Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 2e676901 authored by Robert ABEL's avatar Robert ABEL Committed by Roger Quadros
Browse files

ARM OMAP2+ GPMC: calculate GPMCFCLKDIVIDER based on WAITMONITORINGTIME 



The WAITMONITORINGTIME is expressed as a number of GPMC_CLK clock cycles,
even though the access is defined as asynchronous, and no GPMC_CLK clock
is provided to the external device. Still, GPMCFCLKDIVIDER is used as a divider
for the GPMC clock, so it must be programmed to define the
correct WAITMONITORINGTIME delay.

Calculate GPMCFCLKDIVIDER independent of gpmc,sync-clk-ps in DT for
pure asynchronous accesses, i.e. both read and write asynchronous.

Signed-off-by: default avatarRobert ABEL <rabel@cit-ec.uni-bielefeld.de>
Acked-by: default avatarTony Lindgren <tony@atomide.com>
Signed-off-by: default avatarRoger Quadros <rogerq@ti.com>
parent f585070b

arch/arm/mach-omap2/gpmc-nand.c

+10 −8
Original line number Diff line number Diff line
@@ -96,14 +96,6 @@ int gpmc_nand_init(struct omap_nand_platform_data *gpmc_nand_data, 
	gpmc_nand_res[1].start = gpmc_get_client_irq(GPMC_IRQ_FIFOEVENTENABLE);

	gpmc_nand_res[2].start = gpmc_get_client_irq(GPMC_IRQ_COUNT_EVENT);



	if (gpmc_t) {

		err = gpmc_cs_set_timings(gpmc_nand_data->cs, gpmc_t);

		if (err < 0) {

			pr_err("omap2-gpmc: Unable to set gpmc timings: %d\n", err);

			return err;

		}

	}



	memset(&s, 0, sizeof(struct gpmc_settings));

	if (gpmc_nand_data->of_node)

		gpmc_read_settings_dt(gpmc_nand_data->of_node, &s);
@@ -111,6 +103,16 @@ int gpmc_nand_init(struct omap_nand_platform_data *gpmc_nand_data, 
		gpmc_set_legacy(gpmc_nand_data, &s);



	s.device_nand = true;



	if (gpmc_t) {

		err = gpmc_cs_set_timings(gpmc_nand_data->cs, gpmc_t, &s);

		if (err < 0) {

			pr_err("omap2-gpmc: Unable to set gpmc timings: %d\n",

			       err);

			return err;

		}

	}



	err = gpmc_cs_program_settings(gpmc_nand_data->cs, &s);

	if (err < 0)

		goto out_free_cs;

arch/arm/mach-omap2/gpmc-onenand.c

+2 −2
Original line number Diff line number Diff line
@@ -293,7 +293,7 @@ static int omap2_onenand_setup_async(void __iomem *onenand_base) 
	if (ret < 0)

		return ret;



	ret = gpmc_cs_set_timings(gpmc_onenand_data->cs, &t);

	ret = gpmc_cs_set_timings(gpmc_onenand_data->cs, &t, &onenand_async);

	if (ret < 0)

		return ret;
@@ -331,7 +331,7 @@ static int omap2_onenand_setup_sync(void __iomem *onenand_base, int *freq_ptr) 
	if (ret < 0)

		return ret;



	ret = gpmc_cs_set_timings(gpmc_onenand_data->cs, &t);

	ret = gpmc_cs_set_timings(gpmc_onenand_data->cs, &t, &onenand_sync);

	if (ret < 0)

		return ret;

arch/arm/mach-omap2/usb-tusb6010.c

+2 −2
Original line number Diff line number Diff line
@@ -71,7 +71,7 @@ static int tusb_set_async_mode(unsigned sysclk_ps) 


	gpmc_calc_timings(&t, &tusb_async, &dev_t);



	return gpmc_cs_set_timings(async_cs, &t);

	return gpmc_cs_set_timings(async_cs, &t, &tusb_async);

}



static int tusb_set_sync_mode(unsigned sysclk_ps)
@@ -98,7 +98,7 @@ static int tusb_set_sync_mode(unsigned sysclk_ps) 


	gpmc_calc_timings(&t, &tusb_sync, &dev_t);



	return gpmc_cs_set_timings(sync_cs, &t);

	return gpmc_cs_set_timings(sync_cs, &t, &tusb_sync);

}



/* tusb driver calls this when it changes the chip's clocking */

drivers/memory/omap-gpmc.c

+79 −7
Original line number Diff line number Diff line
@@ -138,7 +138,9 @@ 
#define GPMC_CONFIG1_PAGE_LEN(val)      ((val & 3) << 23)

#define GPMC_CONFIG1_WAIT_READ_MON      (1 << 22)

#define GPMC_CONFIG1_WAIT_WRITE_MON     (1 << 21)

#define GPMC_CONFIG1_WAIT_MON_IIME(val) ((val & 3) << 18)

#define GPMC_CONFIG1_WAIT_MON_TIME(val) ((val & 3) << 18)

/** WAITMONITORINGTIME Max Ticks */

#define GPMC_CONFIG1_WAITMONITORINGTIME_MAX  2

#define GPMC_CONFIG1_WAIT_PIN_SEL(val)  ((val & 3) << 16)

#define GPMC_CONFIG1_DEVICESIZE(val)    ((val & 3) << 12)

#define GPMC_CONFIG1_DEVICESIZE_16      GPMC_CONFIG1_DEVICESIZE(1)
@@ -525,13 +527,48 @@ static int set_gpmc_timing_reg(int cs, int reg, int st_bit, int end_bit, 
			t->field, #field) < 0)			\

		return -1



/**

 * gpmc_calc_waitmonitoring_divider - calculate proper GPMCFCLKDIVIDER based on WAITMONITORINGTIME

 * WAITMONITORINGTIME will be _at least_ as long as desired, i.e.

