Add the chipselect array and cur_cs properties to pl022 main structure
Add a wrapper function to decide if the cs should be controlled by the
cs_control callback or the chipselect gpio
Populate chipselect property from cs-gpios
Populate master->dev.of_node, so the spi bus can find child spi
devices and register them
At pl022 setup, fill chip_data structure from dt nodes, if not provided
by platform.
Signed-off-by: Alexandre Pereira da Silva <[email protected]>
Acked-by: Roland Stigge <[email protected]>
---
Applies to v3.6-rc1
Changes since v3:
* Proper use of IS_ENABLED
Changes since v2:
* Use IS_ENABLED instead of #ifdef
* Remove bogus const change
Changes since v1:
* return EPROBE_DEFFER if gpios are not initialized yet
Thanks Thierry Reding for reviewing and improvements suggestions
.../devicetree/bindings/spi/spi_pl022.txt | 15 +++
drivers/spi/spi-pl022.c | 114 ++++++++++++++++----
2 files changed, 110 insertions(+), 19 deletions(-)
diff --git a/Documentation/devicetree/bindings/spi/spi_pl022.txt b/Documentation/devicetree/bindings/spi/spi_pl022.txt
index 306ec3f..b089ec7 100644
--- a/Documentation/devicetree/bindings/spi/spi_pl022.txt
+++ b/Documentation/devicetree/bindings/spi/spi_pl022.txt
@@ -6,7 +6,22 @@ Required properties:
- interrupts : Should contain SPI controller interrupt
Optional properties:
+- pl022,num-chipselects : total number of chipselects
- cs-gpios : should specify GPIOs used for chipselects.
The gpios will be referred to as reg = <index> in the SPI child nodes.
If unspecified, a single SPI device without a chip select can be used.
+SPI slave nodes must be children of the SPI master node and can
+contain the following properties.
+See include/linux/amba/pl022.h for more details
+
+- pl022,hierarchy : master or slave interface
+- pl022,interface : interface type
+- pl022,slave-tx-disable : disconnect tx line in slave mode
+- pl022,com-mode : polling, interrupt or dma
+- pl022,rx-level-trig : Rx FIFO watermark level
+- pl022,tx-level-trig : Tx FIFO watermark level
+- pl022,ctrl-len : Microwire interface: Control length
+- pl022,wait-state : Microwire interface: Wait state
+- pl022,duplex : Microwire interface: Full/Half duplex
+
diff --git a/drivers/spi/spi-pl022.c b/drivers/spi/spi-pl022.c
index 400ae21..d8d7d21 100644
--- a/drivers/spi/spi-pl022.c
+++ b/drivers/spi/spi-pl022.c
@@ -40,6 +40,8 @@
#include <linux/dma-mapping.h>
#include <linux/scatterlist.h>
#include <linux/pm_runtime.h>
+#include <linux/gpio.h>
+#include <linux/of_gpio.h>
/*
* This macro is used to define some register default values.
@@ -389,6 +391,8 @@ struct pl022 {
char *dummypage;
bool dma_running;
#endif
+ int cur_cs;
+ int chipselect[0];
};
/**
@@ -433,6 +437,14 @@ static void null_cs_control(u32 command)
pr_debug("pl022: dummy chip select control, CS=0x%x\n", command);
}
+static void pl022_cs_control(struct pl022 *pl022, u32 command)
+{
+ if (gpio_is_valid(pl022->cur_cs))
+ gpio_set_value(pl022->cur_cs, command);
+ else
+ pl022->cur_chip->cs_control(command);
+}
+
/**
* giveback - current spi_message is over, schedule next message and call
* callback of this message. Assumes that caller already
@@ -479,7 +491,7 @@ static void giveback(struct pl022 *pl022)
if (next_msg && next_msg->spi != pl022->cur_msg->spi)
next_msg = NULL;
if (!next_msg || pl022->cur_msg->state == STATE_ERROR)
- pl022->cur_chip->cs_control(SSP_CHIP_DESELECT);
+ pl022_cs_control(pl022, SSP_CHIP_DESELECT);
else
pl022->next_msg_cs_active = true;
@@ -813,8 +825,7 @@ static void dma_callback(void *data)
/* Update total bytes transferred */
msg->actual_length += pl022->cur_transfer->len;
if (pl022->cur_transfer->cs_change)
- pl022->cur_chip->
- cs_control(SSP_CHIP_DESELECT);
+ pl022_cs_control(pl022, SSP_CHIP_DESELECT);
/* Move to next transfer */
msg->state = next_transfer(pl022);
@@ -1247,8 +1258,7 @@ static irqreturn_t pl022_interrupt_handler(int irq, void *dev_id)
/* Update total bytes transferred */
msg->actual_length += pl022->cur_transfer->len;
if (pl022->cur_transfer->cs_change)
- pl022->cur_chip->
- cs_control(SSP_CHIP_DESELECT);
+ pl022_cs_control(pl022, SSP_CHIP_DESELECT);
/* Move to next transfer */
msg->state = next_transfer(pl022);
tasklet_schedule(&pl022->pump_transfers);
@@ -1333,7 +1343,7 @@ static void pump_transfers(unsigned long data)
/* Reselect chip select only if cs_change was requested */
