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Subject[PATCH V4 4/4] spi: spi-geni-qcom: Plugin API to assert and de-assert Chipselect
Date
Plugin set cs API to the SPI framework so that
framework can do chipselect assert de-assert
during SPI transfers.

Signed-off-by: Dilip Kota <dkota@codeaurora.org>
---
drivers/spi/spi-geni-qcom.c | 65 ++++++++++++++++++++++++++++++++-------------
1 file changed, 46 insertions(+), 19 deletions(-)

diff --git a/drivers/spi/spi-geni-qcom.c b/drivers/spi/spi-geni-qcom.c
index 949b853..5cfb4f2 100644
--- a/drivers/spi/spi-geni-qcom.c
+++ b/drivers/spi/spi-geni-qcom.c
@@ -66,6 +66,13 @@

static irqreturn_t geni_spi_isr(int irq, void *data);

+/* SPI M_COMMAND OPCODE */
+enum spi_mcmd_code {
+ CMD_NONE,
+ CMD_XFER,
+ CMD_CS,
+};
+
struct spi_geni_master {
struct geni_se se;
struct device *dev;
@@ -81,8 +88,12 @@ struct spi_geni_master {
struct completion xfer_done;
unsigned int oversampling;
spinlock_t lock;
+ unsigned int cur_mcmd;
};

+static void handle_fifo_timeout(struct spi_master *spi,
+ struct spi_message *msg);
+
static int get_spi_clk_cfg(unsigned int speed_hz,
struct spi_geni_master *mas,
unsigned int *clk_idx,
@@ -113,6 +124,31 @@ static int get_spi_clk_cfg(unsigned int speed_hz,
return ret;
}

+static void spi_geni_set_cs(struct spi_device *slv, bool set_flag)
+{
+ struct spi_geni_master *mas = spi_master_get_devdata(slv->master);
+ struct spi_master *spi = dev_get_drvdata(mas->dev);
+ struct geni_se *se = &mas->se;
+ unsigned long timeout;
+
+ reinit_completion(&mas->xfer_done);
+ pm_runtime_get_sync(mas->dev);
+ if (!(slv->mode & SPI_CS_HIGH))
+ set_flag = !set_flag;
+
+ mas->cur_mcmd = CMD_CS;
+ if (set_flag)
+ geni_se_setup_m_cmd(se, SPI_CS_ASSERT, 0);
+ else
+ geni_se_setup_m_cmd(se, SPI_CS_DEASSERT, 0);
+
+ timeout = wait_for_completion_timeout(&mas->xfer_done, HZ);
+ if (!timeout)
+ handle_fifo_timeout(spi, NULL);
+
+ pm_runtime_put(mas->dev);
+}
+
static void spi_setup_word_len(struct spi_geni_master *mas, u16 mode,
unsigned int bits_per_word)
{
@@ -249,7 +285,7 @@ static void setup_fifo_xfer(struct spi_transfer *xfer,
struct spi_geni_master *mas,
u16 mode, struct spi_master *spi)
{
- u32 m_cmd = 0, m_param = 0;
+ u32 m_cmd = 0;
u32 spi_tx_cfg, trans_len;
struct geni_se *se = &mas->se;

@@ -305,21 +341,7 @@ static void setup_fifo_xfer(struct spi_transfer *xfer,
trans_len = (xfer->len / bytes_per_word) & TRANS_LEN_MSK;
}

- /*
- * If CS change flag is set, then toggle the CS line in between
- * transfers and keep CS asserted after the last transfer.
- * Else if keep CS flag asserted in between transfers and de-assert
- * CS after the last message.
- */
- if (xfer->cs_change) {
- if (list_is_last(&xfer->transfer_list,
- &spi->cur_msg->transfers))
- m_param = FRAGMENTATION;
- } else {
- if (!list_is_last(&xfer->transfer_list,
- &spi->cur_msg->transfers))
- m_param = FRAGMENTATION;
- }
+

mas->cur_xfer = xfer;
if (m_cmd & SPI_TX_ONLY) {
@@ -332,8 +354,8 @@ static void setup_fifo_xfer(struct spi_transfer *xfer,
mas->rx_rem_bytes = xfer->len;
}
writel(spi_tx_cfg, se->base + SE_SPI_TRANS_CFG);
- geni_se_setup_m_cmd(se, m_cmd, m_param);
-
+ mas->cur_mcmd = CMD_XFER;
+ geni_se_setup_m_cmd(se, m_cmd, FRAGMENTATION);
/*
* TX_WATERMARK_REG should be set after SPI configuration and
* setting up GENI SE engine, as driver starts data transfer
@@ -489,7 +511,11 @@ static irqreturn_t geni_spi_isr(int irq, void *data)
ret = geni_spi_handle_tx(mas);

if (m_irq & M_CMD_DONE_EN) {
- spi_finalize_current_transfer(spi);
+ if (mas->cur_mcmd == CMD_XFER)
+ spi_finalize_current_transfer(spi);
+ else if (mas->cur_mcmd == CMD_CS)
+ complete(&mas->xfer_done);
+ mas->cur_mcmd = CMD_NONE;
/*
* If this happens, then a CMD_DONE came before all the Tx
* buffer bytes were sent out. This is unusual, log this
@@ -572,6 +598,7 @@ static int spi_geni_probe(struct platform_device *pdev)
spi->transfer_one = spi_geni_transfer_one;
spi->auto_runtime_pm = true;
spi->handle_err = handle_fifo_timeout;
+ spi->set_cs = spi_geni_set_cs;

init_completion(&mas->xfer_done);
spin_lock_init(&mas->lock);
--
Qualcomm Datacenter Technologies as an affiliate of Qualcomm Technologies, Inc.
Qualcomm Technologies, Inc. is a member of the
Code Aurora Forum, a Linux Foundation Collaborative Project.
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