From 1543e317f1da31b75942316931e8f491a8920811 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Thu, 04 Jan 2024 10:08:02 +0000
Subject: [PATCH] disable FB

---
 kernel/drivers/spi/spi-atmel.c |  312 ++++++++++++++++++++++++----------------------------
 1 files changed, 144 insertions(+), 168 deletions(-)

diff --git a/kernel/drivers/spi/spi-atmel.c b/kernel/drivers/spi/spi-atmel.c
index 2254e36..1db43cb 100644
--- a/kernel/drivers/spi/spi-atmel.c
+++ b/kernel/drivers/spi/spi-atmel.c
@@ -1,11 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Driver for Atmel AT32 and AT91 SPI Controllers
  *
  * Copyright (C) 2006 Atmel Corporation
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
  */
 
 #include <linux/kernel.h>
@@ -19,14 +16,13 @@
 #include <linux/interrupt.h>
 #include <linux/spi/spi.h>
 #include <linux/slab.h>
-#include <linux/platform_data/dma-atmel.h>
 #include <linux/of.h>
 
 #include <linux/io.h>
-#include <linux/gpio.h>
-#include <linux/of_gpio.h>
+#include <linux/gpio/consumer.h>
 #include <linux/pinctrl/consumer.h>
 #include <linux/pm_runtime.h>
+#include <trace/events/spi.h>
 
 /* SPI register offsets */
 #define SPI_CR					0x0000
@@ -225,37 +221,13 @@
 	  | SPI_BF(name, value))
 
 /* Register access macros */
-#ifdef CONFIG_AVR32
-#define spi_readl(port, reg) \
-	__raw_readl((port)->regs + SPI_##reg)
-#define spi_writel(port, reg, value) \
-	__raw_writel((value), (port)->regs + SPI_##reg)
-
-#define spi_readw(port, reg) \
-	__raw_readw((port)->regs + SPI_##reg)
-#define spi_writew(port, reg, value) \
-	__raw_writew((value), (port)->regs + SPI_##reg)
-
-#define spi_readb(port, reg) \
-	__raw_readb((port)->regs + SPI_##reg)
-#define spi_writeb(port, reg, value) \
-	__raw_writeb((value), (port)->regs + SPI_##reg)
-#else
 #define spi_readl(port, reg) \
 	readl_relaxed((port)->regs + SPI_##reg)
 #define spi_writel(port, reg, value) \
 	writel_relaxed((value), (port)->regs + SPI_##reg)
-
-#define spi_readw(port, reg) \
-	readw_relaxed((port)->regs + SPI_##reg)
 #define spi_writew(port, reg, value) \
 	writew_relaxed((value), (port)->regs + SPI_##reg)
 
-#define spi_readb(port, reg) \
-	readb_relaxed((port)->regs + SPI_##reg)
-#define spi_writeb(port, reg, value) \
-	writeb_relaxed((value), (port)->regs + SPI_##reg)
-#endif
 /* use PIO for small transfers, avoiding DMA setup/teardown overhead and
  * cache operations; better heuristics consider wordsize and bitrate.
  */
@@ -302,16 +274,16 @@
 
 	bool			use_dma;
 	bool			use_pdc;
-	bool			use_cs_gpios;
 
 	bool			keep_cs;
 
 	u32			fifo_size;
+	u8			native_cs_free;
+	u8			native_cs_for_gpio;
 };
 
 /* Controller-specific per-slave state */
 struct atmel_spi_device {
-	unsigned int		npcs_pin;
 	u32			csr;
 };
 
@@ -338,11 +310,9 @@
  * transmitted")  Not so!  Workaround uses nCSx pins as GPIOs; or newer
  * controllers have CSAAT and friends.
  *
- * Since the CSAAT functionality is a bit weird on newer controllers as
- * well, we use GPIO to control nCSx pins on all controllers, updating
- * MR.PCS to avoid confusing the controller.  Using GPIOs also lets us
- * support active-high chipselects despite the controller's belief that
- * only active-low devices/systems exists.
+ * Even controller newer than ar91rm9200, using GPIOs can make sens as
+ * it lets us support active-high chipselects despite the controller's
+ * belief that only active-low devices/systems exists.
  *
  * However, at91rm9200 has a second erratum whereby nCS0 doesn't work
  * right when driven with GPIO.  ("Mode Fault does not allow more than one
@@ -354,31 +324,36 @@
 static void cs_activate(struct atmel_spi *as, struct spi_device *spi)
 {
 	struct atmel_spi_device *asd = spi->controller_state;
-	unsigned active = spi->mode & SPI_CS_HIGH;
+	int chip_select;
 	u32 mr;
 
