[PATCH 4.0 41/58] spi: orion: Fix maximum baud rates for Armada 370/XP

From	Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Newsgroups	linux.kernel
Subject	[PATCH 4.0 41/58] spi: orion: Fix maximum baud rates for Armada 370/XP
Date	2015-07-19 21:30 +0200
Message-ID	<pO2rE-3BN-17@gated-at.bofh.it> (permalink)
References	<pO2hX-3q1-3@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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4.0-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Gregory CLEMENT <gregory.clement@free-electrons.com>

commit ce2f6ea1cbd41d78224f703af980a6ceeb0eb56a upstream.

The commit df59fa7f4bca "spi: orion: support armada extended baud
rates" was too optimistic for the maximum baud rate that the Armada
SoCs can support. According to the hardware datasheet the maximum
frequency supported by the Armada 370 SoC is tclk/4. But for the
Armada XP, Armada 38x and Armada 39x SoCs the limitation is 50MHz and
for the Armada 375 it is tclk/15.

Currently the armada-370-spi compatible is only used by the Armada 370
and the Armada XP device tree. On Armada 370, tclk cannot be higher
than 200MHz. In order to be able to handle both SoCs, we can take the
minimum of 50MHz and tclk/4.

A proper solution is adding a compatible string for each SoC, but it
can't be done as a fix for compatibility reason (we can't modify
device tree that have been already released) and it will be part of a
separate patch.

Fixes: df59fa7f4bca (spi: orion: support armada extended baud rates)
Reported-by: Kostya Porotchkin <kostap@marvell.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/spi/spi-orion.c |   25 +++++++++++++++++++++++--
 1 file changed, 23 insertions(+), 2 deletions(-)

--- a/drivers/spi/spi-orion.c
+++ b/drivers/spi/spi-orion.c
@@ -61,6 +61,12 @@ enum orion_spi_type {
 
 struct orion_spi_dev {
 	enum orion_spi_type	typ;
+	/*
+	 * min_divisor and max_hz should be exclusive, the only we can
+	 * have both is for managing the armada-370-spi case with old
+	 * device tree
+	 */
+	unsigned long		max_hz;
 	unsigned int		min_divisor;
 	unsigned int		max_divisor;
 	u32			prescale_mask;
@@ -387,8 +393,9 @@ static const struct orion_spi_dev orion_
 
 static const struct orion_spi_dev armada_spi_dev_data = {
 	.typ = ARMADA_SPI,
-	.min_divisor = 1,
+	.min_divisor = 4,
 	.max_divisor = 1920,
+	.max_hz = 50000000,
 	.prescale_mask = ARMADA_SPI_CLK_PRESCALE_MASK,
 };
 
@@ -454,7 +461,21 @@ static int orion_spi_probe(struct platfo
 		goto out;
 
 	tclk_hz = clk_get_rate(spi->clk);
-	master->max_speed_hz = DIV_ROUND_UP(tclk_hz, devdata->min_divisor);
+
+	/*
+	 * With old device tree, armada-370-spi could be used with
+	 * Armada XP, however for this SoC the maximum frequency is
+	 * 50MHz instead of tclk/4. On Armada 370, tclk cannot be
+	 * higher than 200MHz. So, in order to be able to handle both
+	 * SoCs, we can take the minimum of 50MHz and tclk/4.
+	 */
+	if (of_device_is_compatible(pdev->dev.of_node,
+					"marvell,armada-370-spi"))
+		master->max_speed_hz = min(devdata->max_hz,
+				DIV_ROUND_UP(tclk_hz, devdata->min_divisor));
+	else
+		master->max_speed_hz =
+			DIV_ROUND_UP(tclk_hz, devdata->min_divisor);
 	master->min_speed_hz = DIV_ROUND_UP(tclk_hz, devdata->max_divisor);
 
 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);