if (previous->cs_change)
- pl022->cur_chip->cs_control(SSP_CHIP_SELECT);
+ pl022_cs_control(pl022, SSP_CHIP_SELECT);
} else {
/* STATE_START */
message->state = STATE_RUNNING;
@@ -1372,7 +1382,7 @@ static void do_interrupt_dma_transfer(struct pl022 *pl022)
/* Enable target chip, if not already active */
if (!pl022->next_msg_cs_active)
- pl022->cur_chip->cs_control(SSP_CHIP_SELECT);
+ pl022_cs_control(pl022, SSP_CHIP_SELECT);
if (set_up_next_transfer(pl022, pl022->cur_transfer)) {
/* Error path */
@@ -1424,12 +1434,12 @@ static void do_polling_transfer(struct pl022 *pl022)
if (previous->delay_usecs)
udelay(previous->delay_usecs);
if (previous->cs_change)
- pl022->cur_chip->cs_control(SSP_CHIP_SELECT);
+ pl022_cs_control(pl022, SSP_CHIP_SELECT);
} else {
/* STATE_START */
message->state = STATE_RUNNING;
if (!pl022->next_msg_cs_active)
- pl022->cur_chip->cs_control(SSP_CHIP_SELECT);
+ pl022_cs_control(pl022, SSP_CHIP_SELECT);
}
/* Configuration Changing Per Transfer */
@@ -1461,7 +1471,7 @@ static void do_polling_transfer(struct pl022 *pl022)
/* Update total byte transferred */
message->actual_length += pl022->cur_transfer->len;
if (pl022->cur_transfer->cs_change)
- pl022->cur_chip->cs_control(SSP_CHIP_DESELECT);
+ pl022_cs_control(pl022, SSP_CHIP_DESELECT);
/* Move to next transfer */
message->state = next_transfer(pl022);
}
@@ -1490,6 +1500,7 @@ static int pl022_transfer_one_message(struct spi_master *master,
/* Setup the SPI using the per chip configuration */
pl022->cur_chip = spi_get_ctldata(msg->spi);
+ pl022->cur_cs = pl022->chipselect[msg->spi->chip_select];
restore_state(pl022);
flush(pl022);
@@ -1761,12 +1772,14 @@ static const struct pl022_config_chip pl022_default_chip_info = {
static int pl022_setup(struct spi_device *spi)
{
struct pl022_config_chip const *chip_info;
+ struct pl022_config_chip chip_info_dt;
struct chip_data *chip;
struct ssp_clock_params clk_freq = { .cpsdvsr = 0, .scr = 0};
int status = 0;
struct pl022 *pl022 = spi_master_get_devdata(spi->master);
unsigned int bits = spi->bits_per_word;
u32 tmp;
+ struct device_node *np = spi->dev.of_node;
if (!spi->max_speed_hz)
return -EINVAL;
@@ -1789,10 +1802,36 @@ static int pl022_setup(struct spi_device *spi)
chip_info = spi->controller_data;
if (chip_info == NULL) {
- chip_info = &pl022_default_chip_info;
- /* spi_board_info.controller_data not is supplied */
- dev_dbg(&spi->dev,
- "using default controller_data settings\n");
+ if (np) {
+ chip_info_dt = pl022_default_chip_info;
+
+ of_property_read_u32(np, "pl022,hierarchy",
+ &chip_info_dt.hierarchy);
+ of_property_read_u32(np, "pl022,interface",
+ &chip_info_dt.iface);
+ chip_info_dt.slave_tx_disable =
+ of_property_read_bool(np,
+ "pl022,slave-tx-disable");
+ of_property_read_u32(np, "pl022,com-mode",
+ &chip_info_dt.com_mode);
+ of_property_read_u32(np, "pl022,rx-level-trig",
+ &chip_info_dt.rx_lev_trig);
+ of_property_read_u32(np, "pl022,tx-level-trig",
+ &chip_info_dt.tx_lev_trig);
+ of_property_read_u32(np, "pl022,ctrl-len",
+ &chip_info_dt.ctrl_len);
+ of_property_read_u32(np, "pl022,wait-state",
+ &chip_info_dt.wait_state);
+ of_property_read_u32(np, "pl022,duplex",
+ &chip_info_dt.duplex);
+
+ chip_info = &chip_info_dt;
+ } else {
+ chip_info = &pl022_default_chip_info;
+ /* spi_board_info.controller_data not is supplied */
+ dev_dbg(&spi->dev,
+ "using default controller_data settings\n");
+ }
} else
dev_dbg(&spi->dev,
"using user supplied controller_data settings\n");
@@ -1835,8 +1874,9 @@ static int pl022_setup(struct spi_device *spi)
chip->xfer_type = chip_info->com_mode;
if (!chip_info->cs_control) {
chip->cs_control = null_cs_control;
- dev_warn(&spi->dev,
- "chip select function is NULL for this chip\n");
+ if (!gpio_is_valid(pl022->chipselect[spi->chip_select]))
+ dev_warn(&spi->dev,
+ "chip select function is NULL for this chip\n");
} else
chip->cs_control = chip_info->cs_control;
@@ -1988,7 +2028,8 @@ pl022_probe(struct amba_device *adev, const struct amba_id *id)
struct pl022_ssp_controller *platform_info = adev->dev.platform_data;
struct spi_master *master;
struct pl022 *pl022 = NULL; /*Data for this driver */
- int status = 0;
+ struct device_node *np = adev->dev.of_node;
+ int status = 0, i, num_cs;
dev_info(&adev->dev,
"ARM PL022 driver, device ID: 0x%08x\n", adev->periphid);
