mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: Sowjanya Komatineni <skomatineni@nvidia.com>
To: <thierry.reding@gmail.com>, <jonathanh@nvidia.com>,
	<talho@nvidia.com>, <skomatineni@nvidia.com>,
	<broonie@kernel.org>, <robh+dt@kernel.org>,
	<mark.rutland@arm.com>, <kyarlagadda@nvidia.com>
Cc: <ldewangan@nvidia.com>, <linux-tegra@vger.kernel.org>,
	<linux-kernel@vger.kernel.org>, <linux-spi@vger.kernel.org>,
	<devicetree@vger.kernel.org>
Subject: [PATCH V1 23/26] spi: tegra114: add support for gpio based cs
Date: Tue, 26 Mar 2019 22:56:44 -0700	[thread overview]
Message-ID: <1553666207-11414-23-git-send-email-skomatineni@nvidia.com> (raw)
In-Reply-To: <1553666207-11414-1-git-send-email-skomatineni@nvidia.com>

This patch adds supports for chip select control using GPIO if valid
CS gpio exists rather than controlling from the SPI controller.

Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
---
 drivers/spi/spi-tegra114.c | 57 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 57 insertions(+)

diff --git a/drivers/spi/spi-tegra114.c b/drivers/spi/spi-tegra114.c
index 725d60364ec6..9b216e9d6079 100644
--- a/drivers/spi/spi-tegra114.c
+++ b/drivers/spi/spi-tegra114.c
@@ -23,6 +23,7 @@
 #include <linux/dma-mapping.h>
 #include <linux/dmapool.h>
 #include <linux/err.h>
+#include <linux/gpio.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/kernel.h>
@@ -178,6 +179,10 @@ struct tegra_spi_client_data {
 	int rx_clk_tap_delay;
 };
 
+struct tegra_spi_client_state {
+	bool cs_gpio_valid;
+};
+
 struct tegra_spi_data {
 	struct device				*dev;
 	struct spi_master			*master;
@@ -781,6 +786,7 @@ static u32 tegra_spi_setup_transfer_one(struct spi_device *spi,
 {
 	struct tegra_spi_data *tspi = spi_master_get_devdata(spi->master);
 	struct tegra_spi_client_data *cdata = spi->controller_data;
+	struct tegra_spi_client_state *cstate = spi->controller_state;
 	u32 speed = t->speed_hz;
 	u8 bits_per_word = t->bits_per_word;
 	u32 command1;
@@ -849,6 +855,12 @@ static u32 tegra_spi_setup_transfer_one(struct spi_device *spi,
 			command1 &= ~(SPI_CS_SW_HW | SPI_CS_SW_VAL);
 		}
 
+		if (cstate->cs_gpio_valid) {
+			int val = (spi->mode & SPI_CS_HIGH) ? 1 : 0;
+
+			gpio_set_value(spi->cs_gpio, val);
+		}
+
 		if (tspi->last_used_cs != spi->chip_select) {
 			if (cdata && cdata->tx_clk_tap_delay)
 				tx_tap = cdata->tx_clk_tap_delay;
@@ -950,7 +962,12 @@ static struct tegra_spi_client_data
 static void tegra_spi_cleanup(struct spi_device *spi)
 {
 	struct tegra_spi_client_data *cdata = spi->controller_data;
+	struct tegra_spi_client_state *cstate = spi->controller_state;
 
+	spi->controller_state = NULL;
+	if (cstate && cstate->cs_gpio_valid)
+		gpio_free(spi->cs_gpio);
+	kfree(cstate);
 	spi->controller_data = NULL;
 	if (spi->dev.of_node)
 		kfree(cdata);
@@ -960,6 +977,7 @@ static int tegra_spi_setup(struct spi_device *spi)
 {
 	struct tegra_spi_data *tspi = spi_master_get_devdata(spi->master);
 	struct tegra_spi_client_data *cdata = spi->controller_data;
+	struct tegra_spi_client_state *cstate = spi->controller_state;
 	u32 val;
 	unsigned long flags;
 	int ret;
@@ -970,11 +988,41 @@ static int tegra_spi_setup(struct spi_device *spi)
 		spi->mode & SPI_CPHA ? "" : "~",
 		spi->max_speed_hz);
 
+	if (!cstate) {
+		cstate = kzalloc(sizeof(*cstate), GFP_KERNEL);
+		if (!cstate)
+			return -ENOMEM;
+		spi->controller_state = cstate;
+	}
+
 	if (!cdata) {
 		cdata = tegra_spi_parse_cdata_dt(spi);
 		spi->controller_data = cdata;
 	}
 
