[PATCH v9 09/38] dma: cirrus: Convert to DT for Cirrus EP93xx

Nikita Shubin via B4 Relay
2024-03-26T09:20:41Z

Convert Cirrus EP93xx DMA to device tree usage:

- add OF ID match table with data
- add of_probe for device tree
- add xlate for m2m/m2p
- drop subsys_initcall code
- drop platform probe
- drop platform structs usage

From now on it only supports device tree probing.

Co-developed-by: Alexander Sverdlin <alexander.sverdlin@gmail.com>
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@gmail.com>
Signed-off-by: Nikita Shubin <nikita.shubin@maquefel.me>
---
drivers/dma/ep93xx_dma.c | 239 ++++++++++++++++++++++++-------
include/linux/platform_data/dma-ep93xx.h | 6 +
2 files changed, 191 insertions(+), 54 deletions(-)

diff --git a/drivers/dma/ep93xx_dma.c b/drivers/dma/ep93xx_dma.c
index d6c60635e90d..17c8e2badee2 100644
--- a/drivers/dma/ep93xx_dma.c
+++ b/drivers/dma/ep93xx_dma.c
@@ -20,6 +20,8 @@
#include <linux/dmaengine.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
+#include <linux/of_dma.h>
+#include <linux/overflow.h>
#include <linux/platform_device.h>
#include <linux/slab.h>

@@ -104,6 +106,11 @@
#define DMA_MAX_CHAN_BYTES 0xffff
#define DMA_MAX_CHAN_DESCRIPTORS 32

+enum ep93xx_dma_type {
+ M2P_DMA,
+ M2M_DMA,
+};
+
struct ep93xx_dma_engine;
static int ep93xx_dma_slave_config_write(struct dma_chan *chan,
enum dma_transfer_direction dir,
@@ -129,11 +136,17 @@ struct ep93xx_dma_desc {
struct list_head node;
};

+struct ep93xx_dma_chan_cfg {
+ u8 port;
+ enum dma_transfer_direction dir;
+};
+
/**
* struct ep93xx_dma_chan - an EP93xx DMA M2P/M2M channel
* @chan: dmaengine API channel
* @edma: pointer to the engine device
* @regs: memory mapped registers
+ * @dma_cfg: channel number, direction
* @irq: interrupt number of the channel
* @clk: clock used by this channel
* @tasklet: channel specific tasklet used for callbacks
@@ -157,14 +170,12 @@ struct ep93xx_dma_desc {
* descriptor in the chain. When a descriptor is moved to the @active queue,
* the first and chained descriptors are flattened into a single list.
*
- * @chan.private holds pointer to &struct ep93xx_dma_data which contains
- * necessary channel configuration information. For memcpy channels this must
- * be %NULL.
*/
struct ep93xx_dma_chan {
struct dma_chan chan;
const struct ep93xx_dma_engine *edma;
void __iomem *regs;
+ struct ep93xx_dma_chan_cfg dma_cfg;
int irq;
struct clk *clk;
struct tasklet_struct tasklet;
@@ -216,6 +227,11 @@ struct ep93xx_dma_engine {
struct ep93xx_dma_chan channels[] __counted_by(num_channels);
};

+struct ep93xx_edma_data {
+ u32 id;
+ size_t num_channels;
+};
+
static inline struct device *chan2dev(struct ep93xx_dma_chan *edmac)
{
return &edmac->chan.dev->device;
@@ -318,10 +334,9 @@ static void m2p_set_control(struct ep93xx_dma_chan *edmac, u32 control)

static int m2p_hw_setup(struct ep93xx_dma_chan *edmac)
{
- struct ep93xx_dma_data *data = edmac->chan.private;
u32 control;

- writel(data->port & 0xf, edmac->regs + M2P_PPALLOC);
+ writel(edmac->dma_cfg.port & 0xf, edmac->regs + M2P_PPALLOC);

control = M2P_CONTROL_CH_ERROR_INT | M2P_CONTROL_ICE
| M2P_CONTROL_ENABLE;
@@ -458,16 +473,15 @@ static int m2p_hw_interrupt(struct ep93xx_dma_chan *edmac)

static int m2m_hw_setup(struct ep93xx_dma_chan *edmac)
{
- const struct ep93xx_dma_data *data = edmac->chan.private;
u32 control = 0;

- if (!data) {
+ if (edmac->dma_cfg.dir == DMA_MEM_TO_MEM) {
/* This is memcpy channel, nothing to configure */
writel(control, edmac->regs + M2M_CONTROL);
return 0;
}