@@ -1998,8 +2039,14 @@ pl022_probe(struct amba_device *adev, const struct amba_id *id)
goto err_no_pdata;
}
+ num_cs = platform_info->num_chipselect;
+ if (IS_ENABLED(CONFIG_OF))
+ of_property_read_u32(np, "pl022,num-chipselects", &num_cs);
+
+
/* Allocate master with space for data */
- master = spi_alloc_master(dev, sizeof(struct pl022));
+ master = spi_alloc_master(dev,
+ sizeof(struct pl022) + sizeof(int) * num_cs);
if (master == NULL) {
dev_err(&adev->dev, "probe - cannot alloc SPI master\n");
status = -ENOMEM;
@@ -2017,13 +2064,41 @@ pl022_probe(struct amba_device *adev, const struct amba_id *id)
* on this board
*/
master->bus_num = platform_info->bus_id;
- master->num_chipselect = platform_info->num_chipselect;
+ master->num_chipselect = num_cs;
master->cleanup = pl022_cleanup;
master->setup = pl022_setup;
master->prepare_transfer_hardware = pl022_prepare_transfer_hardware;
master->transfer_one_message = pl022_transfer_one_message;
master->unprepare_transfer_hardware = pl022_unprepare_transfer_hardware;
master->rt = platform_info->rt;
+ master->dev.of_node = dev->of_node;
+
+ if (IS_ENABLED(CONFIG_OF)) {
+ for (i = 0; i < num_cs; i++) {
+ int cs_gpio = of_get_named_gpio(np, "cs-gpios", i);
+
+ if (cs_gpio == -EPROBE_DEFER) {
+ status = -EPROBE_DEFER;
+ goto err_no_gpio;
+ }
+
+ pl022->chipselect[i] = cs_gpio;
+
+ if (gpio_is_valid(cs_gpio)) {
+ if (gpio_request(cs_gpio, "ssp-pl022"))
+ dev_err(&adev->dev,
+ "could not request %d gpio\n",
+ cs_gpio);
+ else if (gpio_direction_output(cs_gpio, 1))
+ dev_err(&adev->dev,
+ "could set gpio %d as output\n",
+ cs_gpio);
+ }
+ }
+ } else {
+ for (i = 0; i < num_cs; i++)
+ pl022->chipselect[i] = -EINVAL;
+ }
/*
* Supports mode 0-3, loopback, and active low CS. Transfers are
@@ -2130,6 +2205,7 @@ pl022_probe(struct amba_device *adev, const struct amba_id *id)
err_no_ioremap:
amba_release_regions(adev);
err_no_ioregion:
+ err_no_gpio:
spi_master_put(master);
err_no_master:
err_no_pdata:
--
1.7.10
Hi all,
On 08/20/2012 01:39 PM, Alexandre Pereira da Silva wrote:
> Add the chipselect array and cur_cs properties to pl022 main structure
>
> Add a wrapper function to decide if the cs should be controlled by the
> cs_control callback or the chipselect gpio
>
> Populate chipselect property from cs-gpios
>
> Populate master->dev.of_node, so the spi bus can find child spi
> devices and register them
>
> At pl022 setup, fill chip_data structure from dt nodes, if not provided
> by platform.
>
> Signed-off-by: Alexandre Pereira da Silva <[email protected]>
> Acked-by: Roland Stigge <[email protected]>
We somehow missed 3.6 with this one. Would be nice to have it in 3.7 now
since it's useful for mach-lpc32xx when it's available.
If there are any open issues, I can assist Alexandre on this patch.
Thanks in advance,
Roland
On 08/20/2012 07:58 AM, Roland Stigge wrote:
> Hi all,
>
> On 08/20/2012 01:39 PM, Alexandre Pereira da Silva wrote:
>> Add the chipselect array and cur_cs properties to pl022 main structure
>>
>> Add a wrapper function to decide if the cs should be controlled by the
>> cs_control callback or the chipselect gpio
>>
>> Populate chipselect property from cs-gpios
>>
>> Populate master->dev.of_node, so the spi bus can find child spi
>> devices and register them
>>
>> At pl022 setup, fill chip_data structure from dt nodes, if not provided
>> by platform.
>>
>> Signed-off-by: Alexandre Pereira da Silva <[email protected]>
>> Acked-by: Roland Stigge <[email protected]>
>
> We somehow missed 3.6 with this one. Would be nice to have it in 3.7 now
> since it's useful for mach-lpc32xx when it's available.
Mark Brown is handling SPI right now for Grant, so please send it to
him. I have some comments on the patch though.
Rob
>
> If there are any open issues, I can assist Alexandre on this patch.
>
> Thanks in advance,
>
> Roland
>
On 08/20/2012 06:39 AM, Alexandre Pereira da Silva wrote:
> Add the chipselect array and cur_cs properties to pl022 main structure
>
> Add a wrapper function to decide if the cs should be controlled by the
> cs_control callback or the chipselect gpio
>
> Populate chipselect property from cs-gpios
>
> Populate master->dev.of_node, so the spi bus can find child spi
> devices and register them
>
> At pl022 setup, fill chip_data structure from dt nodes, if not provided
> by platform.
