LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Sven Peter <sven@svenpeter.dev>
To: Michael Ellerman <mpe@ellerman.id.au>,
	Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	Paul Mackerras <paulus@samba.org>,
	Olof Johansson <olof@lixom.net>
Cc: Sven Peter <sven@svenpeter.dev>, Arnd Bergmann <arnd@arndb.de>,
	Hector Martin <marcan@marcan.st>,
	Mohamed Mediouni <mohamed.mediouni@caramail.com>,
	Stan Skowronek <stan@corellium.com>,
	Mark Kettenis <mark.kettenis@xs4all.nl>,
	Alyssa Rosenzweig <alyssa@rosenzweig.io>,
	linux-arm-kernel@lists.infradead.org,
	linuxppc-dev@lists.ozlabs.org, linux-i2c@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH 10/10] i2c: pasemi: Set enable bit for Apple variant
Date: Sun, 26 Sep 2021 11:58:47 +0200	[thread overview]
Message-ID: <20210926095847.38261-11-sven@svenpeter.dev> (raw)
In-Reply-To: <20210926095847.38261-1-sven@svenpeter.dev>

Some later revisions after the original PASemi I2C controller introduce
what likely is an enable bit to the CTL register. Without setting it the
actual i2c transmission is never started.

Signed-off-by: Sven Peter <sven@svenpeter.dev>
---
 drivers/i2c/busses/i2c-pasemi-core.c | 8 ++++++++
 drivers/i2c/busses/i2c-pasemi-core.h | 3 +++
 drivers/i2c/busses/i2c-pasemi-pci.c  | 6 ++++++
 3 files changed, 17 insertions(+)

diff --git a/drivers/i2c/busses/i2c-pasemi-core.c b/drivers/i2c/busses/i2c-pasemi-core.c
index 0ec65263fd08..b52a65beda99 100644
--- a/drivers/i2c/busses/i2c-pasemi-core.c
+++ b/drivers/i2c/busses/i2c-pasemi-core.c
@@ -22,6 +22,7 @@
 #define REG_MRXFIFO	0x04
 #define REG_SMSTA	0x14
 #define REG_CTL		0x1c
+#define REG_REV		0x28
 
 /* Register defs */
 #define MTXFIFO_READ	0x00000400
@@ -37,6 +38,7 @@
 
 #define CTL_MRR		0x00000400
 #define CTL_MTR		0x00000200
+#define CTL_EN		0x00000800
 #define CTL_CLK_M	0x000000ff
 
 static inline void reg_write(struct pasemi_smbus *smbus, int reg, int val)
@@ -60,6 +62,9 @@ static void pasemi_reset(struct pasemi_smbus *smbus)
 {
 	u32 val = (CTL_MTR | CTL_MRR | (smbus->clk_div & CTL_CLK_M));
 
+	if (smbus->hw_rev >= 6)
+		val |= CTL_EN;
+
 	reg_write(smbus, REG_CTL, val);
 }
 
@@ -335,6 +340,9 @@ int pasemi_i2c_common_probe(struct pasemi_smbus *smbus)
 	/* set up the sysfs linkage to our parent device */
 	smbus->adapter.dev.parent = smbus->dev;
 
+	if (smbus->hw_rev != PASEMI_HW_REV_PCI)
+		smbus->hw_rev = reg_read(smbus, REG_REV);
+
 	pasemi_reset(smbus);
 
 	error = devm_i2c_add_adapter(smbus->dev, &smbus->adapter);
diff --git a/drivers/i2c/busses/i2c-pasemi-core.h b/drivers/i2c/busses/i2c-pasemi-core.h
index aca4e2da9089..4655124a37f3 100644
--- a/drivers/i2c/busses/i2c-pasemi-core.h
+++ b/drivers/i2c/busses/i2c-pasemi-core.h
@@ -8,11 +8,14 @@
 #include <linux/io.h>
 #include <linux/kernel.h>
 
+#define PASEMI_HW_REV_PCI -1
+
 struct pasemi_smbus {
 	struct device		*dev;
 	struct i2c_adapter	 adapter;
 	void __iomem		*ioaddr;
 	unsigned int		 clk_div;
+	int			 hw_rev;
 };
 
 int pasemi_i2c_common_probe(struct pasemi_smbus *smbus);
diff --git a/drivers/i2c/busses/i2c-pasemi-pci.c b/drivers/i2c/busses/i2c-pasemi-pci.c
index c1b8901110c0..2b7be35421bc 100644
--- a/drivers/i2c/busses/i2c-pasemi-pci.c
+++ b/drivers/i2c/busses/i2c-pasemi-pci.c
@@ -42,6 +42,12 @@ static int pasemi_smb_pci_probe(struct pci_dev *dev,
 	size = pci_resource_len(dev, 0);
 	smbus->clk_div = CLK_100K_DIV;
 
+	/*
+	 * The original PASemi PCI controllers don't have a register for
+	 * their HW revision.
+	 */
+	smbus->hw_rev = PASEMI_HW_REV_PCI;
+
 	if (!devm_request_region(&dev->dev, base, size,
 			    pasemi_smb_pci_driver.name))
 		return -EBUSY;
-- 
2.25.1


  parent reply	other threads:[~2021-09-26 10:00 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-26  9:58 [PATCH 00/10] Add Apple M1 support to PASemi i2c driver Sven Peter
2021-09-26  9:58 ` [PATCH 01/10] dt-bindings: i2c: Add Apple I2C controller bindings Sven Peter
2021-10-04 18:01   ` Rob Herring
2021-09-26  9:58 ` [PATCH 02/10] i2c: pasemi: Use io{read,write}32 Sven Peter
2021-09-27  7:39   ` Arnd Bergmann
2021-09-28 15:48     ` Sven Peter
2021-09-26  9:58 ` [PATCH 03/10] i2c: pasemi: Remove usage of pci_dev Sven Peter
2021-09-26  9:58 ` [PATCH 04/10] i2c: pasemi: Split off common probing code Sven Peter
2021-09-26  9:58 ` [PATCH 05/10] i2c: pasemi: Split pci driver to its own file Sven Peter
2021-09-26  9:58 ` [PATCH 06/10] i2c: pasemi: Move common reset code to own function Sven Peter
2021-09-26  9:58 ` [PATCH 07/10] i2c: pasemi: Allow to configure bus frequency Sven Peter
2021-09-26  9:58 ` [PATCH 08/10] i2c: pasemi: Refactor _probe to use devm_* Sven Peter
2021-09-26  9:58 ` [PATCH 09/10] i2c: pasemi: Add Apple platform driver Sven Peter
2021-09-29 20:33   ` Wolfram Sang
2021-10-03 14:37     ` Sven Peter
2021-09-26  9:58 ` Sven Peter [this message]
2021-09-27  7:42 ` [PATCH 00/10] Add Apple M1 support to PASemi i2c driver Arnd Bergmann
2021-09-29 20:35   ` Wolfram Sang

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210926095847.38261-11-sven@svenpeter.dev \
    --to=sven@svenpeter.dev \
    --cc=alyssa@rosenzweig.io \
    --cc=arnd@arndb.de \
    --cc=benh@kernel.crashing.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-i2c@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linuxppc-dev@lists.ozlabs.org \
    --cc=marcan@marcan.st \
    --cc=mark.kettenis@xs4all.nl \
    --cc=mohamed.mediouni@caramail.com \
    --cc=mpe@ellerman.id.au \
    --cc=olof@lixom.net \
    --cc=paulus@samba.org \
    --cc=stan@corellium.com \
    --subject='Re: [PATCH 10/10] i2c: pasemi: Set enable bit for Apple variant' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).