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* [PATCH 0/6] Misc driver fixes for 2.6.32
@ 2009-11-05 15:25 Ralf Baechle
  2009-11-05 15:26 ` [PATCH 4/6] SPI: spi_txx9: Fix bit rate calculation Ralf Baechle
  0 siblings, 1 reply; 2+ messages in thread
From: Ralf Baechle @ 2009-11-05 15:25 UTC (permalink / raw)
  To: Linus Torvalds
  Cc: David Daney, Atsushi Nemoto, Julia Lawall, Greg Kroah-Hartman,
	devel, David Brownell, spi-devel-general, linux-kernel,
	linux-mips, netdev

This is a series of patches which 

  o 1/6, 2/6, 3/6: Fixes for the Octeon ethernet driver in drivers/staging.
    The Octeon is a MIPS-based SOC so with permisson from Greg I'm merging
    these via the MIPS tree.
  o 4/6: A fix to a MIPS-specific SPI driver.  Posted before, no comments
    were received.
  o 5/6: A fix to the resource allocation to the framebuffer of the MIPS-
    based SGI O2 and i686-based Visual Workstation.  Also posted before, no
    comments were received.
  o 6/6: A fix to the serial driver for the BCM63xx which is a MIPS-based
    SOC.

  Ralf


^ permalink raw reply	[flat|nested] 2+ messages in thread

* [PATCH 4/6] SPI: spi_txx9: Fix bit rate calculation
  2009-11-05 15:25 [PATCH 0/6] Misc driver fixes for 2.6.32 Ralf Baechle
@ 2009-11-05 15:26 ` Ralf Baechle
  0 siblings, 0 replies; 2+ messages in thread
From: Ralf Baechle @ 2009-11-05 15:26 UTC (permalink / raw)
  To: Linus Torvalds
  Cc: spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f,
	Atsushi Nemoto, David Brownell,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA

[-- Attachment #1: 0005.patch --]
[-- Type: text/plain, Size: 2302 bytes --]

From: Atsushi Nemoto <anemo-7JcRY8pycbNHfZP73Gtkiw@public.gmane.org>

TXx9 SPI bit rate is calculated by:
        fBR = (spi-baseclk) / (n + 1)
Fix calculation of min_speed_hz, max_speed_hz and n.

Signed-off-by: Atsushi Nemoto <anemo-7JcRY8pycbNHfZP73Gtkiw@public.gmane.org>
Cc: David Brownell <dbrownell-Rn4VEauK+AKRv+LV9MX5uipxlwaOVQ5f@public.gmane.org>
Cc: spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org
Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Signed-off-by: Ralf Baechle <ralf-6z/3iImG2C8G8FEW9MqTrA@public.gmane.org>

 drivers/spi/spi_txx9.c |   13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

Index: upstream-linus/drivers/spi/spi_txx9.c
===================================================================
--- upstream-linus.orig/drivers/spi/spi_txx9.c
+++ upstream-linus/drivers/spi/spi_txx9.c
@@ -29,6 +29,8 @@
 
 
 #define SPI_FIFO_SIZE 4
+#define SPI_MAX_DIVIDER 0xff	/* Max. value for SPCR1.SER */
+#define SPI_MIN_DIVIDER 1	/* Min. value for SPCR1.SER */
 
 #define TXx9_SPMCR		0x00
 #define TXx9_SPCR0		0x04
@@ -193,11 +195,8 @@ static void txx9spi_work_one(struct txx9
 
 		if (prev_speed_hz != speed_hz
 				|| prev_bits_per_word != bits_per_word) {
-			u32 n = (c->baseclk + speed_hz - 1) / speed_hz;
-			if (n < 1)
-				n = 1;
-			else if (n > 0xff)
-				n = 0xff;
+			int n = DIV_ROUND_UP(c->baseclk, speed_hz) - 1;
+			n = clamp(n, SPI_MIN_DIVIDER, SPI_MAX_DIVIDER);
 			/* enter config mode */
 			txx9spi_wr(c, mcr | TXx9_SPMCR_CONFIG | TXx9_SPMCR_BCLR,
 					TXx9_SPMCR);
@@ -370,8 +369,8 @@ static int __init txx9spi_probe(struct p
 		goto exit;
 	}
 	c->baseclk = clk_get_rate(c->clk);
-	c->min_speed_hz = (c->baseclk + 0xff - 1) / 0xff;
-	c->max_speed_hz = c->baseclk;
+	c->min_speed_hz = DIV_ROUND_UP(c->baseclk, SPI_MAX_DIVIDER + 1);
+	c->max_speed_hz = c->baseclk / (SPI_MIN_DIVIDER + 1);
 
 	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
 	if (!res)



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