Commit f34f3716 authored by Gupta Pekon's avatar Gupta Pekon Committed by Tony Lindgren
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ARM: OMAP2+: gpmc: get number of useable GPMC chip-selects via DT 



This patch enables usage of DT property 'gpmc,num-cs' as already documented in
Documentation/devicetree/bindings/bus/ti-gpmc.txt

Though GPMC hardware supports upto 8 chip-selects, but all chip-selects may
not be available for use because:
- chip-select pin may not be bonded out at SoC device boundary.
- chip-select pin-mux may conflict with other pins usage.
- board level constrains.

gpmc,num-cs allows user to configure maximum number of GPMC chip-selects
available for use on any given platform. This ensures:
- GPMC child nodes having chip-selects within allowed range are only probed.
- And un-used GPMC chip-selects remain blocked.(may be for security reasons).

Signed-off-by: default avatarGupta, Pekon <pekon@ti.com>
Signed-off-by: default avatarTony Lindgren <tony@atomide.com>
parent f40739fa

arch/arm/mach-omap2/gpmc.c

+29 −9
Original line number Diff line number Diff line
@@ -155,6 +155,7 @@ static struct resource gpmc_cs_mem[GPMC_CS_NUM]; 
static DEFINE_SPINLOCK(gpmc_mem_lock);

/* Define chip-selects as reserved by default until probe completes */

static unsigned int gpmc_cs_map = ((1 << GPMC_CS_NUM) - 1);

static unsigned int gpmc_cs_num = GPMC_CS_NUM;

static unsigned int gpmc_nr_waitpins;

static struct device *gpmc_dev;

static int gpmc_irq;
@@ -521,8 +522,10 @@ static int gpmc_cs_remap(int cs, u32 base) 
	int ret;

	u32 old_base, size;



	if (cs > GPMC_CS_NUM)

	if (cs > gpmc_cs_num) {

		pr_err("%s: requested chip-select is disabled\n", __func__);

		return -ENODEV;

	}

	gpmc_cs_get_memconf(cs, &old_base, &size);

	if (base == old_base)

		return 0;
@@ -545,9 +548,10 @@ int gpmc_cs_request(int cs, unsigned long size, unsigned long *base) 
	struct resource *res = &gpmc_cs_mem[cs];

	int r = -1;



	if (cs > GPMC_CS_NUM)

	if (cs > gpmc_cs_num) {

		pr_err("%s: requested chip-select is disabled\n", __func__);

		return -ENODEV;



	}

	size = gpmc_mem_align(size);

	if (size > (1 << GPMC_SECTION_SHIFT))

		return -ENOMEM;
@@ -582,7 +586,7 @@ EXPORT_SYMBOL(gpmc_cs_request); 
void gpmc_cs_free(int cs)

{

	spin_lock(&gpmc_mem_lock);

	if (cs >= GPMC_CS_NUM || cs < 0 || !gpmc_cs_reserved(cs)) {

	if (cs >= gpmc_cs_num || cs < 0 || !gpmc_cs_reserved(cs)) {

		printk(KERN_ERR "Trying to free non-reserved GPMC CS%d\n", cs);

		BUG();

		spin_unlock(&gpmc_mem_lock);
@@ -777,7 +781,7 @@ static void gpmc_mem_exit(void) 
{

	int cs;



	for (cs = 0; cs < GPMC_CS_NUM; cs++) {

	for (cs = 0; cs < gpmc_cs_num; cs++) {

		if (!gpmc_cs_mem_enabled(cs))

			continue;

		gpmc_cs_delete_mem(cs);
@@ -798,7 +802,7 @@ static void gpmc_mem_init(void) 
	gpmc_mem_root.end = GPMC_MEM_END;



	/* Reserve all regions that has been set up by bootloader */

	for (cs = 0; cs < GPMC_CS_NUM; cs++) {

	for (cs = 0; cs < gpmc_cs_num; cs++) {

		u32 base, size;



		if (!gpmc_cs_mem_enabled(cs))
@@ -1526,6 +1530,20 @@ static int gpmc_probe_dt(struct platform_device *pdev) 
	if (!of_id)

		return 0;



	ret = of_property_read_u32(pdev->dev.of_node, "gpmc,num-cs",

				   &gpmc_cs_num);

	if (ret < 0) {

		pr_err("%s: number of chip-selects not defined\n", __func__);

		return ret;

	} else if (gpmc_cs_num < 1) {

		pr_err("%s: all chip-selects are disabled\n", __func__);

		return -EINVAL;

	} else if (gpmc_cs_num > GPMC_CS_NUM) {

		pr_err("%s: number of supported chip-selects cannot be > %d\n",

					 __func__, GPMC_CS_NUM);

		return -EINVAL;

	}



	ret = of_property_read_u32(pdev->dev.of_node, "gpmc,num-waitpins",

				   &gpmc_nr_waitpins);

	if (ret < 0) {
@@ -1623,8 +1641,10 @@ static int gpmc_probe(struct platform_device *pdev) 
	/* Now the GPMC is initialised, unreserve the chip-selects */

	gpmc_cs_map = 0;



	if (!pdev->dev.of_node)

	if (!pdev->dev.of_node) {

		gpmc_cs_num	 = GPMC_CS_NUM;

		gpmc_nr_waitpins = GPMC_NR_WAITPINS;

	}



	rc = gpmc_probe_dt(pdev);

	if (rc < 0) {
@@ -1728,7 +1748,7 @@ void omap3_gpmc_save_context(void) 
	gpmc_context.prefetch_config1 = gpmc_read_reg(GPMC_PREFETCH_CONFIG1);

	gpmc_context.prefetch_config2 = gpmc_read_reg(GPMC_PREFETCH_CONFIG2);

	gpmc_context.prefetch_control = gpmc_read_reg(GPMC_PREFETCH_CONTROL);

	for (i = 0; i < GPMC_CS_NUM; i++) {

	for (i = 0; i < gpmc_cs_num; i++) {

		gpmc_context.cs_context[i].is_valid = gpmc_cs_mem_enabled(i);

		if (gpmc_context.cs_context[i].is_valid) {

			gpmc_context.cs_context[i].config1 =
@@ -1760,7 +1780,7 @@ void omap3_gpmc_restore_context(void) 
	gpmc_write_reg(GPMC_PREFETCH_CONFIG1, gpmc_context.prefetch_config1);

	gpmc_write_reg(GPMC_PREFETCH_CONFIG2, gpmc_context.prefetch_config2);

	gpmc_write_reg(GPMC_PREFETCH_CONTROL, gpmc_context.prefetch_control);

	for (i = 0; i < GPMC_CS_NUM; i++) {

	for (i = 0; i < gpmc_cs_num; i++) {

		if (gpmc_context.cs_context[i].is_valid) {

			gpmc_cs_write_reg(i, GPMC_CS_CONFIG1,

				gpmc_context.cs_context[i].config1);

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