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Thread

[PATCH 4.0 00/58] 4.0.9-stable review Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-07-19 21:20 +0200
  [PATCH 4.0 36/58] regmap: Fix possible shift overflow in regmap_field_init() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-07-19 21:20 +0200
  [PATCH 4.0 57/58] of/pci: Fix pci_address_to_pio() conversion of CPU address to I/O port Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-07-19 21:20 +0200
  [PATCH 4.0 35/58] regmap: Fix regmap_bulk_read in BE mode Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-07-19 21:20 +0200
  [PATCH 4.0 22/58] tools selftests: Fix clean target with make 3.81 Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-07-19 21:20 +0200
  [PATCH 4.0 09/58] sysfs: Create mountpoints with sysfs_create_mount_point Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-07-19 21:20 +0200
  [PATCH 4.0 20/58] ACPI / PM: Add missing pm_generic_complete() invocation Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-07-19 21:20 +0200
  [PATCH 4.0 33/58] mm, thp: respect MPOL_PREFERRED policy with non-local node Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-07-19 21:20 +0200
  [PATCH 4.0 24/58] ARC: add compiler barrier to LLSC based cmpxchg Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-07-19 21:20 +0200
  [PATCH 4.0 44/58] scsi_transport_srp: Fix a race condition Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-07-19 21:20 +0200
  [PATCH 4.0 19/58] ACPI / init: Switch over platform to the ACPI mode later Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-07-19 21:20 +0200
  [PATCH 4.0 32/58] mm: kmemleak_alloc_percpu() should follow the gfp from per_alloc() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-07-19 21:20 +0200
  [PATCH 4.0 31/58] mm: kmemleak: allow safe memory scanning during kmemleak disabling Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-07-19 21:20 +0200
  [PATCH 4.0 18/58] ALSA: hda - Fix the dock headphone output on Fujitsu Lifebook E780 Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-07-19 21:20 +0200
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  [PATCH 4.0 07/58] mnt: Refactor the logic for mounting sysfs and proc in a user namespace Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-07-19 21:20 +0200
  [PATCH 4.0 26/58] mei: txe: reduce suspend/resume time Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-07-19 21:20 +0200
  [PATCH 4.0 15/58] ALSA: hda - Fix Dock Headphone on Thinkpad X250 seen as a Line Out Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-07-19 21:20 +0200
  [PATCH 4.0 29/58] arm64: mm: Fix freeing of the wrong memmap entries with !SPARSEMEM_VMEMMAP Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-07-19 21:20 +0200
  [PATCH 4.0 30/58] arm64: vdso: work-around broken ELF toolchains in Makefile Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-07-19 21:20 +0200
  [PATCH 4.0 25/58] mei: me: wait for power gating exit confirmation Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-07-19 21:20 +0200
  [PATCH 4.0 27/58] arm64: Do not attempt to use init_mm in reset_context() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-07-19 21:20 +0200
  [PATCH 4.0 28/58] arm64: entry: fix context tracking for el0_sp_pc Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-07-19 21:20 +0200
  [PATCH 4.0 21/58] iio: accel: kxcjk-1013: add the "KXCJ9000" ACPI id Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-07-19 21:20 +0200
  [PATCH 4.0 17/58] ALSA: hda - Add headset support to Acer Aspire V5 Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-07-19 21:20 +0200
  [PATCH 4.0 08/58] mnt: Modify fs_fully_visible to deal with locked ro nodev and atime Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-07-19 21:20 +0200
  [PATCH 4.0 16/58] ALSA: hda - set proper caps for newer AMD hda audio in KB/KV Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-07-19 21:20 +0200
  [PATCH 4.0 58/58] Input: pixcir_i2c_ts - fix receive error Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-07-19 21:20 +0200
  [PATCH 4.0 02/58] sysctl: Allow creating permanently empty directories that serve as mountpoints. Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-07-19 21:30 +0200
  [PATCH 4.0 39/58] livepatch: add module locking around kallsyms calls Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-07-19 21:30 +0200
  [PATCH 4.0 55/58] PCI: Add pci_bus_addr_t Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-07-19 21:30 +0200
  [PATCH 4.0 41/58] spi: orion: Fix maximum baud rates for Armada 370/XP Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-07-19 21:30 +0200
  [PATCH 4.0 52/58] mtd: fix: avoid race condition when accessing mtd->usecount Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-07-19 21:30 +0200
  [PATCH 4.0 14/58] ALSA: pcm: Fix pcm_class sysfs output Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-07-19 21:30 +0200
  [PATCH 4.0 38/58] regulator: core: fix constraints output buffer Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-07-19 21:30 +0200
  [PATCH 4.0 05/58] sysfs: Add support for permanently empty directories to serve as mount points. Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-07-19 21:30 +0200
  [PATCH 4.0 12/58] ipr: Increase default adapter init stage change timeout Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-07-19 21:30 +0200
  [PATCH 4.0 37/58] regulator: max77686: fix gpio_enabled shift wrapping bug Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-07-19 21:30 +0200
  [PATCH 4.0 47/58] IB/srp: Fix connection state tracking Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-07-19 21:30 +0200
  [PATCH 4.0 56/58] PCI: pciehp: Wait for hotplug command completion where necessary Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-07-19 21:30 +0200
  [PATCH 4.0 42/58] spi: pl022: Specify num-cs property as required in devicetree binding Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-07-19 21:30 +0200
  [PATCH 4.0 43/58] scsi_transport_srp: Introduce srp_wait_for_queuecommand() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-07-19 21:30 +0200
  [PATCH 4.0 48/58] IB/srp: Fix reconnection failure handling Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-07-19 21:30 +0200
  [PATCH 4.0 45/58] IB/srp: Remove an extraneous scsi_host_put() from an error path Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-07-19 21:30 +0200
  [PATCH 4.0 03/58] proc: Allow creating permanently empty directories that serve as mount points Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-07-19 21:30 +0200
  [PATCH 4.0 13/58] Disable write buffering on Toshiba ToPIC95 Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-07-19 21:30 +0200
  [PATCH 4.0 46/58] IB/srp: Fix a connection setup race Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-07-19 21:30 +0200
  [PATCH 4.0 54/58] PCI: Propagate the "ignore hotplug" setting to parent Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-07-19 21:30 +0200
  [PATCH 4.0 04/58] kernfs: Add support for always empty directories. Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-07-19 21:30 +0200
  [PATCH 4.0 50/58] video: mxsfb: Make sure axi clock is enabled when accessing registers Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-07-19 21:30 +0200
  [PATCH 4.0 06/58] mnt: Update fs_fully_visible to test for permanently empty directories Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-07-19 21:30 +0200
  [PATCH 4.0 01/58] fs: Add helper functions for permanently empty directories. Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-07-19 21:30 +0200
  [PATCH 4.0 49/58] genirq: devres: Fix testing return value of request_any_context_irq() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-07-19 21:30 +0200
  [PATCH 4.0 10/58] gpio: crystalcove: set IRQCHIP_SKIP_SET_WAKE for the irqchip Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-07-19 21:30 +0200
  [PATCH 4.0 51/58] leds / PM: fix hibernation on arm when gpio-led used with CPU led trigger Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-07-19 21:30 +0200
  Re: [PATCH 4.0 00/58] 4.0.9-stable review Shuah Khan <shuahkh@osg.samsung.com> - 2015-07-20 19:20 +0200

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