From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nikolaus Voss Subject: [PATCH v10 0/4] AT91: replace broken TWI driver i2c-at91.c Date: Fri, 20 Apr 2012 12:13:30 +0200 Message-ID: Return-path: Sender: linux-kernel-owner@vger.kernel.org To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-i2c@vger.kernel.org Cc: nicolas.ferre@atmel.com, ben-linux@fluff.org, balbi@ti.com, h.feurstein@gmail.com, rmallon@gmail.com, adrian.yanes@aalto.fi List-Id: linux-i2c@vger.kernel.org The old driver has two main deficencies: i) No repeated start (Sr) condiction is possible, this makes it unusable e.g. for most SMBus transfers. ii) I/O was done with polling/busy waiting what caused over-/underruns even at light system loads and clock speeds. The new driver overcomes these deficencies and in addition allows for more than one TWI interface. A remaining limitation is the fact, that only one repeated start is possible (two concatenated messages). This limitation is imposed by the hardware. However, this should not be a problem as all common i2c-client communication does not rely on more than one repeated start. Signed-off-by: Nikolaus Voss Reviewed-by: Felipe Balbi Tested-by: Hubert Feurstein v10: - applied fix for RXRDY overrun bug submitted by Hubert Feurstein - applied fix for calculating twi_clk v9: - merge i2c-at91.c patches to single patch - rewrite cwgr reg after timeout v8: - remove local include - remove cpu_is_rm9200() and put twi hw bug info in platform_device - use readl/writel_relaxed instead of __raw_readl/writel v7: i) fix bug if internal address > 1 byte ii) send stop when len == 1 (both reported by Carsten Behling) v6: support for I2C_SMBUS_BLOCK_DATA transfers. Better use of clk_(un)prepare(). More sensible transfer timeout. v5: Another round of review comments from Ryan Mallon, Felipe Balbi and Russell King: convert twi clk to use .dev_id, cleanups v4: Integrated more review comments from Ryan Mallon and Felipe Balbi: Moved register include file to local include, code cleanups v3: Integrated review comments from Ryan Mallon and Felipe Balbi v2: Fixed whitespace issue Nikolaus Voss (4): drivers/i2c/busses/i2c-at91.c: remove broken driver Replace clk_lookup.con_id with clk_lookup.dev_id entries for twi clk drivers/i2c/busses/i2c-at91.c: add new driver G45 TWI: remove open drain setting for twi function gpios arch/arm/mach-at91/at91cap9.c | 1 + arch/arm/mach-at91/at91rm9200.c | 1 + arch/arm/mach-at91/at91rm9200_devices.c | 9 + arch/arm/mach-at91/at91sam9260.c | 1 + arch/arm/mach-at91/at91sam9261.c | 1 + arch/arm/mach-at91/at91sam9263.c | 1 + arch/arm/mach-at91/at91sam9g45.c | 2 + arch/arm/mach-at91/at91sam9g45_devices.c | 6 - arch/arm/mach-at91/at91sam9rl.c | 2 + arch/arm/mach-at91/include/mach/at91_twi.h | 68 ---- drivers/i2c/busses/Kconfig | 11 +- drivers/i2c/busses/i2c-at91.c | 579 ++++++++++++++++++---------- 12 files changed, 393 insertions(+), 289 deletions(-) delete mode 100644 arch/arm/mach-at91/include/mach/at91_twi.h -- 1.7.5.4