+	int clk_div;
+	u32 clk_ctrl_reg, clk_rate, clk_ctrl_new;
+
+	clk_rate = clk_get_rate(qspi->fclk);
+	clk_div = DIV_ROUND_UP(clk_rate, speed_hz) - 1;
+	clk_div = clamp(clk_div, 0, QSPI_CLK_DIV_MAX);
+	dev_dbg(qspi->dev, "hz: %d, clock divider %d\n", speed_hz, clk_div);
+
+	pm_runtime_resume_and_get(qspi->dev);
+
+	clk_ctrl_new = QSPI_CLK_EN | clk_div;
+	if (ctx_reg->clkctrl != clk_ctrl_new) {
+		clk_ctrl_reg = ti_qspi_read(qspi, QSPI_SPI_CLOCK_CNTRL_REG);
+
+		clk_ctrl_reg &= ~QSPI_CLK_EN;
+
+		/* disable SCLK */
+		ti_qspi_write(qspi, clk_ctrl_reg, QSPI_SPI_CLOCK_CNTRL_REG);
+
+		/* enable SCLK */
+		ti_qspi_write(qspi, clk_ctrl_new, QSPI_SPI_CLOCK_CNTRL_REG);
+		ctx_reg->clkctrl = clk_ctrl_new;
+	}
+
+	pm_runtime_mark_last_busy(qspi->dev);
+	pm_runtime_put_autosuspend(qspi->dev);
+}
+
 static void ti_qspi_restore_ctx(struct ti_qspi *qspi)
 {
 	struct ti_qspi_regs *ctx_reg = &qspi->ctx_reg;
@@ -623,8 +623,10 @@ static int ti_qspi_exec_mem_op(struct spi_mem *mem,
 
 	mutex_lock(&qspi->list_lock);
 
-	if (!qspi->mmap_enabled || qspi->current_cs != mem->spi->chip_select)
+	if (!qspi->mmap_enabled || qspi->current_cs != mem->spi->chip_select) {
+		ti_qspi_setup_clk(qspi, mem->spi->max_speed_hz);
 		ti_qspi_enable_memory_map(mem->spi);
+	}
 	ti_qspi_setup_mmap_read(mem->spi, op->cmd.opcode, op->data.buswidth,
 				op->addr.nbytes, op->dummy.nbytes);
 
@@ -701,6 +703,7 @@ static int ti_qspi_start_transfer_one(struct spi_master *master,
 		wlen = t->bits_per_word >> 3;
 		transfer_len_words = min(t->len / wlen, frame_len_words);
 
+		ti_qspi_setup_clk(qspi, t->speed_hz);
 		ret = qspi_transfer_msg(qspi, t, transfer_len_words * wlen);
 		if (ret) {
 			dev_dbg(qspi->dev, "transfer message failed\n");
@@ -851,7 +854,7 @@ static int ti_qspi_probe(struct platform_device *pdev)
 	pm_runtime_enable(&pdev->dev);
 
 	if (!of_property_read_u32(np, "spi-max-frequency", &max_freq))
-		qspi->spi_max_frequency = max_freq;
+		master->max_speed_hz = max_freq;
 
 	dma_cap_zero(mask);
 	dma_cap_set(DMA_MEMCPY, mask);