>
> Signed-off-by: Alexandre Pereira da Silva <[email protected]>
> Acked-by: Roland Stigge <[email protected]>
> ---
> Applies to v3.6-rc1
>
> Changes since v3:
> * Proper use of IS_ENABLED
>
> Changes since v2:
> * Use IS_ENABLED instead of #ifdef
> * Remove bogus const change
>
> Changes since v1:
> * return EPROBE_DEFFER if gpios are not initialized yet
>
> Thanks Thierry Reding for reviewing and improvements suggestions
>
> .../devicetree/bindings/spi/spi_pl022.txt | 15 +++
> drivers/spi/spi-pl022.c | 114 ++++++++++++++++----
> 2 files changed, 110 insertions(+), 19 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/spi/spi_pl022.txt b/Documentation/devicetree/bindings/spi/spi_pl022.txt
> index 306ec3f..b089ec7 100644
> --- a/Documentation/devicetree/bindings/spi/spi_pl022.txt
> +++ b/Documentation/devicetree/bindings/spi/spi_pl022.txt
> @@ -6,7 +6,22 @@ Required properties:
> - interrupts : Should contain SPI controller interrupt
>
> Optional properties:
> +- pl022,num-chipselects : total number of chipselects
We have this for other spi controllers too. Define a generic property.
> - cs-gpios : should specify GPIOs used for chipselects.
> The gpios will be referred to as reg = <index> in the SPI child nodes.
> If unspecified, a single SPI device without a chip select can be used.
>
> +SPI slave nodes must be children of the SPI master node and can
> +contain the following properties.
> +See include/linux/amba/pl022.h for more details
DT binding is independent of Linux, so you should not refer to Linux docs.
> +
> +- pl022,hierarchy : master or slave interface
Is attaching a master and using the pl022 as a slave really a supported
use case? The DT spi bindings are really designed for a master node with
N slave nodes. So there is more general question of how to describe a
spi controller as a slave. It's not really one I care to answer as the
Linux spi framework isn't designed to act as a slave.
> +- pl022,interface : interface type
And valid values are?
> +- pl022,slave-tx-disable : disconnect tx line in slave mode
> +- pl022,com-mode : polling, interrupt or dma
> +- pl022,rx-level-trig : Rx FIFO watermark level
> +- pl022,tx-level-trig : Tx FIFO watermark level
> +- pl022,ctrl-len : Microwire interface: Control length
> +- pl022,wait-state : Microwire interface: Wait state
> +- pl022,duplex : Microwire interface: Full/Half duplex
Most of these properties aren't used anywhere in the kernel other than
u300 and I'm not sure what to purpose of dummy_chip_info is. Perhaps
Linus has some input? I think either they can be decided by the spi
controller (com-mode, fifo watermark) or should be standard properties
(microwire settings). I would argue they should be removed if the spi
framework doesn't have support in a standard way.
> +
> diff --git a/drivers/spi/spi-pl022.c b/drivers/spi/spi-pl022.c
> index 400ae21..d8d7d21 100644
> --- a/drivers/spi/spi-pl022.c
> +++ b/drivers/spi/spi-pl022.c
> @@ -40,6 +40,8 @@
> #include <linux/dma-mapping.h>
> #include <linux/scatterlist.h>
> #include <linux/pm_runtime.h>
> +#include <linux/gpio.h>
> +#include <linux/of_gpio.h>
>
> /*
> * This macro is used to define some register default values.
> @@ -389,6 +391,8 @@ struct pl022 {
> char *dummypage;
> bool dma_running;
> #endif
> + int cur_cs;
> + int chipselect[0];
> };
>
> /**
> @@ -433,6 +437,14 @@ static void null_cs_control(u32 command)
> pr_debug("pl022: dummy chip select control, CS=0x%x\n", command);
> }
>
> +static void pl022_cs_control(struct pl022 *pl022, u32 command)
> +{
> + if (gpio_is_valid(pl022->cur_cs))
> + gpio_set_value(pl022->cur_cs, command);
> + else
> + pl022->cur_chip->cs_control(command);
> +}
> +
> /**
> * giveback - current spi_message is over, schedule next message and call
> * callback of this message. Assumes that caller already
> @@ -479,7 +491,7 @@ static void giveback(struct pl022 *pl022)
> if (next_msg && next_msg->spi != pl022->cur_msg->spi)
> next_msg = NULL;
> if (!next_msg || pl022->cur_msg->state == STATE_ERROR)
> - pl022->cur_chip->cs_control(SSP_CHIP_DESELECT);
> + pl022_cs_control(pl022, SSP_CHIP_DESELECT);
> else
> pl022->next_msg_cs_active = true;
>
> @@ -813,8 +825,7 @@ static void dma_callback(void *data)
> /* Update total bytes transferred */
> msg->actual_length += pl022->cur_transfer->len;
> if (pl022->cur_transfer->cs_change)
> - pl022->cur_chip->
> - cs_control(SSP_CHIP_DESELECT);
> + pl022_cs_control(pl022, SSP_CHIP_DESELECT);