- switch (data->port) {
+ switch (edmac->dma_cfg.port) {
case EP93XX_DMA_SSP:
/*
* This was found via experimenting - anything less than 5
@@ -477,7 +491,7 @@ static int m2m_hw_setup(struct ep93xx_dma_chan *edmac)
control = (5 << M2M_CONTROL_PWSC_SHIFT);
control |= M2M_CONTROL_NO_HDSK;

- if (data->direction == DMA_MEM_TO_DEV) {
+ if (edmac->dma_cfg.dir == DMA_MEM_TO_DEV) {
control |= M2M_CONTROL_DAH;
control |= M2M_CONTROL_TM_TX;
control |= M2M_CONTROL_RSS_SSPTX;
@@ -493,7 +507,7 @@ static int m2m_hw_setup(struct ep93xx_dma_chan *edmac)
* This IDE part is totally untested. Values below are taken
* from the EP93xx Users's Guide and might not be correct.
*/
- if (data->direction == DMA_MEM_TO_DEV) {
+ if (edmac->dma_cfg.dir == DMA_MEM_TO_DEV) {
/* Worst case from the UG */
control = (3 << M2M_CONTROL_PWSC_SHIFT);
control |= M2M_CONTROL_DAH;
@@ -548,7 +562,6 @@ static void m2m_fill_desc(struct ep93xx_dma_chan *edmac)

static void m2m_hw_submit(struct ep93xx_dma_chan *edmac)
{
- struct ep93xx_dma_data *data = edmac->chan.private;
u32 control = readl(edmac->regs + M2M_CONTROL);

/*
@@ -574,7 +587,7 @@ static void m2m_hw_submit(struct ep93xx_dma_chan *edmac)
control |= M2M_CONTROL_ENABLE;
writel(control, edmac->regs + M2M_CONTROL);

- if (!data) {
+ if (edmac->dma_cfg.dir == DMA_MEM_TO_MEM) {
/*
* For memcpy channels the software trigger must be asserted
* in order to start the memcpy operation.
@@ -636,7 +649,7 @@ static int m2m_hw_interrupt(struct ep93xx_dma_chan *edmac)
*/
if (ep93xx_dma_advance_active(edmac)) {
m2m_fill_desc(edmac);
- if (done && !edmac->chan.private) {
+ if (done && edmac->dma_cfg.dir == DMA_MEM_TO_MEM) {
/* Software trigger for memcpy channel */
control = readl(edmac->regs + M2M_CONTROL);
control |= M2M_CONTROL_START;
@@ -867,25 +880,22 @@ static dma_cookie_t ep93xx_dma_tx_submit(struct dma_async_tx_descriptor *tx)
static int ep93xx_dma_alloc_chan_resources(struct dma_chan *chan)
{
struct ep93xx_dma_chan *edmac = to_ep93xx_dma_chan(chan);
- struct ep93xx_dma_data *data = chan->private;
const char *name = dma_chan_name(chan);
int ret, i;

/* Sanity check the channel parameters */
if (!edmac->edma->m2m) {
- if (!data)
+ if (edmac->dma_cfg.port < EP93XX_DMA_I2S1 ||
+ edmac->dma_cfg.port > EP93XX_DMA_IRDA)
return -EINVAL;
- if (data->port < EP93XX_DMA_I2S1 ||
- data->port > EP93XX_DMA_IRDA)
- return -EINVAL;
- if (data->direction != ep93xx_dma_chan_direction(chan))
+ if (edmac->dma_cfg.dir != ep93xx_dma_chan_direction(chan))
return -EINVAL;
} else {
- if (data) {
- switch (data->port) {
+ if (edmac->dma_cfg.dir != DMA_MEM_TO_MEM) {
+ switch (edmac->dma_cfg.port) {
case EP93XX_DMA_SSP:
case EP93XX_DMA_IDE:
- if (!is_slave_direction(data->direction))
+ if (!is_slave_direction(edmac->dma_cfg.dir))
return -EINVAL;
break;
default:
@@ -894,9 +904,6 @@ static int ep93xx_dma_alloc_chan_resources(struct dma_chan *chan)
}
}

- if (data && data->name)
- name = data->name;
-
ret = clk_prepare_enable(edmac->clk);
if (ret)
return ret;
@@ -1315,36 +1322,53 @@ static void ep93xx_dma_issue_pending(struct dma_chan *chan)
ep93xx_dma_advance_work(to_ep93xx_dma_chan(chan));
}

-static int __init ep93xx_dma_probe(struct platform_device *pdev)
+static struct ep93xx_dma_engine *ep93xx_dma_of_probe(struct platform_device *pdev)
{
- struct ep93xx_dma_platform_data *pdata = dev_get_platdata(&pdev->dev);
+ const struct ep93xx_edma_data *data;
+ struct device *dev = &pdev->dev;
struct ep93xx_dma_engine *edma;
struct dma_device *dma_dev;
- int ret, i;
+ char dma_clk_name[5];
+ int i;