+	if (spi->cs_gpiod)
+		chip_select = as->native_cs_for_gpio;
+	else
+		chip_select = spi->chip_select;
+
 	if (atmel_spi_is_v2(as)) {
-		spi_writel(as, CSR0 + 4 * spi->chip_select, asd->csr);
+		spi_writel(as, CSR0 + 4 * chip_select, asd->csr);
 		/* For the low SPI version, there is a issue that PDC transfer
 		 * on CS1,2,3 needs SPI_CSR0.BITS config as SPI_CSR1,2,3.BITS
 		 */
 		spi_writel(as, CSR0, asd->csr);
 		if (as->caps.has_wdrbt) {
 			spi_writel(as, MR,
-					SPI_BF(PCS, ~(0x01 << spi->chip_select))
+					SPI_BF(PCS, ~(0x01 << chip_select))
 					| SPI_BIT(WDRBT)
 					| SPI_BIT(MODFDIS)
 					| SPI_BIT(MSTR));
 		} else {
 			spi_writel(as, MR,
-					SPI_BF(PCS, ~(0x01 << spi->chip_select))
+					SPI_BF(PCS, ~(0x01 << chip_select))
 					| SPI_BIT(MODFDIS)
 					| SPI_BIT(MSTR));
 		}
 
 		mr = spi_readl(as, MR);
-		if (as->use_cs_gpios)
-			gpio_set_value(asd->npcs_pin, active);
+		if (spi->cs_gpiod)
+			gpiod_set_value(spi->cs_gpiod, 1);
 	} else {
 		u32 cpol = (spi->mode & SPI_CPOL) ? SPI_BIT(CPOL) : 0;
 		int i;
@@ -393,40 +368,40 @@
 		}
 
 		mr = spi_readl(as, MR);
-		mr = SPI_BFINS(PCS, ~(1 << spi->chip_select), mr);
-		if (as->use_cs_gpios && spi->chip_select != 0)
-			gpio_set_value(asd->npcs_pin, active);
+		mr = SPI_BFINS(PCS, ~(1 << chip_select), mr);
+		if (spi->cs_gpiod)
+			gpiod_set_value(spi->cs_gpiod, 1);
 		spi_writel(as, MR, mr);
 	}
 
-	dev_dbg(&spi->dev, "activate %u%s, mr %08x\n",
-			asd->npcs_pin, active ? " (high)" : "",
-			mr);
+	dev_dbg(&spi->dev, "activate NPCS, mr %08x\n", mr);
 }
 
 static void cs_deactivate(struct atmel_spi *as, struct spi_device *spi)
 {
-	struct atmel_spi_device *asd = spi->controller_state;
-	unsigned active = spi->mode & SPI_CS_HIGH;
+	int chip_select;
 	u32 mr;
+
+	if (spi->cs_gpiod)
+		chip_select = as->native_cs_for_gpio;
+	else
+		chip_select = spi->chip_select;
 
 	/* only deactivate *this* device; sometimes transfers to
 	 * another device may be active when this routine is called.
 	 */
 	mr = spi_readl(as, MR);
-	if (~SPI_BFEXT(PCS, mr) & (1 << spi->chip_select)) {
+	if (~SPI_BFEXT(PCS, mr) & (1 << chip_select)) {
 		mr = SPI_BFINS(PCS, 0xf, mr);
 		spi_writel(as, MR, mr);
 	}
 
-	dev_dbg(&spi->dev, "DEactivate %u%s, mr %08x\n",
-			asd->npcs_pin, active ? " (low)" : "",
-			mr);
+	dev_dbg(&spi->dev, "DEactivate NPCS, mr %08x\n", mr);
 
-	if (!as->use_cs_gpios)
+	if (!spi->cs_gpiod)
 		spi_writel(as, CR, SPI_BIT(LASTXFER));
-	else if (atmel_spi_is_v2(as) || spi->chip_select != 0)
-		gpio_set_value(asd->npcs_pin, !active);
+	else
+		gpiod_set_value(spi->cs_gpiod, 0);
 }
 
 static void atmel_spi_lock(struct atmel_spi *as) __acquires(&as->lock)
@@ -535,29 +510,21 @@
 	dma_cap_zero(mask);
 	dma_cap_set(DMA_SLAVE, mask);
 