>
> /* Move to next transfer */
> msg->state = next_transfer(pl022);
> @@ -1247,8 +1258,7 @@ static irqreturn_t pl022_interrupt_handler(int irq, void *dev_id)
> /* Update total bytes transferred */
> msg->actual_length += pl022->cur_transfer->len;
> if (pl022->cur_transfer->cs_change)
> - pl022->cur_chip->
> - cs_control(SSP_CHIP_DESELECT);
> + pl022_cs_control(pl022, SSP_CHIP_DESELECT);
> /* Move to next transfer */
> msg->state = next_transfer(pl022);
> tasklet_schedule(&pl022->pump_transfers);
> @@ -1333,7 +1343,7 @@ static void pump_transfers(unsigned long data)
>
> /* Reselect chip select only if cs_change was requested */
> if (previous->cs_change)
> - pl022->cur_chip->cs_control(SSP_CHIP_SELECT);
> + pl022_cs_control(pl022, SSP_CHIP_SELECT);
> } else {
> /* STATE_START */
> message->state = STATE_RUNNING;
> @@ -1372,7 +1382,7 @@ static void do_interrupt_dma_transfer(struct pl022 *pl022)
>
> /* Enable target chip, if not already active */
> if (!pl022->next_msg_cs_active)
> - pl022->cur_chip->cs_control(SSP_CHIP_SELECT);
> + pl022_cs_control(pl022, SSP_CHIP_SELECT);
>
> if (set_up_next_transfer(pl022, pl022->cur_transfer)) {
> /* Error path */
> @@ -1424,12 +1434,12 @@ static void do_polling_transfer(struct pl022 *pl022)
> if (previous->delay_usecs)
> udelay(previous->delay_usecs);
> if (previous->cs_change)
> - pl022->cur_chip->cs_control(SSP_CHIP_SELECT);
> + pl022_cs_control(pl022, SSP_CHIP_SELECT);
> } else {
> /* STATE_START */
> message->state = STATE_RUNNING;
> if (!pl022->next_msg_cs_active)
> - pl022->cur_chip->cs_control(SSP_CHIP_SELECT);
> + pl022_cs_control(pl022, SSP_CHIP_SELECT);
> }
>
> /* Configuration Changing Per Transfer */
> @@ -1461,7 +1471,7 @@ static void do_polling_transfer(struct pl022 *pl022)
> /* Update total byte transferred */
> message->actual_length += pl022->cur_transfer->len;
> if (pl022->cur_transfer->cs_change)
> - pl022->cur_chip->cs_control(SSP_CHIP_DESELECT);
> + pl022_cs_control(pl022, SSP_CHIP_DESELECT);
> /* Move to next transfer */
> message->state = next_transfer(pl022);
> }
> @@ -1490,6 +1500,7 @@ static int pl022_transfer_one_message(struct spi_master *master,
>
> /* Setup the SPI using the per chip configuration */
> pl022->cur_chip = spi_get_ctldata(msg->spi);
> + pl022->cur_cs = pl022->chipselect[msg->spi->chip_select];
>
> restore_state(pl022);
> flush(pl022);
> @@ -1761,12 +1772,14 @@ static const struct pl022_config_chip pl022_default_chip_info = {
> static int pl022_setup(struct spi_device *spi)
> {
> struct pl022_config_chip const *chip_info;
> + struct pl022_config_chip chip_info_dt;
> struct chip_data *chip;
> struct ssp_clock_params clk_freq = { .cpsdvsr = 0, .scr = 0};
> int status = 0;
> struct pl022 *pl022 = spi_master_get_devdata(spi->master);
> unsigned int bits = spi->bits_per_word;
> u32 tmp;
> + struct device_node *np = spi->dev.of_node;
>
> if (!spi->max_speed_hz)
> return -EINVAL;
> @@ -1789,10 +1802,36 @@ static int pl022_setup(struct spi_device *spi)
> chip_info = spi->controller_data;
>
> if (chip_info == NULL) {
> - chip_info = &pl022_default_chip_info;
> - /* spi_board_info.controller_data not is supplied */
> - dev_dbg(&spi->dev,
> - "using default controller_data settings\n");
> + if (np) {
> + chip_info_dt = pl022_default_chip_info;
> +
> + of_property_read_u32(np, "pl022,hierarchy",
> + &chip_info_dt.hierarchy);
> + of_property_read_u32(np, "pl022,interface",
> + &chip_info_dt.iface);
> + chip_info_dt.slave_tx_disable =
> + of_property_read_bool(np,
> + "pl022,slave-tx-disable");
> + of_property_read_u32(np, "pl022,com-mode",
> + &chip_info_dt.com_mode);
> + of_property_read_u32(np, "pl022,rx-level-trig",
> + &chip_info_dt.rx_lev_trig);
> + of_property_read_u32(np, "pl022,tx-level-trig",
> + &chip_info_dt.tx_lev_trig);
> + of_property_read_u32(np, "pl022,ctrl-len",
> + &chip_info_dt.ctrl_len);
> + of_property_read_u32(np, "pl022,wait-state",
> + &chip_info_dt.wait_state);
> + of_property_read_u32(np, "pl022,duplex",
> + &chip_info_dt.duplex);
> +
> + chip_info = &chip_info_dt;
> + } else {
> + chip_info = &pl022_default_chip_info;
> + /* spi_board_info.controller_data not is supplied */
> + dev_dbg(&spi->dev,
> + "using default controller_data settings\n");
> + }
> } else
> dev_dbg(&spi->dev,
> "using user supplied controller_data settings\n");
> @@ -1835,8 +1874,9 @@ static int pl022_setup(struct spi_device *spi)
> chip->xfer_type = chip_info->com_mode;
> if (!chip_info->cs_control) {