- edma = kzalloc(struct_size(edma, channels, pdata->num_channels), GFP_KERNEL);
+ data = device_get_match_data(dev);
+ if (!data)
+ return ERR_PTR(dev_err_probe(dev, -ENODEV, "No device match found\n"));
+
+ edma = devm_kzalloc(dev, struct_size(edma, channels, data->num_channels),
+ GFP_KERNEL);
if (!edma)
- return -ENOMEM;
+ return ERR_PTR(-ENOMEM);

+ edma->m2m = data->id;
+ edma->num_channels = data->num_channels;
dma_dev = &edma->dma_dev;
- edma->m2m = platform_get_device_id(pdev)->driver_data;
- edma->num_channels = pdata->num_channels;

INIT_LIST_HEAD(&dma_dev->channels);
- for (i = 0; i < pdata->num_channels; i++) {
- const struct ep93xx_dma_chan_data *cdata = &pdata->channels[i];
+ for (i = 0; i < edma->num_channels; i++) {
struct ep93xx_dma_chan *edmac = &edma->channels[i];

edmac->chan.device = dma_dev;
- edmac->regs = cdata->base;
- edmac->irq = cdata->irq;
+ edmac->regs = devm_platform_ioremap_resource(pdev, i);
+ if (IS_ERR(edmac->regs))
+ return edmac->regs;
+
+ edmac->irq = fwnode_irq_get(dev_fwnode(dev), i);
+ if (edmac->irq < 0)
+ return ERR_PTR(edmac->irq);
+
edmac->edma = edma;

- edmac->clk = clk_get(NULL, cdata->name);
+ if (edma->m2m)
+ sprintf(dma_clk_name, "m2m%u", i);
+ else
+ sprintf(dma_clk_name, "m2p%u", i);
+
+ edmac->clk = devm_clk_get(dev, dma_clk_name);
if (IS_ERR(edmac->clk)) {
- dev_warn(&pdev->dev, "failed to get clock for %s\n",
- cdata->name);
- continue;
+ dev_err_probe(dev, PTR_ERR(edmac->clk),
+ "no %s clock found\n", dma_clk_name);
+ return ERR_CAST(edmac->clk);
}

spin_lock_init(&edmac->lock);
@@ -1357,6 +1381,90 @@ static int __init ep93xx_dma_probe(struct platform_device *pdev)
&dma_dev->channels);
}

+ return edma;
+}
+
+static bool ep93xx_m2p_dma_filter(struct dma_chan *chan, void *filter_param)
+{
+ struct ep93xx_dma_chan *echan = to_ep93xx_dma_chan(chan);
+ struct ep93xx_dma_chan_cfg *cfg = filter_param;
+
+ if (cfg->dir != ep93xx_dma_chan_direction(chan))
+ return false;
+
+ echan->dma_cfg = *cfg;
+ return true;
+}
+
+static struct dma_chan *ep93xx_m2p_dma_of_xlate(struct of_phandle_args *dma_spec,
+ struct of_dma *ofdma)
+{
+ struct ep93xx_dma_engine *edma = ofdma->of_dma_data;
+ dma_cap_mask_t mask = edma->dma_dev.cap_mask;
+ struct ep93xx_dma_chan_cfg dma_cfg;
+ u8 port = dma_spec->args[0];
+ u8 direction = dma_spec->args[1];
+
+ if (port > EP93XX_DMA_IRDA)
+ return NULL;
+
+ if (!is_slave_direction(direction))
+ return NULL;
+
+ dma_cfg.port = port;
+ dma_cfg.dir = direction;
+
+ return __dma_request_channel(&mask, ep93xx_m2p_dma_filter, &dma_cfg, ofdma->of_node);
+}
+
+static bool ep93xx_m2m_dma_filter(struct dma_chan *chan, void *filter_param)
+{
+ struct ep93xx_dma_chan *echan = to_ep93xx_dma_chan(chan);
+ struct ep93xx_dma_chan_cfg *cfg = filter_param;
+
+ echan->dma_cfg = *cfg;
+
+ return true;
+}
+
+static struct dma_chan *ep93xx_m2m_dma_of_xlate(struct of_phandle_args *dma_spec,
+ struct of_dma *ofdma)
+{
+ struct ep93xx_dma_engine *edma = ofdma->of_dma_data;
+ dma_cap_mask_t mask = edma->dma_dev.cap_mask;
+ struct ep93xx_dma_chan_cfg dma_cfg;
+ u8 port = dma_spec->args[0];
+ u8 direction = dma_spec->args[1];
+
+ if (!is_slave_direction(direction))
+ return NULL;
+
+ switch (port) {
+ case EP93XX_DMA_SSP:
+ case EP93XX_DMA_IDE:
+ break;
+ default:
+ return NULL;
+ }
+
+ dma_cfg.port = port;
+ dma_cfg.dir = direction;
+
+ return __dma_request_channel(&mask, ep93xx_m2m_dma_filter, &dma_cfg, ofdma->of_node);
+}
+
+static int ep93xx_dma_probe(struct platform_device *pdev)
+{
+ struct ep93xx_dma_engine *edma;
+ struct dma_device *dma_dev;
+ int ret;
+
+ edma = ep93xx_dma_of_probe(pdev);
+ if (!edma)
+ return PTR_ERR(edma);
+
+ dma_dev = &edma->dma_dev;
+
dma_cap_zero(dma_dev->cap_mask);
dma_cap_set(DMA_SLAVE, dma_dev->cap_mask);
dma_cap_set(DMA_CYCLIC, dma_dev->cap_mask);
@@ -1393,21 +1501,46 @@ static int __init ep93xx_dma_probe(struct platform_device *pdev)
}