-	master->dma_tx = dma_request_slave_channel_reason(dev, "tx");
+	master->dma_tx = dma_request_chan(dev, "tx");
 	if (IS_ERR(master->dma_tx)) {
-		err = PTR_ERR(master->dma_tx);
-		if (err == -EPROBE_DEFER) {
-			dev_warn(dev, "no DMA channel available at the moment\n");
-			goto error_clear;
-		}
-		dev_err(dev,
-			"DMA TX channel not available, SPI unable to use DMA\n");
-		err = -EBUSY;
+		err = dev_err_probe(dev, PTR_ERR(master->dma_tx),
+				    "No TX DMA channel, DMA is disabled\n");
 		goto error_clear;
 	}
 
-	/*
-	 * No reason to check EPROBE_DEFER here since we have already requested
-	 * tx channel. If it fails here, it's for another reason.
-	 */
-	master->dma_rx = dma_request_slave_channel(dev, "rx");
-
-	if (!master->dma_rx) {
-		dev_err(dev,
-			"DMA RX channel not available, SPI unable to use DMA\n");
-		err = -EBUSY;
+	master->dma_rx = dma_request_chan(dev, "rx");
+	if (IS_ERR(master->dma_rx)) {
+		err = PTR_ERR(master->dma_rx);
+		/*
+		 * No reason to check EPROBE_DEFER here since we have already
+		 * requested tx channel.
+		 */
+		dev_err(dev, "No RX DMA channel, DMA is disabled\n");
 		goto error;
 	}
 
@@ -572,7 +539,7 @@
 
 	return 0;
 error:
-	if (master->dma_rx)
+	if (!IS_ERR(master->dma_rx))
 		dma_release_channel(master->dma_rx);
 	if (!IS_ERR(master->dma_tx))
 		dma_release_channel(master->dma_tx);
@@ -737,6 +704,7 @@
 static int atmel_spi_next_xfer_dma_submit(struct spi_master *master,
 				struct spi_transfer *xfer,
 				u32 *plen)
+	__must_hold(&as->lock)
 {
 	struct atmel_spi	*as = spi_master_get_devdata(master);
 	struct dma_chan		*rxchan = master->dma_rx;
@@ -852,6 +820,12 @@
 {
 	u32			scbr, csr;
 	unsigned long		bus_hz;
+	int chip_select;
+
+	if (spi->cs_gpiod)
+		chip_select = as->native_cs_for_gpio;
+	else
+		chip_select = spi->chip_select;
 
 	/* v1 chips start out at half the peripheral bus speed. */
 	bus_hz = as->spi_clk;
@@ -880,9 +854,10 @@
 			xfer->speed_hz, scbr, bus_hz);
 		return -EINVAL;
 	}
-	csr = spi_readl(as, CSR0 + 4 * spi->chip_select);
+	csr = spi_readl(as, CSR0 + 4 * chip_select);
 	csr = SPI_BFINS(SCBR, scbr, csr);
-	spi_writel(as, CSR0 + 4 * spi->chip_select, csr);
+	spi_writel(as, CSR0 + 4 * chip_select, csr);
+	xfer->effective_speed_hz = bus_hz / scbr;
 
 	return 0;
 }
@@ -1181,46 +1156,105 @@
 	return ret;
 }
 
+static int atmel_word_delay_csr(struct spi_device *spi, struct atmel_spi *as)
+{
+	struct spi_delay *delay = &spi->word_delay;
+	u32 value = delay->value;
+
+	switch (delay->unit) {
+	case SPI_DELAY_UNIT_NSECS:
+		value /= 1000;
+		break;
+	case SPI_DELAY_UNIT_USECS:
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return (as->spi_clk / 1000000 * value) >> 5;
+}
+
+static void initialize_native_cs_for_gpio(struct atmel_spi *as)
+{
+	int i;
+	struct spi_master *master = platform_get_drvdata(as->pdev);
+
+	if (!as->native_cs_free)
+		return; /* already initialized */
+
+	if (!master->cs_gpiods)
+		return; /* No CS GPIO */
+
+	/*
+	 * On the first version of the controller (AT91RM9200), CS0
+	 * can't be used associated with GPIO
+	 */
+	if (atmel_spi_is_v2(as))
+		i = 0;
+	else
+		i = 1;
+
+	for (; i < 4; i++)
+		if (master->cs_gpiods[i])
+			as->native_cs_free |= BIT(i);
+
+	if (as->native_cs_free)
+		as->native_cs_for_gpio = ffs(as->native_cs_free);
+}
+
 static int atmel_spi_setup(struct spi_device *spi)
 {
 	struct atmel_spi	*as;
 	struct atmel_spi_device	*asd;
 	u32			csr;
 	unsigned int		bits = spi->bits_per_word;
-	unsigned int		npcs_pin;
+	int chip_select;
+	int			word_delay_csr;
 
 	as = spi_master_get_devdata(spi->master);
 