> chip->cs_control = null_cs_control;
> - dev_warn(&spi->dev,
> - "chip select function is NULL for this chip\n");
> + if (!gpio_is_valid(pl022->chipselect[spi->chip_select]))
> + dev_warn(&spi->dev,
> + "chip select function is NULL for this chip\n");
> } else
> chip->cs_control = chip_info->cs_control;
>
> @@ -1988,7 +2028,8 @@ pl022_probe(struct amba_device *adev, const struct amba_id *id)
> struct pl022_ssp_controller *platform_info = adev->dev.platform_data;
> struct spi_master *master;
> struct pl022 *pl022 = NULL; /*Data for this driver */
> - int status = 0;
> + struct device_node *np = adev->dev.of_node;
> + int status = 0, i, num_cs;
>
> dev_info(&adev->dev,
> "ARM PL022 driver, device ID: 0x%08x\n", adev->periphid);
> @@ -1998,8 +2039,14 @@ pl022_probe(struct amba_device *adev, const struct amba_id *id)
> goto err_no_pdata;
> }
>
> + num_cs = platform_info->num_chipselect;
> + if (IS_ENABLED(CONFIG_OF))
> + of_property_read_u32(np, "pl022,num-chipselects", &num_cs);
> +
> +
> /* Allocate master with space for data */
> - master = spi_alloc_master(dev, sizeof(struct pl022));
> + master = spi_alloc_master(dev,
> + sizeof(struct pl022) + sizeof(int) * num_cs);
> if (master == NULL) {
> dev_err(&adev->dev, "probe - cannot alloc SPI master\n");
> status = -ENOMEM;
> @@ -2017,13 +2064,41 @@ pl022_probe(struct amba_device *adev, const struct amba_id *id)
> * on this board
> */
> master->bus_num = platform_info->bus_id;
> - master->num_chipselect = platform_info->num_chipselect;
> + master->num_chipselect = num_cs;
> master->cleanup = pl022_cleanup;
> master->setup = pl022_setup;
> master->prepare_transfer_hardware = pl022_prepare_transfer_hardware;
> master->transfer_one_message = pl022_transfer_one_message;
> master->unprepare_transfer_hardware = pl022_unprepare_transfer_hardware;
> master->rt = platform_info->rt;
> + master->dev.of_node = dev->of_node;
> +
> + if (IS_ENABLED(CONFIG_OF)) {
> + for (i = 0; i < num_cs; i++) {
> + int cs_gpio = of_get_named_gpio(np, "cs-gpios", i);
> +
> + if (cs_gpio == -EPROBE_DEFER) {
> + status = -EPROBE_DEFER;
> + goto err_no_gpio;
> + }
> +
> + pl022->chipselect[i] = cs_gpio;
> +
> + if (gpio_is_valid(cs_gpio)) {
> + if (gpio_request(cs_gpio, "ssp-pl022"))
> + dev_err(&adev->dev,
> + "could not request %d gpio\n",
> + cs_gpio);
> + else if (gpio_direction_output(cs_gpio, 1))
> + dev_err(&adev->dev,
> + "could set gpio %d as output\n",
> + cs_gpio);
> + }
> + }
> + } else {
> + for (i = 0; i < num_cs; i++)
> + pl022->chipselect[i] = -EINVAL;
> + }
>
> /*
> * Supports mode 0-3, loopback, and active low CS. Transfers are
> @@ -2130,6 +2205,7 @@ pl022_probe(struct amba_device *adev, const struct amba_id *id)
> err_no_ioremap:
> amba_release_regions(adev);
> err_no_ioregion:
> + err_no_gpio:
> spi_master_put(master);
> err_no_master:
> err_no_pdata:
>
(Currently make sure to include Mark Brown (see To: line) on all SPI patches,
as he's collecting them.)
On Mon, Aug 20, 2012 at 1:39 PM, Alexandre Pereira da Silva
<[email protected]> wrote:
> Add the chipselect array and cur_cs properties to pl022 main structure
OK...
> diff --git a/Documentation/devicetree/bindings/spi/spi_pl022.txt b/Documentation/devicetree/bindings/spi/spi_pl022.txt
This looks fine to me.
> +#include <linux/gpio.h>
> +#include <linux/of_gpio.h>
Hm, it looks like two changes are embedded in this patch.
>
> /*
> * This macro is used to define some register default values.
> @@ -389,6 +391,8 @@ struct pl022 {
> char *dummypage;
> bool dma_running;
> #endif
> + int cur_cs;
> + int chipselect[0];
> };
You forgot to add kerneldoc for these two. Please add!
int chipselect[0] really? isn't int *chipselect what you really want
to store in there?
> + if (gpio_is_valid(pl022->cur_cs))
> + gpio_set_value(pl022->cur_cs, command);
> + else
> + pl022->cur_chip->cs_control(command);
> +}
So it seems like this should be two patches:
- One adding pl022->cur_cs and the ability for the driver to control
the chip select directly from msg->spi->chip_select
Make sure it is possible to populate pl022->chipselect also
from platform data since many people are using that
still.
- Another patch adding device tree and that stuff.
So please split it in two.
> - pl022->cur_chip->cs_control(SSP_CHIP_DESELECT);
> + pl022_cs_control(pl022, SSP_CHIP_DESELECT);
All these are OK and go in the first patch.
> + pl022->cur_cs = pl022->chipselect[msg->spi->chip_select];
Goes into the first patch...