ret = dma_async_device_register(dma_dev);
- if (unlikely(ret)) {
- for (i = 0; i < edma->num_channels; i++) {
- struct ep93xx_dma_chan *edmac = &edma->channels[i];
- if (!IS_ERR_OR_NULL(edmac->clk))
- clk_put(edmac->clk);
- }
- kfree(edma);
+ if (ret)
+ return ret;
+
+ if (edma->m2m) {
+ ret = of_dma_controller_register(pdev->dev.of_node, ep93xx_m2m_dma_of_xlate,
+ edma);
} else {
- dev_info(dma_dev->dev, "EP93xx M2%s DMA ready\n",
- edma->m2m ? "M" : "P");
+ ret = of_dma_controller_register(pdev->dev.of_node, ep93xx_m2p_dma_of_xlate,
+ edma);
}
+ if (ret)
+ goto err_dma_unregister;
+
+ dev_info(dma_dev->dev, "EP93xx M2%s DMA ready\n", edma->m2m ? "M" : "P");
+
+ return 0;
+
+err_dma_unregister:
+ dma_async_device_unregister(dma_dev);

return ret;
}

+static const struct ep93xx_edma_data edma_m2p = {
+ .id = M2P_DMA,
+ .num_channels = 10,
+};
+
+static const struct ep93xx_edma_data edma_m2m = {
+ .id = M2M_DMA,
+ .num_channels = 2,
+};
+
+static const struct of_device_id ep93xx_dma_of_ids[] = {
+ { .compatible = "cirrus,ep9301-dma-m2p", .data = &edma_m2p },
+ { .compatible = "cirrus,ep9301-dma-m2m", .data = &edma_m2m },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, ep93xx_dma_of_ids);
+
static const struct platform_device_id ep93xx_dma_driver_ids[] = {
{ "ep93xx-dma-m2p", 0 },
{ "ep93xx-dma-m2m", 1 },
@@ -1417,15 +1550,13 @@ static const struct platform_device_id ep93xx_dma_driver_ids[] = {
static struct platform_driver ep93xx_dma_driver = {
.driver = {
.name = "ep93xx-dma",
+ .of_match_table = ep93xx_dma_of_ids,
},
.id_table = ep93xx_dma_driver_ids,
+ .probe = ep93xx_dma_probe,
};

-static int __init ep93xx_dma_module_init(void)
-{
- return platform_driver_probe(&ep93xx_dma_driver, ep93xx_dma_probe);
-}
-subsys_initcall(ep93xx_dma_module_init);
+module_platform_driver(ep93xx_dma_driver);

MODULE_AUTHOR("Mika Westerberg <mika.westerberg@iki.fi>");
MODULE_DESCRIPTION("EP93xx DMA driver");
diff --git a/include/linux/platform_data/dma-ep93xx.h b/include/linux/platform_data/dma-ep93xx.h
index eb9805bb3fe8..9ec5cdd5a1eb 100644
--- a/include/linux/platform_data/dma-ep93xx.h
+++ b/include/linux/platform_data/dma-ep93xx.h
@@ -3,8 +3,11 @@
#define __ASM_ARCH_DMA_H

#include <linux/types.h>
+#include <linux/device.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
+#include <linux/property.h>
+#include <linux/string.h>

/*
* M2P channels.
@@ -70,6 +73,9 @@ struct ep93xx_dma_platform_data {

static inline bool ep93xx_dma_chan_is_m2p(struct dma_chan *chan)
{
+ if (device_is_compatible(chan->device->dev, "cirrus,ep9301-dma-m2p"))
+ return true;
+
return !strcmp(dev_name(chan->device->dev), "ep93xx-dma-m2p");
}

--
2.41.0