 	/* see notes above re chipselect */
-	if (!as->use_cs_gpios && (spi->mode & SPI_CS_HIGH)) {
+	if (!spi->cs_gpiod && (spi->mode & SPI_CS_HIGH)) {
 		dev_warn(&spi->dev, "setup: non GPIO CS can't be active-high\n");
 		return -EINVAL;
 	}
+
+	/* Setup() is called during spi_register_controller(aka
+	 * spi_register_master) but after all membmers of the cs_gpiod
+	 * array have been filled, so we can looked for which native
+	 * CS will be free for using with GPIO
+	 */
+	initialize_native_cs_for_gpio(as);
+
+	if (spi->cs_gpiod && as->native_cs_free) {
+		dev_err(&spi->dev,
+			"No native CS available to support this GPIO CS\n");
+		return -EBUSY;
+	}
+
+	if (spi->cs_gpiod)
+		chip_select = as->native_cs_for_gpio;
+	else
+		chip_select = spi->chip_select;
 
 	csr = SPI_BF(BITS, bits - 8);
 	if (spi->mode & SPI_CPOL)
 		csr |= SPI_BIT(CPOL);
 	if (!(spi->mode & SPI_CPHA))
 		csr |= SPI_BIT(NCPHA);
-	if (!as->use_cs_gpios)
+
+	if (!spi->cs_gpiod)
 		csr |= SPI_BIT(CSAAT);
-
-	/* DLYBS is mostly irrelevant since we manage chipselect using GPIOs.
-	 *
-	 * DLYBCT would add delays between words, slowing down transfers.
-	 * It could potentially be useful to cope with DMA bottlenecks, but
-	 * in those cases it's probably best to just use a lower bitrate.
-	 */
 	csr |= SPI_BF(DLYBS, 0);
-	csr |= SPI_BF(DLYBCT, 0);
 
-	/* chipselect must have been muxed as GPIO (e.g. in board setup) */
-	npcs_pin = (unsigned long)spi->controller_data;
+	word_delay_csr = atmel_word_delay_csr(spi, as);
+	if (word_delay_csr < 0)
+		return word_delay_csr;
 
-	if (!as->use_cs_gpios)
-		npcs_pin = spi->chip_select;
-	else if (gpio_is_valid(spi->cs_gpio))
-		npcs_pin = spi->cs_gpio;
+	/* DLYBCT adds delays between words.  This is useful for slow devices
+	 * that need a bit of time to setup the next transfer.
+	 */
+	csr |= SPI_BF(DLYBCT, word_delay_csr);
 
 	asd = spi->controller_state;
 	if (!asd) {
@@ -1228,11 +1262,6 @@
 		if (!asd)
 			return -ENOMEM;
 
-		if (as->use_cs_gpios)
-			gpio_direction_output(npcs_pin,
-					      !(spi->mode & SPI_CS_HIGH));
-
-		asd->npcs_pin = npcs_pin;
 		spi->controller_state = asd;
 	}
 
@@ -1243,7 +1272,7 @@
 		bits, spi->mode, spi->chip_select, csr);
 
 	if (!atmel_spi_is_v2(as))
-		spi_writel(as, CSR0 + 4 * spi->chip_select, csr);
+		spi_writel(as, CSR0 + 4 * chip_select, csr);
 
 	return 0;
 }
@@ -1372,8 +1401,7 @@
 		&& as->use_pdc)
 		atmel_spi_dma_unmap_xfer(master, xfer);
 
-	if (xfer->delay_usecs)
-		udelay(xfer->delay_usecs);
+	spi_transfer_delay_exec(xfer);
 
 	if (xfer->cs_change) {
 		if (list_is_last(&xfer->transfer_list,
@@ -1411,9 +1439,13 @@
 	msg->actual_length = 0;
 
 	list_for_each_entry(xfer, &msg->transfers, transfer_list) {
+		trace_spi_transfer_start(msg, xfer);
+
 		ret = atmel_spi_one_transfer(master, msg, xfer);
 		if (ret)
 			goto msg_done;
+
+		trace_spi_transfer_stop(msg, xfer);
 	}
 
 	if (as->use_pdc)
@@ -1467,41 +1499,6 @@
 	as->caps.has_pdc_support = version < 0x212;
 }
 