> @@ -1761,12 +1772,14 @@ static const struct pl022_config_chip pl022_default_chip_info = {
> static int pl022_setup(struct spi_device *spi)
> {
> struct pl022_config_chip const *chip_info;
> + struct pl022_config_chip chip_info_dt;
Goes into second patch.
> struct chip_data *chip;
> struct ssp_clock_params clk_freq = { .cpsdvsr = 0, .scr = 0};
> int status = 0;
> struct pl022 *pl022 = spi_master_get_devdata(spi->master);
> unsigned int bits = spi->bits_per_word;
> u32 tmp;
> + struct device_node *np = spi->dev.of_node;
Does this compile if CONFIG_OF is not selected?
I have seen other drivers have #ifdef CONFIG_OF around these
things.
Make sure you test-compile without DT.
> @@ -1789,10 +1802,36 @@ static int pl022_setup(struct spi_device *spi)
> chip_info = spi->controller_data;
>
> if (chip_info == NULL) {
> - chip_info = &pl022_default_chip_info;
> - /* spi_board_info.controller_data not is supplied */
> - dev_dbg(&spi->dev,
> - "using default controller_data settings\n");
> + if (np) {
> + chip_info_dt = pl022_default_chip_info;
> +
> + of_property_read_u32(np, "pl022,hierarchy",
> + &chip_info_dt.hierarchy);
> + of_property_read_u32(np, "pl022,interface",
> + &chip_info_dt.iface);
> + chip_info_dt.slave_tx_disable =
> + of_property_read_bool(np,
> + "pl022,slave-tx-disable");
> + of_property_read_u32(np, "pl022,com-mode",
> + &chip_info_dt.com_mode);
> + of_property_read_u32(np, "pl022,rx-level-trig",
> + &chip_info_dt.rx_lev_trig);
> + of_property_read_u32(np, "pl022,tx-level-trig",
> + &chip_info_dt.tx_lev_trig);
> + of_property_read_u32(np, "pl022,ctrl-len",
> + &chip_info_dt.ctrl_len);
> + of_property_read_u32(np, "pl022,wait-state",
> + &chip_info_dt.wait_state);
> + of_property_read_u32(np, "pl022,duplex",
> + &chip_info_dt.duplex);
> +
> + chip_info = &chip_info_dt;
> + } else {
> + chip_info = &pl022_default_chip_info;
> + /* spi_board_info.controller_data not is supplied */
> + dev_dbg(&spi->dev,
> + "using default controller_data settings\n");
> + }
Goes into second patch.
> @@ -1835,8 +1874,9 @@ static int pl022_setup(struct spi_device *spi)
> chip->xfer_type = chip_info->com_mode;
> if (!chip_info->cs_control) {
> chip->cs_control = null_cs_control;
> - dev_warn(&spi->dev,
> - "chip select function is NULL for this chip\n");
> + if (!gpio_is_valid(pl022->chipselect[spi->chip_select]))
> + dev_warn(&spi->dev,
> + "chip select function is NULL for this chip\n");
> } else
> chip->cs_control = chip_info->cs_control;
Goes into first patch.
> @@ -1988,7 +2028,8 @@ pl022_probe(struct amba_device *adev, const struct amba_id *id)
> struct pl022_ssp_controller *platform_info = adev->dev.platform_data;
> struct spi_master *master;
> struct pl022 *pl022 = NULL; /*Data for this driver */
> - int status = 0;
> + struct device_node *np = adev->dev.of_node;
Does this compile without CONFIG_OF?
(Second patch)
> + int status = 0, i, num_cs;
>
> dev_info(&adev->dev,
> "ARM PL022 driver, device ID: 0x%08x\n", adev->periphid);
> @@ -1998,8 +2039,14 @@ pl022_probe(struct amba_device *adev, const struct amba_id *id)
> goto err_no_pdata;
> }
>
> + num_cs = platform_info->num_chipselect;
> + if (IS_ENABLED(CONFIG_OF))
> + of_property_read_u32(np, "pl022,num-chipselects", &num_cs);
> +
> +
Shouldn't it be the other way around: platform data overrides
DT data. Attempt DT and if platform_info->num_chipselect
!= 0 let it override.
(Second patch.)
> /* Allocate master with space for data */
> - master = spi_alloc_master(dev, sizeof(struct pl022));
> + master = spi_alloc_master(dev,
> + sizeof(struct pl022) + sizeof(int) * num_cs);
First patch.
> if (master == NULL) {
> dev_err(&adev->dev, "probe - cannot alloc SPI master\n");
> status = -ENOMEM;
> @@ -2017,13 +2064,41 @@ pl022_probe(struct amba_device *adev, const struct amba_id *id)
> * on this board
> */
> master->bus_num = platform_info->bus_id;
> - master->num_chipselect = platform_info->num_chipselect;
> + master->num_chipselect = num_cs;
OK first patch.
> master->cleanup = pl022_cleanup;
> master->setup = pl022_setup;
> master->prepare_transfer_hardware = pl022_prepare_transfer_hardware;
> master->transfer_one_message = pl022_transfer_one_message;
> master->unprepare_transfer_hardware = pl022_unprepare_transfer_hardware;
> master->rt = platform_info->rt;
> + master->dev.of_node = dev->of_node;
Does this compile without CONFIG_OF?
Second patch.