+	if (spi->master->cs_gpios && gpio_is_valid(spi->cs_gpio)) {
+		if (!cstate->cs_gpio_valid) {
+			int gpio_flag = GPIOF_OUT_INIT_HIGH;
+
+			if (spi->mode & SPI_CS_HIGH)
+				gpio_flag = GPIOF_OUT_INIT_LOW;
+
+			ret = gpio_request_one(spi->cs_gpio, gpio_flag,
+					       "cs_gpio");
+			if (ret < 0) {
+				dev_err(&spi->dev,
+					"GPIO request failed: %d\n", ret);
+				tegra_spi_cleanup(spi);
+				return ret;
+			}
+			cstate->cs_gpio_valid = true;
+		} else {
+			int val = (spi->mode & SPI_CS_HIGH) ? 0 : 1;
+
+			gpio_set_value(spi->cs_gpio, val);
+		}
+	}
+
 	ret = pm_runtime_get_sync(tspi->dev);
 	if (ret < 0) {
 		dev_err(tspi->dev, "pm runtime failed, e = %d\n", ret);
@@ -1034,9 +1082,11 @@ static int tegra_spi_transfer_one_message(struct spi_master *master,
 	struct tegra_spi_data *tspi = spi_master_get_devdata(master);
 	struct spi_transfer *xfer;
 	struct spi_device *spi = msg->spi;
+	struct tegra_spi_client_state *cstate = spi->controller_state;
 	int single_xfer;
 	int ret;
 	bool skip = false;
+	int cs_val;
 
 	msg->status = 0;
 	msg->actual_length = 0;
@@ -1093,7 +1143,10 @@ static int tegra_spi_transfer_one_message(struct spi_master *master,
 		msg->actual_length += xfer->len;
 
 complete_xfer:
+		cs_val = (spi->mode & SPI_CS_HIGH) ? 0 : 1;
 		if (ret < 0 || skip) {
+			if (cstate->cs_gpio_valid)
+				gpio_set_value(spi->cs_gpio, cs_val);
 			tegra_spi_writel(tspi, tspi->def_command1_reg,
 					SPI_COMMAND1);
 			tegra_spi_transfer_delay(xfer->delay_usecs);
@@ -1103,11 +1156,15 @@ static int tegra_spi_transfer_one_message(struct spi_master *master,
 			if (xfer->cs_change)
 				tspi->cs_control = spi;
 			else {
+				if (cstate->cs_gpio_valid)
+					gpio_set_value(spi->cs_gpio, cs_val);
 				tegra_spi_writel(tspi, tspi->def_command1_reg,
 						SPI_COMMAND1);
 				tegra_spi_transfer_delay(xfer->delay_usecs);
 			}
 		} else if (xfer->cs_change) {
+			if (cstate->cs_gpio_valid)
+				gpio_set_value(spi->cs_gpio, cs_val);
 			tegra_spi_writel(tspi, tspi->def_command1_reg,
 					SPI_COMMAND1);
 			tegra_spi_transfer_delay(xfer->delay_usecs);
-- 
2.7.4


  parent reply	other threads:[~2019-03-27  5:57 UTC|newest]