-/*-------------------------------------------------------------------------*/
-static int atmel_spi_gpio_cs(struct platform_device *pdev)
-{
-	struct spi_master	*master = platform_get_drvdata(pdev);
-	struct atmel_spi	*as = spi_master_get_devdata(master);
-	struct device_node	*np = master->dev.of_node;
-	int			i;
-	int			ret = 0;
-	int			nb = 0;
-
-	if (!as->use_cs_gpios)
-		return 0;
-
-	if (!np)
-		return 0;
-
-	nb = of_gpio_named_count(np, "cs-gpios");
-	for (i = 0; i < nb; i++) {
-		int cs_gpio = of_get_named_gpio(pdev->dev.of_node,
-						"cs-gpios", i);
-
-		if (cs_gpio == -EPROBE_DEFER)
-			return cs_gpio;
-
-		if (gpio_is_valid(cs_gpio)) {
-			ret = devm_gpio_request(&pdev->dev, cs_gpio,
-						dev_name(&pdev->dev));
-			if (ret)
-				return ret;
-		}
-	}
-
-	return 0;
-}
-
 static void atmel_spi_init(struct atmel_spi *as)
 {
 	spi_writel(as, CR, SPI_BIT(SWRST));
@@ -1548,17 +1545,17 @@
 		return PTR_ERR(clk);
 
 	/* setup spi core then atmel-specific driver state */
-	ret = -ENOMEM;
 	master = spi_alloc_master(&pdev->dev, sizeof(*as));
 	if (!master)
-		goto out_free;
+		return -ENOMEM;
 
 	/* the spi->mode bits understood by this driver: */
+	master->use_gpio_descriptors = true;
 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
 	master->bits_per_word_mask = SPI_BPW_RANGE_MASK(8, 16);
 	master->dev.of_node = pdev->dev.of_node;
 	master->bus_num = pdev->id;
-	master->num_chipselect = master->dev.of_node ? 0 : 4;
+	master->num_chipselect = 4;
 	master->setup = atmel_spi_setup;
 	master->flags = (SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX);
 	master->transfer_one_message = atmel_spi_transfer_one_message;
@@ -1585,18 +1582,6 @@
 	init_completion(&as->xfer_completion);
 
 	atmel_get_caps(as);
-
-	as->use_cs_gpios = true;
-	if (atmel_spi_is_v2(as) &&
-	    pdev->dev.of_node &&
-	    !of_get_property(pdev->dev.of_node, "cs-gpios", NULL)) {
-		as->use_cs_gpios = false;
-		master->num_chipselect = 4;
-	}
-
-	ret = atmel_spi_gpio_cs(pdev);
-	if (ret)
-		goto out_unmap_regs;
 
 	as->use_dma = false;
 	as->use_pdc = false;
@@ -1691,7 +1676,6 @@
 	clk_disable_unprepare(clk);
 out_free_irq:
 out_unmap_regs:
-out_free:
 	spi_master_put(master);
 	return ret;
 }
@@ -1761,10 +1745,8 @@
 
 	/* Stop the queue running */
 	ret = spi_master_suspend(master);
-	if (ret) {
-		dev_warn(dev, "cannot suspend master\n");
+	if (ret)
 		return ret;
-	}
 
 	if (!pm_runtime_suspended(dev))
 		atmel_spi_runtime_suspend(dev);
@@ -1793,11 +1775,7 @@
 	}
 
 	/* Start the queue running */
-	ret = spi_master_resume(master);
-	if (ret)
-		dev_err(dev, "problem starting queue (%d)\n", ret);
-
-	return ret;
+	return spi_master_resume(master);
 }
 #endif
 
@@ -1811,20 +1789,18 @@
 #define ATMEL_SPI_PM_OPS	NULL
 #endif
 
-#if defined(CONFIG_OF)
 static const struct of_device_id atmel_spi_dt_ids[] = {
 	{ .compatible = "atmel,at91rm9200-spi" },
 	{ /* sentinel */ }
 };
 
 MODULE_DEVICE_TABLE(of, atmel_spi_dt_ids);
-#endif
 
 static struct platform_driver atmel_spi_driver = {
 	.driver		= {
 		.name	= "atmel_spi",
 		.pm	= ATMEL_SPI_PM_OPS,
-		.of_match_table	= of_match_ptr(atmel_spi_dt_ids),
+		.of_match_table	= atmel_spi_dt_ids,
 	},
 	.probe		= atmel_spi_probe,
 	.remove		= atmel_spi_remove,

--
Gitblit v1.6.2