> + if (IS_ENABLED(CONFIG_OF)) {
> + for (i = 0; i < num_cs; i++) {
> + int cs_gpio = of_get_named_gpio(np, "cs-gpios", i);
> +
> + if (cs_gpio == -EPROBE_DEFER) {
> + status = -EPROBE_DEFER;
> + goto err_no_gpio;
> + }
> +
> + pl022->chipselect[i] = cs_gpio;
> +
> + if (gpio_is_valid(cs_gpio)) {
> + if (gpio_request(cs_gpio, "ssp-pl022"))
> + dev_err(&adev->dev,
> + "could not request %d gpio\n",
> + cs_gpio);
> + else if (gpio_direction_output(cs_gpio, 1))
> + dev_err(&adev->dev,
> + "could set gpio %d as output\n",
> + cs_gpio);
> + }
> + }
> + } else {
> + for (i = 0; i < num_cs; i++)
> + pl022->chipselect[i] = -EINVAL;
Why? Instead, add a int *chipselects; field to the struct pl022_ssp_controller
platform data in include/linux/amba/pl022.h and copy it from there if
num_chipselects in the same data != 0.
(First patch.)
Yours,
Linus Walleij
On Mon, Aug 20, 2012 at 4:22 PM, Rob Herring <[email protected]> wrote:
> On 08/20/2012 06:39 AM, Alexandre Pereira da Silva wrote:
>> +- pl022,hierarchy : master or slave interface
>
> Is attaching a master and using the pl022 as a slave really a supported
> use case?
No not currently. People doing this crazy stuff need to have
the kernel with the hard real-time patches and lightening response
first. But it's in the platform data because it's a feature supported by
the hardware.
> The DT spi bindings are really designed for a master node with
> N slave nodes. So there is more general question of how to describe a
> spi controller as a slave. It's not really one I care to answer as the
> Linux spi framework isn't designed to act as a slave.
Currently the code should hardwire this to master and not define
a binding for it I think.
>> +- pl022,slave-tx-disable : disconnect tx line in slave mode
Applies also to this, then.
>> +- pl022,com-mode : polling, interrupt or dma
>> +- pl022,rx-level-trig : Rx FIFO watermark level
>> +- pl022,tx-level-trig : Tx FIFO watermark level
>> +- pl022,ctrl-len : Microwire interface: Control length
>> +- pl022,wait-state : Microwire interface: Wait state
>> +- pl022,duplex : Microwire interface: Full/Half duplex
>
> Most of these properties aren't used anywhere in the kernel other than
> u300 and I'm not sure what to purpose of dummy_chip_info is.
It is used for loopback-testing of the PL022. They're probably
not necessary there either.
> Perhaps
> Linus has some input? I think either they can be decided by the spi
> controller (com-mode, fifo watermark) or should be standard properties
> (microwire settings). I would argue they should be removed if the spi
> framework doesn't have support in a standard way.
Uncertain about this, others would need to comment.
At some point there has been a chip needing these to be set
to some magic values.
Yours,
Linus Walleij
On 08/20/2012 04:22 PM, Rob Herring wrote:
>> .../devicetree/bindings/spi/spi_pl022.txt | 15 +++
>> drivers/spi/spi-pl022.c | 114 ++++++++++++++++----
>> 2 files changed, 110 insertions(+), 19 deletions(-)
>>
>> diff --git a/Documentation/devicetree/bindings/spi/spi_pl022.txt b/Documentation/devicetree/bindings/spi/spi_pl022.txt
>> index 306ec3f..b089ec7 100644
>> --- a/Documentation/devicetree/bindings/spi/spi_pl022.txt
>> +++ b/Documentation/devicetree/bindings/spi/spi_pl022.txt
>> @@ -6,7 +6,22 @@ Required properties:
>> - interrupts : Should contain SPI controller interrupt
>>
>> Optional properties:
>> +- pl022,num-chipselects : total number of chipselects
>
> We have this for other spi controllers too. Define a generic property.
Currently, we have:
num-cs
ti,spi-num-cs
fsl,spi-num-chipselects
fsl,espi-num-chipselects
(pl022,num-chipselects)
Would "num-cs" be the right one to use?
Thanks,
Roland
On 08/20/2012 10:33 AM, Roland Stigge wrote:
> On 08/20/2012 04:22 PM, Rob Herring wrote:
>>> .../devicetree/bindings/spi/spi_pl022.txt | 15 +++
>>> drivers/spi/spi-pl022.c | 114 ++++++++++++++++----
>>> 2 files changed, 110 insertions(+), 19 deletions(-)
>>>
>>> diff --git a/Documentation/devicetree/bindings/spi/spi_pl022.txt b/Documentation/devicetree/bindings/spi/spi_pl022.txt
>>> index 306ec3f..b089ec7 100644
>>> --- a/Documentation/devicetree/bindings/spi/spi_pl022.txt
>>> +++ b/Documentation/devicetree/bindings/spi/spi_pl022.txt
>>> @@ -6,7 +6,22 @@ Required properties:
>>> - interrupts : Should contain SPI controller interrupt
>>>
>>> Optional properties:
>>> +- pl022,num-chipselects : total number of chipselects
>>
>> We have this for other spi controllers too. Define a generic property.
>
> Currently, we have:
>
> num-cs
> ti,spi-num-cs
> fsl,spi-num-chipselects
> fsl,espi-num-chipselects
> (pl022,num-chipselects)
>
> Would "num-cs" be the right one to use?
Well, it is either that or invent something new, so I think num-cs is fine.
Rob