 * read  --> don't sample bus too early

 * write --> data is longer on bus

 *

 * Formula:

 * gpmc_clk_div + 1 = ceil(ceil(waitmonitoringtime_ns / gpmc_fclk_ns)

 *                    / waitmonitoring_ticks)

 * WAITMONITORINGTIME resulting in 0 or 1 tick with div = 1 are caught by

 * div <= 0 check.

 *

 * @wait_monitoring: WAITMONITORINGTIME in ns.

 * @return:          -1 on failure to scale, else proper divider > 0.

 */

static int gpmc_calc_waitmonitoring_divider(unsigned int wait_monitoring)

{



	int div = gpmc_ns_to_ticks(wait_monitoring);



	div += GPMC_CONFIG1_WAITMONITORINGTIME_MAX - 1;

	div /= GPMC_CONFIG1_WAITMONITORINGTIME_MAX;



	if (div > 4)

		return -1;

	if (div <= 0)

		div = 1;



	return div;



}



/**

 * gpmc_calc_divider - calculate GPMC_FCLK divider for sync_clk GPMC_CLK period.

 * @sync_clk: GPMC_CLK period in ps.

 * @return:   Returns at least 1 if GPMC_FCLK can be divided to GPMC_CLK.

 *            Else, returns -1.

 */

int gpmc_calc_divider(unsigned int sync_clk)

{

	int div;

	u32 l;

	int div = gpmc_ps_to_ticks(sync_clk);



	l = sync_clk + (gpmc_get_fclk_period() - 1);

	div = l / gpmc_get_fclk_period();

	if (div > 4)

		return -1;

	if (div <= 0)
@@ -540,7 +577,15 @@ int gpmc_calc_divider(unsigned int sync_clk) 
	return div;

}



int gpmc_cs_set_timings(int cs, const struct gpmc_timings *t)

/**

 * gpmc_cs_set_timings - program timing parameters for Chip Select Region.

 * @cs:     Chip Select Region.

 * @t:      GPMC timing parameters.

 * @s:      GPMC timing settings.

 * @return: 0 on success, -1 on error.

 */

int gpmc_cs_set_timings(int cs, const struct gpmc_timings *t,

			const struct gpmc_settings *s)

{

	int div;

	u32 l;
@@ -550,6 +595,33 @@ int gpmc_cs_set_timings(int cs, const struct gpmc_timings *t) 
	if (div < 0)

		return div;



	/*

	 * See if we need to change the divider for waitmonitoringtime.

	 *

	 * Calculate GPMCFCLKDIVIDER independent of gpmc,sync-clk-ps in DT for

	 * pure asynchronous accesses, i.e. both read and write asynchronous.

	 * However, only do so if WAITMONITORINGTIME is actually used, i.e.

	 * either WAITREADMONITORING or WAITWRITEMONITORING is set.

	 *

	 * This statement must not change div to scale async WAITMONITORINGTIME

	 * to protect mixed synchronous and asynchronous accesses.

	 *

	 * We raise an error later if WAITMONITORINGTIME does not fit.

	 */

	if (!s->sync_read && !s->sync_write &&

	    (s->wait_on_read || s->wait_on_write)

	   ) {



		div = gpmc_calc_waitmonitoring_divider(t->wait_monitoring);

		if (div < 0) {

			pr_err("%s: waitmonitoringtime %3d ns too large for greatest gpmcfclkdivider.\n",

			       __func__,

			       t->wait_monitoring

			       );

			return -1;

		}

	}



	GPMC_SET_ONE(GPMC_CS_CONFIG2,  0,  3, cs_on);

	GPMC_SET_ONE(GPMC_CS_CONFIG2,  8, 12, cs_rd_off);

	GPMC_SET_ONE(GPMC_CS_CONFIG2, 16, 20, cs_wr_off);
@@ -1810,7 +1882,7 @@ static int gpmc_probe_generic_child(struct platform_device *pdev, 
	if (ret < 0)

		goto err;



	ret = gpmc_cs_set_timings(cs, &gpmc_t);

	ret = gpmc_cs_set_timings(cs, &gpmc_t, &gpmc_s);

	if (ret) {

		dev_err(&pdev->dev, "failed to set gpmc timings for: %s\n",

			child->name);

include/linux/omap-gpmc.h

+2 −1
Original line number Diff line number Diff line
@@ -163,7 +163,8 @@ extern unsigned int gpmc_ticks_to_ns(unsigned int ticks); 


extern void gpmc_cs_write_reg(int cs, int idx, u32 val);

extern int gpmc_calc_divider(unsigned int sync_clk);

extern int gpmc_cs_set_timings(int cs, const struct gpmc_timings *t);

extern int gpmc_cs_set_timings(int cs, const struct gpmc_timings *t,

			       const struct gpmc_settings *s);

extern int gpmc_cs_program_settings(int cs, struct gpmc_settings *p);

extern int gpmc_cs_request(int cs, unsigned long size, unsigned long *base);

extern void gpmc_cs_free(int cs);