Thread overview: 47+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-03-27  5:56 [PATCH V1 01/26] spi: tegra114: fix PIO transfer Sowjanya Komatineni
2019-03-27  5:56 ` [PATCH V1 02/26] spi: tegra114: clear packed bit for unpacked mode Sowjanya Komatineni
2019-04-01  8:54   ` Applied "spi: tegra114: clear packed bit for unpacked mode" to the spi tree Mark Brown
2019-03-27  5:56 ` [PATCH V1 03/26] spi: tegra114: fix for unpacked mode transfers Sowjanya Komatineni
2019-04-01  8:54   ` Applied "spi: tegra114: fix for unpacked mode transfers" to the spi tree Mark Brown
2019-03-27  5:56 ` [PATCH V1 04/26] spi: tegra114: use packed mode for 32 bits per word Sowjanya Komatineni
2019-04-01  7:39   ` Mark Brown
2019-04-01 18:38     ` Sowjanya Komatineni
2019-04-01  8:54   ` Applied "spi: tegra114: use packed mode for 32 bits per word" to the spi tree Mark Brown
2019-03-27  5:56 ` [PATCH V1 05/26] spi: tegra114: use unpacked mode for below 4 byte transfers Sowjanya Komatineni
2019-04-01  8:26   ` Mark Brown
2019-03-27  5:56 ` [PATCH V1 06/26] spi: tegra114: terminate dma and reset on transfer timeout Sowjanya Komatineni
2019-04-01  8:54   ` Applied "spi: tegra114: terminate dma and reset on transfer timeout" to the spi tree Mark Brown
2019-03-27  5:56 ` [PATCH V1 07/26] spi: tegra114: flush fifos Sowjanya Komatineni
2019-04-01  8:54   ` Applied "spi: tegra114: flush fifos" to the spi tree Mark Brown
2019-03-27  5:56 ` [PATCH V1 08/26] spi: tegra114: configure dma burst size to fifo trig level Sowjanya Komatineni
2019-03-27  5:56 ` [PATCH V1 09/26] spi: tegra114: dump SPI registers during timeout Sowjanya Komatineni
2019-04-01  7:39   ` Mark Brown
2019-03-27  5:56 ` [PATCH V1 10/26] spi: tegra114: avoid reset call in atomic context Sowjanya Komatineni
2019-03-27  5:56 ` [PATCH V1 11/26] spi: tegra114: reset controller on probe Sowjanya Komatineni
2019-04-01  8:54   ` Applied "spi: tegra114: reset controller on probe" to the spi tree Mark Brown
2019-03-27  5:56 ` [PATCH V1 12/26] spi: tegra114: add SPI_LSB_FIRST support Sowjanya Komatineni
2019-04-01  8:54   ` Applied "spi: tegra114: add SPI_LSB_FIRST support" to the spi tree Mark Brown
2019-03-27  5:56 ` [PATCH V1 13/26] spi: tegra114: add dual mode support Sowjanya Komatineni
2019-03-27  5:56 ` [PATCH V1 14/26] spi: tegra114: add 3 wire transfer " Sowjanya Komatineni
2019-03-27  5:56 ` [PATCH V1 15/26] spi: tegra114: set supported bits_per_word Sowjanya Komatineni
2019-03-27  5:56 ` [PATCH V1 16/26] spi: tegra114: set bus number based on id Sowjanya Komatineni
2019-03-27  5:56 ` [PATCH V1 17/26] spi: tegra114: add support for interrupt mask Sowjanya Komatineni
2019-03-27  5:56 ` [PATCH V1 18/26] spi: tegra114: add support for hw based cs Sowjanya Komatineni
2019-04-01  7:48   ` Mark Brown
2019-04-01 18:40     ` Sowjanya Komatineni
2019-03-27  5:56 ` [PATCH V1 19/26] DT bindings: spi: add spi client device properties Sowjanya Komatineni
2019-04-01  7:37   ` Mark Brown
2019-04-01 17:59     ` Sowjanya Komatineni
2019-04-02  4:52       ` Mark Brown
2019-03-27  5:56 ` [PATCH V1 20/26] spi: tegra114: add support for tuning HW CS timing Sowjanya Komatineni
2019-03-27  5:56 ` [PATCH V1 21/26] DT bindings: spi: add tx/rx clock delay SPI client properties Sowjanya Komatineni
2019-03-31  6:42   ` Rob Herring
2019-04-02 20:27     ` Sowjanya Komatineni
2019-03-27  5:56 ` [PATCH V1 22/26] spi: tegra114: add support for tuning clock delay Sowjanya Komatineni
2019-03-27  5:56 ` Sowjanya Komatineni [this message]
2019-03-27  5:56 ` [PATCH V1 24/26] spi: tegra114: de-assert CS before SPI mode is reset to its default Sowjanya Komatineni
2019-04-01  7:49   ` Mark Brown
2019-04-01 18:07     ` Sowjanya Komatineni
2019-04-02  4:52       ` Mark Brown
2019-03-27  5:56 ` [PATCH V1 25/26] spi: expand mode and mode_bits support Sowjanya Komatineni
2019-03-27  5:56 ` [PATCH V1 26/26] spi: tegra114: add support for LSBYTE_FIRST Sowjanya Komatineni

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1553666207-11414-23-git-send-email-skomatineni@nvidia.com \
    --to=skomatineni@nvidia.com \
    --cc=broonie@kernel.org \
    --cc=devicetree@vger.kernel.org \
    --cc=jonathanh@nvidia.com \
    --cc=kyarlagadda@nvidia.com \
    --cc=ldewangan@nvidia.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-spi@vger.kernel.org \
    --cc=linux-tegra@vger.kernel.org \
    --cc=mark.rutland@arm.com \
    --cc=robh+dt@kernel.org \
    --cc=talho@nvidia.com \
    --cc=thierry.reding@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox

all inboxes | Powered by JetHome®