From mboxrd@z Thu Jan 1 00:00:00 1970 From: boris.brezillon@free-electrons.com (Boris Brezillon) Date: Wed, 17 Jun 2015 16:39:01 +0200 Subject: [PATCH v2 2/2] clk: at91: modify PMC peripheral clock to deal with newer register layout In-Reply-To: <00aa7c245a7960d6101dad4b284a19cab766ee4a.1434544584.git.nicolas.ferre@atmel.com> References: <62604b586c61f119ffb5942b77eb9b759c17a790.1434544584.git.nicolas.ferre@atmel.com> <00aa7c245a7960d6101dad4b284a19cab766ee4a.1434544584.git.nicolas.ferre@atmel.com> Message-ID: <20150617163901.721cfdd0@bbrezillon> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Wed, 17 Jun 2015 14:40:39 +0200 Nicolas Ferre wrote: > As some more information is added to the PCR register, we'd better use > a copy of its content and modify just the peripheral-related bits. > Implement a read-modify-write for the enable() and disable() callbacks. > > Signed-off-by: Nicolas Ferre Acked-by: Boris Brezillon > --- > v2: - modify header file beforehand so that we can use consistent field naming > > > drivers/clk/at91/clk-peripheral.c | 20 ++++++++++++++------ > 1 file changed, 14 insertions(+), 6 deletions(-) > > diff --git a/drivers/clk/at91/clk-peripheral.c b/drivers/clk/at91/clk-peripheral.c > index 61d0adda7088..1e7dcc57925a 100644 > --- a/drivers/clk/at91/clk-peripheral.c > +++ b/drivers/clk/at91/clk-peripheral.c > @@ -161,14 +161,18 @@ static int clk_sam9x5_peripheral_enable(struct clk_hw *hw) > { > struct clk_sam9x5_peripheral *periph = to_clk_sam9x5_peripheral(hw); > struct at91_pmc *pmc = periph->pmc; > + u32 tmp; > > if (periph->id < PERIPHERAL_ID_MIN) > return 0; > > - pmc_write(pmc, AT91_PMC_PCR, (periph->id & AT91_PMC_PCR_PID_MASK) | > - AT91_PMC_PCR_CMD | > - AT91_PMC_PCR_DIV(periph->div) | > - AT91_PMC_PCR_EN); > + pmc_lock(pmc); > + pmc_write(pmc, AT91_PMC_PCR, (periph->id & AT91_PMC_PCR_PID_MASK)); > + tmp = pmc_read(pmc, AT91_PMC_PCR) & ~AT91_PMC_PCR_DIV_MASK; > + pmc_write(pmc, AT91_PMC_PCR, tmp | AT91_PMC_PCR_DIV(periph->div) > + | AT91_PMC_PCR_CMD > + | AT91_PMC_PCR_EN); > + pmc_unlock(pmc); > return 0; > } > > @@ -176,12 +180,16 @@ static void clk_sam9x5_peripheral_disable(struct clk_hw *hw) > { > struct clk_sam9x5_peripheral *periph = to_clk_sam9x5_peripheral(hw); > struct at91_pmc *pmc = periph->pmc; > + u32 tmp; > > if (periph->id < PERIPHERAL_ID_MIN) > return; > > - pmc_write(pmc, AT91_PMC_PCR, (periph->id & AT91_PMC_PCR_PID_MASK) | > - AT91_PMC_PCR_CMD); > + pmc_lock(pmc); > + pmc_write(pmc, AT91_PMC_PCR, (periph->id & AT91_PMC_PCR_PID_MASK)); > + tmp = pmc_read(pmc, AT91_PMC_PCR) & ~AT91_PMC_PCR_EN; > + pmc_write(pmc, AT91_PMC_PCR, tmp | AT91_PMC_PCR_CMD); > + pmc_unlock(pmc); > } > > static int clk_sam9x5_peripheral_is_enabled(struct clk_hw *hw) -- Boris Brezillon, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com